pms-Carvedilol

Carvedilol.

Each tablet contains 3.125 mg, 6.25 mg, 12.5 mg or 25 mg of carvedilol.
Common Name: Carvedilol.
Chemical Name: 1-(9H-carbazol-4-yloxy)-3-[2-(2-methoxyphenoxy)ethyl]amino]-2-propanol.
Molecular Formula: C₂₄H₂₆N₂O₄.
Molecular Weight: 406.49 g/mol.
Physicochemical properties: Description: White to off-white powder, Racemic form.
Melting point: 113°C - 117°C.
Solubility: Insoluble in water, soluble in acetone and chloroform (1 g in 30 mL).
pKa value at 25°C: 7.9.
Excipients/Inactive Ingredients: Each tablet contains the following non-medicinal ingredients: Colloidal Silicone Dioxide, Crospovidone, Hydroxypropyl Methylcellulose, Lactose, Magnesium Stearate, Microcrystalline Cellulose, Polydextrose, Polyethylene Glycol, Titanium Dioxide, Triethyl Citrate and Povidone.

Pharmacology: Mechanism of Action: Carvedilol is a cardiovascular agent for the treatment of congestive heart failure that combines beta-adrenoceptor blockade and vasodilation in a single racemic mixture. Nonselective beta-adrenoceptor blocking activity is present in the S(-) enantiomer and alpha₁-adrenoceptor blocking activity is present at equal potency in both the R(+) and S(-) enantiomers. Carvedilol has no intrinsic sympathomimetic activity. Its action on beta-receptors is 10 times stronger than on alpha₁-receptors.
Carvedilol reduces peripheral vascular resistance by vasodilation, thereby causing a fall in systemic blood pressure after acute administration, predominantly mediated through selective alpha₁-antagonism. Beta blockade prevents reflex tachycardia with the net result that heart rate is unchanged or decreased. Carvedilol reduces renin release through beta blockade.
The mechanism for the beneficial effects of carvedilol in congestive heart failure has not been established.
Detailed Pharmacology: Beta-adrenoceptor blocking activity has been demonstrated in animal and human studies by showing that carvedilol 1) reduces exercise- and/or isoproterenol-induced tachycardia, and 2) reduces reflex orthostatic tachycardia. Significant beta-adrenoceptor blocking effect is usually seen within 1 hour of oral drug administration (in the fasting state). Carvedilol is not cardioselective, does not have intrinsic sympathomimetic activity, and possesses some membrane stabilizing activity.
Alpha₁-adrenoceptor blocking activity has been demonstrated in animal and human studies by showing that carvedilol 1) attenuates the pressor effects of phenylephrine but not of angiotensin II, 2) causes vasodilation; and 3) reduces peripheral vascular resistance. The onset of these effects is usually seen within 30 minutes of oral drug administration (in the fasting state).
In animal in vivo studies, and in human in vitro studies, carvedilol has been shown to have antioxidant activity. Some metabolites are ten-fold more potent than carvedilol in this regard, although these metabolites are found at serum concentrations ten-fold lower than those of carvedilol. The carbazole portion of the molecule is responsible for this antioxidant activity, which is found to be equally potent in each enantiomer; the beta-blocking and vasodilating actions reside in other parts of the molecular structure and both enantiomers of carvedilol are equally potent as antioxidants. The clinical significance of the antioxidant effect has not been established.
Pharmacodynamics: In two studies that compared the acute hemodynamic effects of carvedilol to baseline measurements in patients with congestive heart failure, there were significant reductions in systemic blood pressure, pulmonary artery pressure, pulmonary capillary wedge pressure, and heart rate. Initial effects on cardiac output, stroke volume index and systemic vascular resistance were small and variable.
In terms of chronic hemodynamic effects (12 to 14 weeks), carvedilol significantly reduced systemic blood pressure, pulmonary artery pressure, right atrial pressure, systemic vascular resistance and heart rate while stroke volume index was increased.
Clinical Trials: See Tables 1 & 2.

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In a US multicentre program, 1197 patients with stable symptomatic congestive heart failure, NYHA class II to IV, were challenged with a low dose of carvedilol (3.125 or 6.25 mg twice daily) for 2 to 4 weeks to determine tolerability. Of these patients, 1094 were then randomized to double-blind treatment with carvedilol (n=696) or placebo (n=398) and stratified to one of four studies based on baseline exercise performance, with the prestated objective to evaluate total mortality. The average duration of therapy on carvedilol was 6.5 months in this program. Patients entering the program had symptomatic congestive heart failure due to ischemic or non-ischemic cardiomyopathy with an ejection fraction ≤ 35%. All patients received conventional therapy, i.e. diuretics, angiotensin-converting enzyme (ACE) inhibitors, if tolerated, with or without digoxin.
On an intent-to-treat basis, total mortality in this program was 3.2% in the carvedilol group and 7.8% in the placebo group. Thus, a relative risk reduction of 65% (95% confidence limits 39 and 80%, p=0.001) was observed. Treatment with carvedilol was associated with a significant decrease in the relative risk of death from progressive pump failure (81%, p=0.001) and the relative risk of sudden death (56%, p=0.033). The incidence of cardiovascular hospitalizations was 13% in the carvedilol group and 21% in the placebo group, with a relative risk reduction of 36% (95% confidence limits 14% and 53%, p=0.004).
Improved patient well-being was observed with carvedilol treatment in the US multicentre program, as indicated by a change in the NYHA class from baseline to endpoint for the four US phase III placebo-controlled studies. The overall between-group difference in distributions, stratified by protocol and baseline classification, was significant (p<0.001) and as also indicated by patient and physician global assessments during US Phase III trials, 78% of patients in the carvedilol group rated their condition as improved compared to 63% in the placebo group (p values over four studies from 0.001 to 0.032). However, exercise tolerance was not improved.
In a large multicenter trial of carvedilol, performed in Australia and New Zealand, 443 patients with stable symptomatic congestive heart failure NYHA Class I to III, were challenged with a low dose of carvedilol (3.125 mg or 6.25 mg twice daily) for 2 to 4 weeks to determine tolerability. Of these patients, 415 were then randomized to double-blind treatment with carvedilol (n=207) or placebo (n=208). The average duration of therapy on carvedilol was 16.1 months in this study. Patients entering the program had symptomatic congestive heart failure due to ischemic cardiomyopathy with an ejection fraction ≤ 45%. All patients received conventional therapy, i.e. diuretics, (ACE) inhibitors, if tolerated, with or without digoxin.
On an intent-to-treat basis, total mortality in this Australia and New Zealand trial was 10.1% in the carvedilol group and 13.9% in the placebo group, a non-statistically significant relative risk reduction of 29% (confidence limits -24% and 59%, p=0.231). Cardiovascular hospitalizations were 31% in the carvedilol group and 40% in the placebo group, a relative risk reduction of 28% (95% confidence limits: 1% and 48%, p=0.044). Patient well-being, as judged by NYHA class or Specific Activity Scale rating, as well as exercise tolerances were no different in the carvedilol group compared to the placebo group.
In the COPERNICUS trial, 2289 patients with severe heart failure were randomly assigned to treatment with placebo or carvedilol for up to 29 months. Patients had symptoms at rest or on minimal exertion and had a left ventricular ejection fraction < 25% (mean 20%), despite treatment with diuretics (99%), an ACE inhibitor (89%), and digitalis (66% worldwide, 85% within Canada) for more than 2 months. Patients with cardiac impairment not related to left ventricular dysfunction were excluded as were patients with prior cardiac transplant, cardioplasty, unstable angina, myocardial infarction, destabilizing cardiac arrhythmias, or treatment within 1 month with an α-adrenoceptor antagonist (except for prostatism), a calcium channel blocker or a class I antiarrhythmic agent. The trial was followed by a data safety monitoring committee, which stopped the trial early after a median follow-up of 10.4 months because of an observed reduction in total mortality, the primary endpoint, from 19.7% per patient-year on placebo to 12.8% per patient-year on carvedilol, (a relative risk reduction of 35%; hazard ratio 0.65, 95% CI 0.52 and 0.81, and a P value adjusted for interim analyses of 0.0014). The results are summarized in Table 3 and the figure. (See Table 3 and figure.)

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Pharmacokinetics: See Table 4.

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Absorption: Carvedilol is rapidly absorbed following oral administration, with peak plasma concentrations of carvedilol observed at 1 hour post-dose in fasting subjects. Despite being well-absorbed, absolute bioavailability is approximately 25% to 35% due to a significant degree of first-pass metabolism.
Plasma concentrations achieved are proportional to the oral dose administered. When administered with food, the rate of absorption is slowed, as evidenced by a delay in time to reach peak plasma concentrations (about 2.3 hours post-dose), with no significant difference in extent of bioavailability.
Distribution: Carvedilol is highly bound to plasma proteins, (greater than 98%) primarily to albumin. The plasma-protein binding is independent of concentration over the therapeutic range. Carvedilol is a basic, lipophilic compound with a steady-state volume of distribution of approximately 115 L.
Metabolism: Following oral administration, the apparent mean terminal elimination half-life of carvedilol ranges from 7 to 10 hours. Plasma clearance ranges from 500 to 700 mL/min. Carvedilol is extensively metabolized with less than 2% of the dose excreted unchanged in the urine. Carvedilol is metabolized mainly by glucuronidation and aromatic ring oxidation by the cytochrome P450 system (primarily CYP2D6 and CYP2C9 isozymes). The metabolites of carvedilol are excreted mainly via the bile into the feces.
Excretion: Elimination is mainly biliary. The primary route of excretion is via the feces.
A minor part is eliminated via the kidneys in the form of various metabolites.
Carvedilol undergoes stereoselective first-pass metabolism with plasma levels of R(+)-carvedilol approximately 2- to 3-fold higher than S(-)-carvedilol following oral administration in healthy subjects. The mean apparent terminal elimination half-life for R(+)-carvedilol ranges from 5 to 9 hours compared with 7 to 11 hours for the S(-) enantiomer.
There are at least 5 pharmacologically active metabolites of carvedilol: desmethyl, 4'-hydroxyphenyl, 5'-hydroxyphenyl, 1-hydroxycarbazolyl and 8-hydroxycarbazolyl metabolites. Each of these metabolites has two enantiomeric forms and each metabolite possesses different relative potencies with regard to α- and β-receptor blocking activities. Plasma concentrations of these metabolites are 10- to 50-fold lower than those observed for the parent compound. Therefore, even for metabolites that are more active or at least as active as carvedilol itself, they are present at such low concentrations that they would produce effects less than, or at least not greater than, the parent compound.
Special Populations and Conditions: Geriatrics: Compared to young subjects (18 to 43 years old), AUC values for carvedilol were, on average, 38% higher in elderly (65 to 76 years old) subjects. Moreover, AUC values were 50% higher for S(-)-carvedilol and 23% for R(+)-carvedilol in the elderly compared to the young subjects. Changes in C_max values for carvedilol and its enantiomers were less pronounced, approximately 8% to 17% higher in elderly subjects with no apparent change in T_max. Although the terminal elimination half-lives of carvedilol were similar in both young and elderly subjects, the initial decline in plasma concentrations in the elderly appeared to be slower than in the young subjects suggesting a decrease in systemic clearance of carvedilol in the elderly (see Precautions and Dosage & Administration).
Hepatic Insufficiency: In patients with cirrhotic liver disease, the absolute bioavailability of carvedilol was 4 times greater as compared to healthy subjects with median C_max and AUC values for carvedilol 4 to 7 times higher in patients with liver disease following oral administration (see Contraindications and Precautions).
Renal Insufficiency: Although carvedilol is metabolized primarily by the liver, plasma concentrations of carvedilol have been reported to be increased in patients with renal impairment. Based on AUC data, approximately 40% to 50% higher plasma concentrations of carvedilol were observed in hypertensive patients with moderate to severe renal impairment compared to a control group of hypertensive patients with normal renal function. However, the ranges of AUC values were similar for both groups. Changes in C_max data were less pronounced, approximately 12% to 26% higher in patients with impaired renal function.
The pharmacokinetics of carvedilol are not altered by hemodialysis.
Patients with Congestive Heart Failure: Steady-state plasma concentrations of carvedilol and its enantiomers increased proportionally over the 6.25 to 50 mg b.i.d. dose range in patients with congestive heart failure. Compared to healthy subjects, patients with Class IV congestive heart failure had increased mean AUC and C_max values for carvedilol and its enantiomers with up to 50% to 100% higher values than normal volunteers. The mean apparent terminal elimination half-life for carvedilol was similar to that observed in healthy subjects.
Genetic Polymorphism: Carvedilol is subject to genetic polymorphism with poor metabolizers of debrisoquin (deficient in CYP2D6) exhibiting 2- to 3-fold higher plasma concentrations of the R(+)-carvedilol compared to extensive metabolizers. In contrast, plasma levels of S(-)-carvedilol are increased only about 20% to 25% in poor metabolizers, indicating that the metabolism of this enantiomer is affected to a lesser extent by CYP2D6 than R(+)-carvedilol. The pharmacokinetics of carvedilol enantiomers do not appear to be different in poor metabolizers of S-mephenytoin, i.e., deficient in CYP2C19.
Toxicology: LD₅₀ values in mg/kg after 14 days observation time (n=10 for all groups): See Table 5.

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Almost all deaths occurred one to two days after dosing. No systemic clinical signs were observed in the animals treated orally. Animals dosed parenterally (except doses intraperitoneally) showed transient apathy and ptosis.
Long-Term Toxicity: Carvedilol was administered daily for 12 months to 5 dogs/sex/group at 0, 10, 30, 100, and 300 mg/kg given orally in two divided doses. Carvedilol was also administered daily in the food for 12 months to 30 rats/sex/group at doses of 30, 100, or 300 mg/kg and in another study for 18 months to 30 rats/sex/group at doses of 10, 31, 89, 261 mg/kg. Following oral administration, no toxic effects were seen at 10 mg/kg in the dog and at 30 mg/kg in the rat. These no-effect doses are 14 and 42 times higher than a relatively high therapeutic dose in humans (based on a daily dose of 50 mg in a 70 kg patient).
Teratology Studies: Teratology studies show no evidence of carvedilol having teratogenic effects. In the fertility study, high doses resulted in reduced fertility and diminished general reproductive capacity in the F₀ generation and retardation in physical development in the F₁ generation. These adverse effects are regarded as nonspecific effects due to loading the parental generation with toxic dosages.
Mutagenicity Studies: No mutagenic potential of carvedilol was demonstrated in several in vitro and in vivo test systems.
Carcinogenicity Studies: Two-year carcinogenicity studies were conducted in both mice and rats. In the mouse study, groups of 50 mice/sex/group received daily doses of 20, 65 or 200 mg/kg in the diet. A group of 100 mice/sex/group were untreated and served as controls. In the rat study, groups of 50 rats/sex/group received 0, 200, 400, 800, or 1600 ppm carvedilol in the diet. These concentrations corresponded to daily dosages at the start of the study up to 21.7, 43, 86.7 and 169.5 mg/kg. Since the carvedilol dietary concentration did not change throughout the study and the animals gained weight, by the end of the study the actual daily dosages decreased to 9.5, 18.8, 38.1 and 74.7 mg/kg.
The results of the histopathologic examinations from these carcinogenicity studies indicated that carvedilol does not have either a tumorigenic or a carcinogenic potential.

pms-CARVEDILOL (carvedilol) is indicated for the treatment of mild, moderate or severe heart failure of ischemic or non-ischemic origin to increase survival and also, to reduce the combined risk of all-cause mortality and cardiovascular or non-cardiovascular hospitalizations.
In general, pms-CARVEDILOL is used in conjunction with diuretics and an ACE inhibitor, with or without digitalis.
pms-CARVEDILOL should be prescribed by a physician experienced in the treatment of heart failure.

Dosing Considerations: Dosage must be individualized and patients closely monitored during initiation and up-titration by a physician experienced in the treatment of heart failure.
All patients in whom pms-CARVEDILOL therapy is to be considered must be clinically stable for 4 weeks prior to initiation of pms-CARVEDILOL.
Prior to initiation of pms-CARVEDILOL therapy, patients should be on stable doses of diuretics and angiotensin converting enzyme inhibitors, with or without digitalis. In clinical trials, all patients shown to have benefit were on the previously mentioned regimen unless they were intolerant to an ACE inhibitor.
Recommended Dose and Dosage Adjustment: The recommended starting dose of pms-CARVEDILOL is 3.125 mg twice daily for two weeks. If this dose is tolerated, it can then be increased to 6.25, 12.5 and 25 mg twice daily over successive intervals of at least 2 weeks. Patients should be maintained on the highest tolerated dose. The maximum recommended dose is 25 mg twice daily. The dose of pms-CARVEDILOL should not be increased until symptoms of worsening heart failure or vasodilation have stabilized.
Patients should be advised that initiation of treatment and, to a lesser extent, dosage increases may be associated with transient symptoms of dizziness or light-headedness, and rarely syncope, within the first 2 hours after dosing. During these periods, they should avoid situations such as driving or dangerous tasks where symptoms could result in injury. In addition, pms-CARVEDILOL should be taken with food to slow the rate of absorption and reduce the incidence of orthostatic effects, especially during up-titration. Symptoms of hypotension do not often require treatment, but it may be useful to separate the time of dosing of pms-CARVEDILOL from that of the ACE inhibitor, or to reduce temporarily the dose of the ACE inhibitor.
The risk/benefit of carvedilol therapy in clinically stable heart failure patients with a heart rate lower than 68 beats per minute should be carefully considered prior to initiation of pms-CARVEDILOL since carvedilol has not been studied in these patients (see Precautions).
Before each dose increase the patient should be seen in the office and evaluated for symptoms of worsening heart failure, vasodilation (dizziness, light-headedness, symptomatic hypotension) or bradycardia, in order to determine tolerability of pms-CARVEDILOL. Transient worsening of heart failure may be treated with increased doses of diuretics, lowering the dose of pms-CARVEDILOL or, if necessary, discontinuation of pms-CARVEDILOL. Symptoms of vasodilation such as dizziness, light-headedness or decreasing blood pressure may respond to a reduction in the dose of diuretics. If these changes do not relieve symptoms, the dose of pms-CARVEDILOL should be decreased. If the dose of pms-CARVEDILOL was decreased, it should not be increased again until symptoms of worsening heart failure or vasodilation have been stabilized for 2 weeks. Initial difficulty with titration may not preclude later attempts to re-introduce or resume titration of pms-CARVEDILOL; however, caution is required in these circumstances. If congestive heart failure patients experience bradycardia (pulse rate below 55 beats/min.), the dose of pms-CARVEDILOL should be reduced, or may require discontinuation.
Elderly: The frequency and pattern of adverse reactions in patients ≥ 65 years was similar to that in younger patients. However, plasma levels of carvedilol are higher in older patients compared to younger patients (see Precautions). Therefore, after initiating pms-CARVEDILOL at the same dose in the elderly as in younger patients, up-titration should be done more cautiously in the elderly. A lower total daily dose may be reached at the end of up-titration in such patients compared to younger patients.
Hepatic Insufficiency: pms-CARVEDILOL is contraindicated in patients with clinically manifest liver disease (see Contraindications). In patients with milder hepatic impairment, there is a potential for increased manifestations of vasodilation and beta-blockade (see Pharmacology: Pharmacokinetics under Actions; and Precautions). Therefore, after initiating pms-CARVEDILOL at the same dose in patients with hepatic impairment as in other patients, up-titration should be done more cautiously in patients with hepatic impairment. A lower total daily dose may be reached at the end of up-titration in such patients compared to other patients.
Renal Insufficiency: Acute, reversible renal failure has been seen in some patients treated with Carvedilol; particularly those with underlying renal impairment (see Precautions). Therefore, after initiating pms-CARVEDILOL at the same dose in patients with renal impairment as in other patients, up-titration should be done more cautiously in patients with renal impairment. Renal function (BUN and creatinine) should be checked in such patients as appropriate. If renal function has deteriorated, the dose of pms-CARVEDILOL may need to be reduced or discontinued.
Discontinuation: pms-CARVEDILOL should be gradually reduced over a period of about 2 weeks, if possible, and the patient should be carefully observed (see General: Abrupt Cessation of Therapy under Precautions).

Cases of overdosage with carvedilol alone or in combination with other drugs have been reported. Quantities ingested in some cases exceeded 1000 mg. Clinical signs experienced included low blood pressure and heart rate. Standard supportive treatment was provided and individuals recovered.
In the event of inadvertent or intentional overdosage with carvedilol, there may be severe hypotension, excessive bradycardia, heart failure, cardiogenic shock, and cardiac arrest due to its pharmacologic activities. There may also be respiratory distress, bronchospasm, vomiting, disturbed consciousness, and generalized seizures.
Patients who have taken an overdose of carvedilol should be placed supine, with their legs raised. For removal of the drug shortly after ingestion, gastric lavage or pharmacologically induced emesis may be useful. Carvedilol is not removed by hemodialysis. In addition to these general procedures, the patient's vital signs should be monitored under intensive care conditions with continuous monitoring, if necessary.
The following additional supportive therapies can be used: If excessive hypotension occurs, vasopressors, norepinephrine or noradrenaline should be administered with continuous monitoring of the circulatory system. Digitalis, diuretics, and if necessary, dopamine or dobutamine should be administered if cardiac failure occurs.
For excessive bradycardia, atropine 0.5 to 2 mg should be given intravenously. In addition, glucagon 1 to 10 mg given intravenously over 30 seconds initially, followed by a continuous infusion of 2 to 2.5 mg/h, has been shown to be effective when severe overdosage of beta blockers causes hypotension and or bradycardia. For therapy-resistant bradycardia, pacemaker therapy may be necessary.
For bronchospasm, beta-sympathomimetics (as aerosol or intravenously) or intravenous aminophylline should be given.
In the event of seizures, slow intravenous injection of diazepam or clonazepam is recommended.
NOTE: In the event of severe intoxication where there are symptoms of shock, treatment must be continued for a sufficiently long period of time consistent with the 7 to 10 hour elimination half-life of carvedilol.
For management of a suspected drug overdose, contact the regional Poison Control Centre immediately.

Carvedilol is contraindicated in patients with: decompensated cardiac failure requiring intravenous inotropic therapy with sympathomimetic agents; bronchial asthma or related bronchospastic conditions (see Precautions); second- or third-degree AV block, or sick sinus syndrome (unless a permanent pacemaker is in place); cardiogenic shock; severe hypotension (see Precautions); severe bradycardia (see Precautions); primary obstructive valvular heart disease; clinically manifest hepatic impairment (jaundice, ascites, spider angiomata, esophageal varices, etc.); mental incapacity (e.g. severe Alzheimer's, alcoholism, drug abuse), unless closely supervised by an appropriate caregiver; hypersensitivity to carvedilol or any component of carvedilol tablets. For a complete listing, see Description.

Beta blockers can cause worsening heart failure (see Precautions). Since carvedilol has beta-blocking properties, care must be taken during initiation and up-titration of the drug in heart failure patients, since worsening heart failure has been observed during this phase of treatment. In order to minimize the risk of these events, it is critical to carefully follow the recommended dosing for pms-CARVEDILOL in patients with congestive heart failure (see Dosage & Administration).

General: Abrupt Cessation of Therapy: In patients with heart failure treated chronically with carvedilol, abrupt cessation of therapy may lead to deterioration. Therefore discontinuation of carvedilol should be done gradually, if possible.
Patients with ischemic heart disease should be warned against abrupt discontinuation of beta-adrenergic blocking agents. There have been reports of severe exacerbation of angina, and of myocardial infarction or ventricular arrhythmias occurring in patients with angina pectoris, following abrupt discontinuation of beta-blocker therapy.
The last two complications may occur with or without preceding exacerbation of angina pectoris. Therefore, when discontinuing carvedilol in patients with angina pectoris, the dosage should be gradually reduced over a period of about 2 weeks and the patient should be carefully observed. The same frequency of administration should be maintained. In situations of greater urgency, carvedilol therapy should be discontinued stepwise and under conditions of closer observation. If angina markedly worsens or acute coronary insufficiency develops, it is recommended that treatment with the drug be re-instituted promptly, at least temporarily.
Oculomucocutaneous Syndrome: Various skin rashes and conjunctival xerosis have been reported with beta-blockers. A severe syndrome (oculomucocutaneous syndrome) whose signs include conjunctivitis sicca and psoriasiform rashes, otitis, and sclerosing serositis has occurred with the chronic use of one beta-adrenergic blocking agent (practolol). This syndrome has not been observed in association with carvedilol or any other such agent. However, physicians should be alert to the possibility of such reactions and should discontinue treatment in the event that they occur.
Cardiovascular: Cardiac Failure: Worsening cardiac failure may occur during initiation and up-titration of carvedilol. Sympathetic stimulation is a vital component supporting circulatory function in congestive heart failure, and inhibition with beta-blockade may further depress myocardial contractility.
Cardiac failure should be controlled for at least 4 weeks before carvedilol treatment is initiated. In clinical trials of mild to moderate heart failure, patients were required to be on stable doses of diuretics and ACE inhibitors (if tolerated) prior to the initiation of carvedilol. Despite these steps to ensure stability, a small number of patients with mild to moderate heart failure developed worsening heart failure. During the initiation of therapy (doses of 3.125 to 6.25 mg b.i.d. over 2 to 4 weeks) 6.0% of patients developed worsening congestive heart failure. During up-titration (12.5 to 50 mg b.i.d. over 2 to 6 weeks), worsening heart failure was reported in 5.1% of treated patients treated with carvedilol and in 4.1% of placebo patients.
In a placebo-controlled trial of patients with severe heart failure (COPERNICUS trial), worsening heart failure occurred during up-titration although the frequency reported during the first 3 months was similar with carvedilol (15.4%) and with placebo (14.8%). When treatment was maintained beyond 3 months, worsening heart failure was reported less frequently in patients treated with carvedilol than with placebo. Worsening heart failure observed during long-term therapy is more likely to be related to the patients' underlying disease than to treatment with carvedilol.
Administration of carvedilol to patients with controlled heart failure must be carried out under careful supervision. If symptoms occur, diuretics should be increased and the carvedilol dose not advanced or even lowered until clinical stability resumes (see Dosage & Administration). However, it may be necessary to discontinue carvedilol. Such episodes may not preclude subsequent successful titration of the drug or a favorable response to carvedilol.
Hypotension: Hypotension and postural hypotension in congestive heart failure patients occurred with a higher incidence in carvedilol-treated than in placebo-treated patients (see Adverse Reactions). The risk of these events was highest during initiation of therapy and during the first 30 days of dosing corresponding to the up-titration period. Therefore, it is of critical importance that the dosing recommendation be followed (see Dosage & Administration).
Peripheral Vascular Disease: Beta-blockers can precipitate or aggravate symptoms of arterial insufficiency in patients with peripheral vascular disease. Caution should be exercised in such individuals.
Primary Regurgitative Valvular Heart Disease: Carvedilol should be used with caution in patients with primary regurgitative valvular disease as experience in this patient population is limited.
Prinzmetal's Angina: Beta-blocking agents may provoke chest pain in patients with Prinzmetal's angina. There has been no clinical experience with carvedilol in these patients. Caution should be taken in the administration of carvedilol to patients suspected of having Prinzmetal's variant angina.
Sinus Bradycardia: Severe sinus bradycardia may occur with the use of carvedilol. In such cases, dosage should be discontinued.
In clinical trials, patients with a resting heart rate of less than or equal to 68 beats/minute prior to initiation of carvedilol were not studied.
Endocrine and Metabolism: Diabetes: Carvedilol should be administered with caution to patients subject to spontaneous hypoglycemia, or to diabetic patients (especially those with labile diabetes) who are receiving insulin or oral hypoglycemic agents. Beta-adrenergic blocking drugs may enhance hypoglycemia, in patients prone to this condition. Also, diabetics on insulin or oral hypoglycemic medication may have an increased tendency towards hypoglycemia when treated with these drugs. It may also be necessary to adjust the dosage of oral hypoglycemics or insulin. Early signs of acute hypoglycemia, especially tachycardia, may be masked or attenuated. Regular monitoring of blood glucose is therefore recommended when carvedilol is initiated, adjusted or discontinued.
Hyperthyroidism: In patients with thyrotoxicosis, possible deleterious effects from long-term use of carvedilol have not been appraised. Beta-blockade, in general, may mask the clinical signs of continuing hyperthyroidism or complications, and give a false impression of improvement. Therefore, abrupt withdrawal of carvedilol may be followed by an exacerbation of the symptoms of hyperthyroidism, including thyroid storm.
Pheochromocytoma: The effect of carvedilol in patients with pheochromocytoma has not been studied. Since paradoxical hypertensive responses have been reported in a few patients with this tumor when treated with β-blockers, physicians should use caution when administering carvedilol to patients with pheochromocytoma.
Hepatic: Hepatocellular injury, confirmed by rechallenge, has occurred rarely with carvedilol therapy.
Hepatic injury has been reversible and has occurred after short- and/or long-term therapy with minimal clinical symptomatology. No deaths due to liver function abnormalities have been reported in association with the use of carvedilol.
At the first symptom/sign of liver dysfunction (e.g. pruritus, dark urine, persistent anorexia, jaundice, right upper quadrant tenderness or unexplained "flu-like" symptoms) laboratory testing should be performed. If the patient has laboratory evidence of liver injury or jaundice, carvedilol treatment should be stopped and not restarted.
Hepatic Impairment: Since carvedilol undergoes first-pass metabolism in the liver, reduced hepatic metabolism could lead to greater systemic bioavailability of carvedilol in patients with hepatic impairment. Care should be taken in selecting an appropriate dosage regimen for these patients (see Contraindications and Dosage & Administration). Physicians should be aware of the potential for increased manifestations of vasodilation (dizziness, postural hypotension, hypotension, syncope) or beta-blockade (bradycardia, AV block) in patients with mild hepatic impairment receiving carvedilol (see Dosage & Administration).
Immune: Allergic Reaction: There may be increased difficulty in treating an allergic-type reaction in patients on beta-blockers. In these patients, the reaction may be more severe due to pharmacological effects of beta-blockers and problems with fluid changes. Epinephrine should be administered with caution since it may not have its usual effects in the treatment of anaphylaxis.
On the one hand, larger doses of epinephrine may be needed to overcome the bronchospasm, while on the other; these doses can be associated with excessive alpha-adrenergic stimulation with consequent hypertension, reflex bradycardia and heart block and possible potentiation of bronchospasm. Alternatives to the use of large doses of epinephrine include vigorous supportive care such as fluids and the use of beta agonists including parenteral salbutamol or isoproterenol to overcome bronchospasm and norepinephrine to overcome hypotension.
Ophthalmologic: Contact Lens Use: Wearers of contact lenses should bear in mind the possibility of reduced lacrimation.
Uveal Binding: Animal studies have shown that carvedilol binds to the melanin of the uveal tract. The significance of this in humans is not known but periodic ophthalmic examinations are advisable while the patient is taking carvedilol.
Peri-Operative Considerations: Because of the synergistic negative inotropic and vasodilating effects of carvedilol and anesthetic drugs, the potential for pronounced hypotension during anesthesia exists. If carvedilol treatment is to be continued preoperatively, particular care should be taken when anesthetic agents which depress myocardial function are used.
Renal: Rarely, use of carvedilol in patients with congestive heart failure has resulted in acute renal failure and deterioration of renal function, likely on a pre-renal basis. Patients at risk appear to be those with low blood pressure (systolic BP < 100 mmHg), ischemic heart disease and diffuse vascular disease, and/or underlying renal insufficiency. Renal function has returned to baseline when carvedilol was stopped. In patients with these risk factors it is recommended that renal function be monitored during up-titration of carvedilol and the drug discontinued or dosage reduced if worsening of renal function occurs (see Dosage & Administration).
Respiratory: Bronchospasm (e.g. chronic bronchitis and emphysema): Patients with bronchospastic disease should, in general, not receive β-blockers (see Contraindications).
In clinical trials of patients with congestive heart failure, patients with bronchospastic disease were enrolled if they did not require oral or inhaled medication to treat their bronchospastic disease. In such patients, it is recommended that carvedilol be used with caution. The dosing recommendations should be followed closely and the dose should be lowered if any evidence of bronchospasm is observed during up-titration.
Use in the Elderly: Pharmacokinetic studies indicate that AUC and T_max values are increased in elderly patients. Plasma levels of carvedilol averaged about 38% higher in elderly compared to young subjects. Therefore, dosage adjustments should be made with particular caution (see Dosage & Administration).
Use in Lactation: Carvedilol and/or its metabolites are excreted in breast milk. Therefore, breast feeding is not recommended during administration of carvedilol.
Use in Children: Safety and efficacy in children have not been established.
Use in Pregnancy: There have been no clinical studies carried out to specifically examine the use of carvedilol in pregnant women. Beta-blockers reduce placental perfusion, which may result in intrauterine fetal death, immature and premature deliveries. In addition, adverse effects (especially hypoglycemia and bradycardia) may occur in the fetus and neonate. There is an increased risk of cardiac and pulmonary complications in the neonate in the postnatal period.
Animal reproduction studies have revealed no teratogenic potential for carvedilol. Embryotoxicity was observed only after large doses in rabbits. The relevance of these findings for humans is uncertain.
Carvedilol should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Nursing Women: Carvedilol and/or its metabolites are excreted in breast milk. Therefore, breast feeding is not recommended during administration of carvedilol.
Pregnant Women: There have been no clinical studies carried out to specifically examine the use of carvedilol in pregnant women. Beta-blockers reduce placental perfusion, which may result in intrauterine fetal death, immature and premature deliveries. In addition, adverse effects (especially hypoglycemia and bradycardia) may occur in the fetus and neonate. There is an increased risk of cardiac and pulmonary complications in the neonate in the postnatal period.
Animal reproduction studies have revealed no teratogenic potential for carvedilol. Embryotoxicity was observed only after large doses in rabbits. The relevance of these findings for humans is uncertain.
Carvedilol should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.

Overview: Mild to Moderate Heart Failure - Controlled Trials: The most frequent adverse experiences reported in the double-blind phase of the US clinical trial experience (see Table 6) in patients with mild to moderate heart failure treated with carvedilol were dizziness (32.4%), fatigue (23.9%), dyspnea (21.3%), upper respiratory infection (18.3%) cardiac failure (15.3%) and chest pain (14.4%).
During the double-blind phase of six US placebo controlled trials, adverse experiences rated as serious were reported in 22.4% of patients treated with carvedilol and 31.8% in the placebo group. The most serious adverse experiences reported with carvedilol were cardiac failure (5.6%), syncope (1.8%), bradycardia (1.6%), hypotension (1.3%), myocardial infarction (0.9%), acute renal failure (0.8%), and AV block (0.7%).
Of the 1202 patients who received randomized treatment in these trials, 5.4% of patients treated with carvedilol withdrew because of adverse experiences compared with 8.0% of placebo patients. Bradycardia, fatigue, hypotension, dizziness and dyspnea were the most commonly reported adverse experiences leading to discontinuation in patients treated with carvedilol (see Table 6).
Six deaths occurred in 1319 patients enrolled in the screening phase (3 to 4 weeks), 11 deaths occurred in 1313 patients challenged with carvedilol (2 to 4 weeks). There were 8 deaths (3/765 carvedilol; 5/437 placebo) during up titration phase (2 to 6 weeks) and 47 deaths (20/765 carvedilol; 27/437 placebo) during the maintenance phase (up to 12 months) of the studies.
Withdrawals due to worsening heart failure in U.S placebo controlled trials were as follows: during challenge 1.4% of patients (18/1313 for 2 to 4 weeks); during up-titration 0.9% (7/765) of patients treated with carvedilol and 0% (0/437) of placebo patients (2 to 6 weeks); during the maintenance phase 0.7% (5/765) of patients treated with carvedilol and 2.3% (10/437) of placebo patients (up to 12 months).
Worsening renal function, including acute renal failure (see Table 6), has been seen in some patients (carvedilol 9.5% and placebo 7.6%). Patients at greatest risk include those with pre-existing renal insufficiency, hypotension and ischemic cardiomyopathy, previous renal insufficiency due to ACE inhibitors, diffuse vascular disease, or evidence of renal artery stenosis.
Severe Heart Failure - Controlled Trials: The most frequent adverse experiences reported in a clinical trial in patients with severe heart failure treated with carvedilol were dizziness (24.1%), hypotension (13.9%) and upper respiratory infection (13.6%) (see Table 7). Median study exposure was 10.4 months for both carvedilol and placebo patients.
Clinical Trial Adverse Drug Reactions: Because clinical trials are conducted under very specific conditions the adverse reaction rates observed in the clinical trials may not reflect the rates observed in practice and should not be compared to the rates in the clinical trials of another drug. Adverse drug reaction information from clinical trials is useful for identifying drug-related adverse events and for approximating rates.
Mild to Moderate Heart Failure - Controlled Trials: In six US placebo controlled trials, 1313 patients were challenged with carvedilol over a 2 - 4 week period. Of these patients, 1202 were randomized to double blind treatment with carvedilol (n=765) or placebo (n=437). 92.5% of those treated with carvedilol reported at least one adverse experience.
Adverse experiences rated as severe in intensity during the double-blind phase of these trials were reported in 24.3% of patients treated with carvedilol. The most frequent severe adverse experiences were cardiac failure (2.9%), fatigue (2.2%), dizziness (2.0%), dyspnea (1.8%), and syncope (1.7%).
Table 6 shows adverse events reported in patients with mild to moderate heart failure enrolled in U.S. placebo-controlled clinical trials. Shown are adverse events that occurred more frequently in carvedilol-treated patients than placebo-treated patients with an incidence >1% regardless of causality. Median study medication exposure was 6.3 months for carvedilol and placebo patients. (See Table 6.)

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In addition to the events in Table 6, the following events occurred in more than 1% of patients treated with carvedilol but rates were equal to, or more common in, placebo-treated patients: asthenia, cardiac failure, flatulence, anorexia, dyspepsia, palpitation, ventricular tachycardia, atrial fibrillation, extrasystoles, bilirubinemia, hyperkalemia, arthritis, angina pectoris, insomnia, depression, amnesia, anemia, viral infection, dyspnea, coughing, respiratory disorder, pneumonia, rhinitis, rash, pruritus, and leg cramps.
Adverse experiences related to laboratory parameters reported in greater than 1% of patients are in Table 6. Adverse experiences related to laboratory parameters reported in ≤1% but more than 0.1% of patients included increased hepatic enzymes (0.4% of congestive heart failure patients were discontinued from therapy because of increases in hepatic enzymes; see Hepatic: Hepatic Impairment under Precautions), hypokalemia, hypertriglyceridemia, anemia, leukopenia.
Severe Heart Failure - Controlled Trial: In a clinical trial in severe heart failure that compared carvedilol in daily doses of 50 mg (n=1156) with placebo (n=1133), 9.4% of patients treated with carvedilol discontinued treatment for adverse experiences versus 11.2% of placebo patients.
Table 7 shows adverse events reported in patients with severe heart failure enrolled in multinational placebo-controlled clinical trial. Shown are adverse events that occurred more frequently in carvedilol-treated patients than placebo-treated patients with an incidence >1% regardless of causality. (See Table 7.)

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In addition to the events in Table 7, when compared with placebo, carvedilol-treated patients had fewer of the following adverse events related to the cardiovascular system and occurring in or equal to 2% of patients: sudden death, atrial fibrillation, chest pain, congestive heart failure, heart failure, peripheral vascular disorder, unstable angina pectoris and ventricular tachycardia. Other adverse experiences occurring in greater or equal to 2% but reported less frequently in carvedilol-treated patients include: abdominal pain, pain in the extremity, hypokalemia, lung edema, pneumonia, abnormal kidney function and urinary tract infection.
Less Common Clinical Trials Adverse Drug Reactions (˂ 1%): Hypertension and Heart Failure - Open and Controlled Trials: The following adverse events were reported as possibly or probably related in worldwide open or controlled trials with carvedilol in patients with hypertension or congestive heart failure at an incidence of > 0.1% to ≤ 1%: Cardiovascular: Peripheral ischemia, tachycardia.
Central and Peripheral Nervous System: Hypokinesia.
General: Substernal chest pain, edema.
Psychiatric: Sleep disorder, aggravated depression, impaired concentration, abnormal thinking, paroniria, emotional lability.
Respiratory System: Asthma.
Reproductive, Male: Decreased libido.
Skin and Appendages: Pruritus, rash erythematous, rash maculopapular, rash psoriaform, photosensitivity reaction.
Special Senses: Tinnitus.
Urinary System: Micturition frequency.
Autonomic Nervous System: Dry mouth, sweating increased.
Metabolic and Nutritional: Diabetes mellitus.
The following adverse events were reported as possibly or probably related in worldwide open or controlled trials with carvedilol in patients with hypertension or congestive heart failure at an incidence of ≤ 0.1%, and are potentially important: complete AV block, bundle branch block, myocardial ischemia, cerebrovascular disorder, convulsions, migraine, neuralgia, paresis, anaphylactoid reaction, alopecia, exfoliative dermatitis, amnesia, GI hemorrhage, bronchospasm, pulmonary edema, decreased hearing, respiratory alkalosis, decreased HDL, pancytopenia, and atypical lymphocytes.
Post-Market Adverse Drug Reactions: Reports of aplastic anemia and severe skin reactions (Stevens-Johnson syndrome, toxic epidermal necrolysis, and erythema multiforme) have been rare and received only when carvedilol was administered concomitantly with other medications associated with such reactions. Urinary incontinence in women (which resolved upon discontinuation of the medication) and interstitial pneumonitis have been reported rarely.

Overview: Inducers and Inhibitors of Cytochrome P450: Since carvedilol undergoes substantial oxidative metabolism, care may be required in patients receiving inducers or inhibitors of cytochrome P450, as plasma concentrations may be altered. Pre-treatment with rifampin (600 mg daily for 12 days) decreased the AUC and C_max for carvedilol approximately 70% following a single oral dose of carvedilol. Co-administration of carvedilol and cimetidine (1000 mg/day) resulted in a 30% increase in median AUC for carvedilol. Despite the reduction in oral clearance, peak plasma concentrations of carvedilol were unchanged due to an apparent decrease in rate of absorption.
Interactions of carvedilol with strong inhibitors of CYP2D6 (such as quinidine, fluoxetine, paroxetine, and propafenone) have not been studied, but these drugs would be expected to increase blood levels of the R(+) enantiomer of carvedilol. Retrospective analysis of side effects in clinical trials showed that poor 2D6 metabolizers had a higher rate of dizziness during up-titration, presumably resulting from vasodilating effects of the higher concentrations of the (alpha)-blocking R(+) enantiomer (see Pharmacology: Pharmacokinetics: Special Populations and Conditions: Genetic Polymorphism under Actions).
Drug-Drug Interactions: Antihypertensive Agents: When administered concomitantly with other drugs that are anti-hypertensive in action or have hypotension as part of their adverse effect profile, carvedilol may have additive effects to excessively lower blood pressure.
Catecholamine-depleting agents: Patients taking both agents with β-blocking properties and a drug that can deplete catecholamines (e.g., reserpine and monoamine oxidase inhibitors) should be observed closely for evidence of hypotension and/or marked bradycardia.
Antiarrhythmics and Calcium Channel Blockers: Isolated cases of conduction disturbance (rarely with hemodynamic compromise) have been observed when carvedilol is co-administered with anti-arrhythmic agents or calcium channel blockers such as diltiazem and verapamil that can slow cardiac conduction. As with other agents with β-blocking properties, if carvedilol is to be administered orally with antiarrhythmics that slow conduction or calcium channel blockers of the verapamil or diltiazem type, it is recommended that ECG and blood pressure be monitored.
Digoxin: Following concomitant administration of carvedilol and digoxin, peak concentration of digoxin increased by approximately 30% and steady-state trough concentrations of digoxin were increased by about 15%. Both digoxin and carvedilol slow AV conduction. Therefore, increased monitoring of digoxin levels is recommended when initiating, adjusting or discontinuing carvedilol.
Clonidine: Concomitant administration of clonidine with agents with beta-blocking properties may potentiate blood pressure and heart rate lowering effects. When concomitant treatment with agents with beta-blocking properties and clonidine is to be terminated, the beta-blocking agent should be discontinued first. Clonidine therapy can then be discontinued several days later by gradually decreasing the dosage.
Cyclosporine: Modest increases in mean trough cyclosporine concentrations were observed following initiation of carvedilol treatment in 21 renal transplant patients suffering from chronic vascular rejection. In about 30% of patients, the dose of cyclosporine had to be reduced in order to maintain cyclosporine concentrations within the therapeutic range, while in the remainder no adjustment was needed. On the average for the group, the dose of cyclosporine was reduced about 20% in these patients. Due to wide inter-individual variability in the dose adjustment required, it is recommended that cyclosporine concentrations be monitored closely after initiation of carvedilol therapy and that the dose of cyclosporine be adjusted as appropriate.
Fingolimod: Concomitant use of fingolimod with beta blockers may potentiate bradycardic effects and is not recommended. Where such co-administration is considered necessary, appropriate monitoring at treatment initiation, i.e. at least overnight monitoring, is recommended.
Nitroglycerin: The effect of carvedilol co-administration with nitroglycerin has not been studied. Carvedilol could blunt the reflex tachycardia produced by nitroglycerin through its beta-adrenergic blocking activity. When it is used with nitroglycerin in patients with angina pectoris, additional decreases in blood pressure may occur.
Insulin or Oral Hypoglycemics: Agents with beta-blocking properties may enhance the blood-sugar reducing effect of insulin and oral hypoglycemics. Therefore, in patients taking insulin or oral hypoglycemics, regular monitoring of blood glucose is recommended.
Tricyclic Antidepressants: The effect of carvedilol co-administration with tricyclic antidepressants has not been studied. As an increased incidence of tremor has been observed with other drugs of this class upon co-administration of tricyclic antidepressants, the possibility of a drug interaction cannot be excluded.
Warfarin: Carvedilol (12.5 mg twice daily for 7 days) did not have an effect on warfarin-induced increase in steady-state prothrombin time ratios and did not alter the pharmacokinetics of both enantiomers of warfarin following concomitant administration with warfarin in healthy volunteers.
Drug-Food Interactions: Grapefruit Juice: Following simultaneous administration of a single dose of 25 mg of carvedilol with 300 mL of grapefruit juice (an inhibitor of CYP3A4 and CYP1A2), AUC for carvedilol was approximately 16% higher than following administration of carvedilol with 300 mL of water.
Drug-Herb Interactions: Interactions with herbal products have not been established.
Drug-Laboratory Test Interactions: Interactions with laboratory tests have not been established.

pms-CARVEDILOL tablets should be stored at room temperature, between 15°C and 30°C, in tightly closed containers or dispensed in a tight, light-resistant container. Protect from high humidity.
Since the tablets discolor when exposed to light, they should be kept in light resistant container.

Beta-Blockers

C07AG02 - carvedilol ; Belongs to the class of alpha and beta blocking agents. Used in the treatment of cardiovascular diseases.

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