Adalat GITS 30

Adalat GITS 30

nifedipine

Manufacturer:

Bayer

Distributor:

Zuellig
Full Prescribing Info
Contents
Nifedipine.
Description
Adalat GITS prolonged-release tablet also contains the following inactive ingredients: Hypromellose, polyethylene oxide, magnesium stearate, sodium chloride, red iron oxide (E172/CI 77491), cellulose acetate, polyethylene glycol 3350, hydroxypropyl cellulose, propylene glycol, titanium dioxide (E171/CI 77891).
Action
Antianginal/Antihypertensive.
Nifedipine is a calcium antagonist of the 1,4-dihydropyridine type. Calcium antagonists reduce the transmembrane influx of calcium ions through the slow calcium channel into the cell. Nifedipine acts particularly on the cells of the myocardium and the smooth muscle cells of the coronary arteries and the peripheral resistance vessels.
In the heart, nifedipine dilates the coronary arteries, especially the large conductance vessels, even in the free wall segment of partially stenosed areas. Further, nifedipine reduces the vascular smooth muscle tone in the coronary arteries and prevents vasospasm. The end-result is an increased post-stenotic blood flow and an increased oxygen supply. Parallel to this, nifedipine reduces the oxygen requirement by lowering peripheral resistance (afterload). With long-term use, nifedipine can also prevent the development of new atherosclerotic lesions in the coronary arteries.
Nifedipine reduces the smooth muscle tone of the arterioles, thus lowering the increased peripheral resistance and consequently, the blood pressure. At the beginning of the nifedipine treatment, there may be a transient reflex increase in heart rate, and thus in the cardiac output. However, this increase is not enough to compensate for the vasodilation. In addition, nifedipine increases sodium and water excretion both in the short- and long-term use. The blood pressure-lowering effect of nifedipine is particularly pronounced in hypertensive patients.
Adalat GITS 30 tablets are formulated to provide nifedipine at an approximately constant rate over 24 hrs. Nifedipine is released from the tablet at a zero-order rate by a membrane-controlled, osmotic push-pull process. The delivery rate is independent of gastrointestinal pH or motility. Upon swallowing, the biologically inert components of the tablet remain intact during gastrointestinal transit and are eliminated in the feces as an insoluble shell.
Indications/Uses
Treatment of coronary heart disease: Chronic stable angina pectoris (angina of effort).
Treatment of hypertension.
Dosage/Direction for Use
As much as possible, the treatment must be tailored to the needs of the individual.
Depending on the clinical picture in each case, the basic dose must be introduced gradually. In patients with impaired liver function, careful monitoring and, in severe cases, a dose reduction may be necessary.
Unless otherwise prescribed, the following dosage guidelines are recommended for adults.
Coronary Heart Disease: Chronic Stable Angina Pectoris (angina of effort): 1 Adalat GITS 30 tab once daily (1 x 20 mg/day, 1 x 30 mg/day or 1 x 60 mg/day).
Hypertension: 1 Adalat GITS 30 tab once daily (1 x 20 mg/day, 1 x 30 mg/day or 1 x 60 mg/day).
A starting dose of 20 mg once daily may be considered when medically indicated. In general, therapy should be initiated with 30 mg once daily. Interim doses ie, 40 mg, 50 mg, etc, can be applied by combinations of, ie 20-mg + 20-mg or 20-mg + 30-mg tabs.
Depending on the severity of the disease and the patient's response, the dose can be increased in stages to 120 mg once daily.
As a rule, the tablets are swallowed whole with a little liquid, independently of meals. The tablets must not be chewed or broken up. The attending doctor will determine the duration of use.
Overdosage
Symptoms: The following symptoms are observed in cases of severe nifedipine intoxication: Disturbances of consciousness to the point of coma, a drop in blood pressure, tachycardiac/bradycardiac heart rhythm disturbances, hyperglycemia, metabolic acidosis, hypoxia, cardiogenic shock with pulmonary edema.
Treatment: As far as treatment is concerned, elimination of the active substance and the restoration of stable cardiovascular conditions have priority.
After oral ingestion, thorough gastric lavage is indicated, if necessary, in combination with irrigation of the small intestine. Particularly, in cases of intoxication with slow-release products eg, Adalat GITS 30, elimination must be as complete as possible, including the small intestine to prevent the otherwise inevitable subsequent absorption of the active substance.
Hemodialysis serves no purpose as nifedipine is not dialyzable, but plasmapheresis is advisable (high plasma protein-binding, relatively low volume of distribution).
Bradycardiac heart rhythm disturbances may be treated symptomatically with β-sympathomimetics, and in life-threatening bradycardiac disturbances of heart rhythm, temporary pacemaker therapy can be advisable.
Hypotension as a result of cardiogenic shock and arterial vasodilation can be treated with calcium (10-20 mL of a 10% calcium gluconate solution administered slowly IV and repeated if necessary). As a result, the serum calcium can reach the upper normal range to slightly elevated levels. If an insufficient increase in blood pressure is achieved with calcium, vasoconstricting sympathomimetics eg, dopamine or noradrenaline are additionally administered. The dosage of these drugs is determined solely by the effect obtained.
Additional liquid or volume must be administered with caution because of the danger of overloading the heart.
Contraindications
Known hypersensitivity to nifedipine. Cardiovascular shock. Patients with Kock pouch (ileostomy after proctocolectomy). Pregnancy before week 20 and during breastfeeding.
Nifedipine must not be used in combination with rifampicin because no efficient plasma levels of nifedipine may be obtained due to enzyme induction.
In vitro Fertilization: In single cases of in vitro fertilization, calcium antagonists like nifedipine have been associated with reversible biochemical changes in the spermatozoa's head section that may result in impaired sperm function. In those men who are repeatedly unsuccessful in fathering a child by in vitro fertilization, and where no other explanation can be found, calcium antagonists like nifedipine should be considered as possible causes.
Use in pregnancy: Nifedipine is contraindicated in pregnancy before week 20. There are no adequate and well controlled studies in pregnant women. In animal studies nifedipine has been shown to produce embryotoxicity, fetotoxicity and teratogenicity.
Use in lactation: Nifedipine passes into the breast milk. As there is no experience of possible effects on infants, breastfeeding should first be stopped if nifedipine treatment becomes necessary during breastfeeding period.
Special Precautions
Care must be exercised in patients with very low blood pressure (severe hypotension with systolic pressure <90 mm Hg), in cases of manifest heart failure and in the case of severe aortic stenosis.
Careful monitoring of blood pressure must be exercised, also when administering nifedipine with IV magnesium sulfate, owing to the possibility of an excessive fall in blood pressure which could harm both mother and fetus.
As with other nondeformable material, care should be used when administering Adalat GITS 30 in patients with preexisting severe gastrointestinal narrowing because obstructive symptoms may occur.
Bezoars can occur in very rare cases and may require surgical intervention.
In single cases obstructive symptoms have been described without known history of gastrointestinal disorders.
When doing barium contrast x-ray, Adalat GITS may cause false positive effects (eg, filling defects interpreted as polyp).
In patients with impaired liver function, careful monitoring and, in severe cases, a dose reduction may be necessary.
Effects on the Ability to Drive or Operate Machinery: Reactions to the drug, which vary in intensity from individual to individual, can impair the ability to drive or to operate machinery. This applies particularly at the start of treatment, on changing the medication and in combination with alcohol.
Use In Pregnancy & Lactation
Use in Pregnancy: Nifedipine is contraindicated in pregnancy before week 20. There are no adequate and well controlled studies in pregnant women. In animal studies nifedipine has been shown to produce embryotoxicity, fetotoxicity and teratogenicity.
Use in Lactation: Nifedipine passes into the breast milk. As there is no experience of possible effects on infants, breastfeeding should first be stopped if nifedipine treatment becomes necessary during breastfeeding period.
Adverse Reactions
Adverse drug reactions (ADRs) based on placebo-controlled studies with nifedipine sorted by CIOMS III categories of frequency (clinical trial database: nifedipine n=2661; placebo n=1486; status: February 22, 2006 and the ACTION study: nifedipine n=3825; placebo n=3840) are listed as follows:
ADRs listed under "common" were observed with a frequency below 3% with the exception of edema (9.9%) and headache (3.9%).
The frequencies of ADRs reported with nifedipine containing products are summarized in the following texts. Within each frequency grouping, undesirable effects are presented in order of decreasing seriousness. Frequencies are defined as common (≥1/100 to <1/10), uncommon (≥1/1000 to <1/100) and rare (≥1/10,000 to <1/1000). The ADRs identified only during the ongoing post-marketing surveillance, and for which a frequency could not be estimated, are listed under "not known".
System Organ Class (MedDRA): Blood and Lymphatic System Disorders: Not known: Agranulocytosis, leukopenia.
Immune System Disorders: Uncommon: Allergic reaction, allergic edema/angioedema (including larynx edema which may result in life-threatening outcome). Rare: Pruritus, urticaria, rash. Not known: Anaphylactic/anaphylactoid reaction.
Psychiatric Disorders: Uncommon: Anxiety reactions, sleep disorders.
Metabolism and Nutrition Disorders: Not known: Hyperglycemia.
Nervous System Disorders: Common: Headache. Uncommon: Vertigo, migraine, dizziness, tremor. Rare: Paresthesia, dysesthesia. Not known: Hypoesthesia, somnolence.
Eye Disorders: Uncommon: Visual disturbances. Not known: Eye pain.
Cardiac Disorders: Uncommon: Tachycardia, palpitations. Not known: Chest pain (angina pectoris).
Vascular Disorders: Common: Edema, vasodilatation. Uncommon: Hypotension, syncope.
Respiratory, Thoracic and Mediastinal Disorders: Uncommon: Nosebleed, nasal congestion. Not known: Dyspnea.
Gastrointestinal Disorders: Common: Constipation. Uncommon: Gastrointestinal and abdominal pain, nausea, dyspepsia, flatulence, dry mouth. Rare: Gingival hyperplasia. Not known: Bezoar, dysphagia, intestinal obstruction, intestinal ulcer, vomiting, gastroesophageal sphincter insufficiency.
Hepatobiliary Disorders: Uncommon: Transient increase in liver enzymes. Not known: Jaundice.
Skin and Subcutaneous Tissue Disorders: Uncommon: Erythema. Not known: Toxic epidermal necrolysis, photosensitivity allergic reaction, palpable purpura.
Musculoskeletal and Connective Tissue Disorders: Uncommon: Muscle cramps, joint swelling. Not known: Arthralgia, myalgia.
Renal and Urinary Disorders: Uncommon: Polyuria, dysuria.
Reproductive System and Breast Disorders: Uncommon: Erectile dysfunction.
General Disorders and Administration Site Conditions: Common: Feeling unwell. Uncommon: Unspecific pain, chills.
In dialysis patients with malignant hypertension and hypovolemia a distinct fall in blood pressure can occur as a result of vasodilation.
Drug Interactions
The blood pressure-lowering effect of nifedipine may be potentiated upon co-administration of other antihypertensive drugs.
When nifedipine is administered simultaneously with β-receptor blockers, the patient should be carefully monitored since fairly severe hypotension can occur. Deterioration of heart failure is also known to develop in isolated cases.
Nifedipine is metabolized via the cytochrome P-450 3A4 system, located both in the intestinal mucosa and in liver. Drugs that are known to either inhibit or induce this enzyme system may therefore alter the first-pass (after oral administration) or the clearance of nifedipine.
Digoxin: The simultaneous administration of nifedipine and digoxin may lead to reduced digoxin clearance and hence, an increase in plasma concentrations of digoxin. The patient should therefore be checked for symptoms of digoxin overdosage as a precaution and, if necessary, the glycoside dose should be reduced, taking account of the plasma concentration of digoxin.
Cytochrome P-450 3A4 System-Inducing Antiepileptic Drugs, eg Phenytoin, Carbamazepine and Phenobarbitone: Phenytoin induces the cytochrome P-450 3A4 system. Upon co-administration with phenytoin, the bioavailability of nifedipine is reduced and thus its efficacy weakened. When both drugs are concomitantly administered, the clinical response to nifedipine should be monitored and, if necessary, an increase of the nifedipine dose considered. If the dose of nifedipine is increased during co-administration of both drugs, a reduction of the nifedipine dose should be considered when the treatment with phenytoin is discontinued.
No formal studies have been performed to investigate the potential interaction between nifedipine and carbamazepine or phenobarbitone. As both drugs have been shown to reduce the plasma concentrations of the structurally similar calcium channel blocker nimodipine due to enzyme induction, a decrease in nifedipine plasma concentrations and hence a decrease in efficacy cannot be excluded.
Quinidine: When nifedipine and quinidine have been administered simultaneously, lowered quinidine levels or, after discontinuance of nifedipine, a distinct increase in plasma concentrations of quinidine have been observed in individual cases. For this reason, when nifedipine is either additionally administered or discontinued, monitoring of the quinidine plasma concentration and, if necessary, adjustment of the quinidine dose are recommended.
Some authors reported increased plasma concentrations of nifedipine upon co-administration of both drugs, while others did not observe an alteration in the pharmacokinetics of nifedipine. Therefore, the blood pressure should be carefully monitored if quinidine is added to an existing therapy with nifedipine. If necessary, the dose of nifedipine should be decreased.
Quinupristin/Dalfopristin: Simultaneous administration of quinupristin/dalfopristin and nifedipine may lead to increased plasma concentrations of nifedipine. Upon co-administration of both drugs, the blood pressure should be monitored and, if necessary, a reduction of the nifedipine dose is considered.
Cimetidine: Due to its inhibition of cytochrome P-450 3A4, cimetidine elevates the plasma concentrations of nifedipine and may potentiate the antihypertensive effect.
Rifampicin: Strongly induces the cytochrome P-450 3A4 system. Upon co-administration with rifampicin, the bioavailability of nifedipine is distinctly reduced and thus its efficacy is weakened. The use of nifedipine in combination with rifampicin is therefore contraindicated.
Diltiazem: Decreases the clearance of nifedipine. The combination of both drugs should be administered with caution and a reduction of the nifedipine dose may be considered.
Grapefruit Juice: Inhibits the cytochrome P-450 3A4 system. Administration of nifedipine together with grapefruit juice thus results in elevated plasma concentrations of nifedipine due to an increase in drug bioavailability. As a consequence, the blood pressure-lowering effect may be increased.
Cisapride: Simultaneous administration of cisapride and nifedipine may lead to increased plasma concentrations of nifedipine. Upon co-administration of both drugs, the blood pressure should be monitored and, if necessary, a reduction of the nifedipine dose is considered.
Anti-HIV Protease Inhibitors (eg, Ritonavir): A clinical study investigating the potential of a drug interaction between nifedipine and certain anti-HIV protease inhibitors has not yet been performed. Drugs of this class are known to inhibit the cytochrome P-450 3A4 system. In addition, drugs of this class have been shown to inhibit in vitro the cytochrome P-450 3A4 mediated metabolism of nifedipine. When administered together with nifedipine, a substantial increase in plasma concentrations of nifedipine due to a decreased first pass metabolism and a decreased elimination cannot be excluded.
Fluoxetine: A clinical study investigating the potential of a drug interaction between nifedipine and fluoxetine has not yet been performed. Fluoxetine has been shown to inhibit in vitro the cytochrome P-450 3A4 mediated metabolism of nifedipine. Therefore an increase of nifedipine plasma concentrations upon co-administration of both drugs cannot be excluded.
Nefazodone: A clinical study investigating the potential of a drug interaction between nifedipine and nefazodone has not yet been performed. Nefazodone is known to inhibit the cytochrome P-450 3A4 mediated metabolism of other drugs. Therefore an increase of nifedipine plasma concentrations upon co-administration of both drugs cannot be excluded.
Macrolide Antibiotics (eg, Erythromycin): No interaction studies have been carried out between nifedipine and macrolide antibiotics. Certain macrolide antibiotics are known to inhibit the cytochrome P-450 3A4 mediated metabolism of other drugs. Therefore the potential for an increase of nifedipine plasma concentrations upon co-administration of both drugs cannot be excluded.
Azithromycin, although structurally related to the class of macrolide antibiotics is void of CYP3A4 inhibition.
Azole Antimycotics (eg, Ketoconazole): A formal interaction study investigating the potential of a drug interaction between nifedipine and ketoconazole, itraconazole or fluconazole has not yet been performed. Drugs of this class are known to inhibit the cytochrome P-450 3A4 system. When administered orally together with nifedipine, a substantial increase in systemic bioavailability of nifedipine due to an increased absorption cannot be excluded. Upon co-administration, the blood pressure should be monitored and, if necessary, a reduction in the nifedipine dose is considered.
Tacrolimus: It has been shown to be metabolized via the cytochrome P-450 3A4 system. Data recently published indicate that the dose of nifedipine administered simultaneously with tacrolimus may be reduced in individual cases. Upon co-administration of both drugs, the tacrolimus plasma concentration should be monitored and, if necessary, a reduction in the tacrolimus dose is considered.
Valproic Acid: No formal studies have been performed to investigate the potential interaction between nifedipine and valproic acid. As valproic acid has been shown to increase the plasma concentrations of the structurally similar calcium-channel blocker nimodipine due to enzyme inhibition, an increase in nifedipine plasma concentrations and hence an increase in efficacy cannot be excluded.
Other Forms of Interaction: Nifedipine may cause falsely increased spectrophotometric values of urinary vanillyl-mandelic acid. However, measurement with HPLC is unaffected.
Incompatibilities: None.
Caution For Usage
In Adalat GITS, the medication is contained within a nonabsorbable shell that slowly releases the drug for the body to absorb. When this process is completed, the empty tablet is eliminated from the body and may be noticed in the stool.
The light-sensitive active substance contained in Adalat GITS is protected from light inside and outside its packaging. The tablets must be protected from humidity and must therefore only be removed from the foil immediately before use.
Storage
Store at temperatures not exceeding 30°C.
MIMS Class
Calcium Antagonists / Anti-Anginal Drugs / Cardiac Drugs
ATC Classification
C08CA05 - nifedipine ; Belongs to the class of dihydropyridine derivative selective calcium-channel blockers with mainly vascular effects. Used in the treatment of cardiovascular diseases.
Presentation/Packing
Form
Adalat GITS 30 PR tab 30 mg
Packing/Price
30's
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