Unisia

Candesartan cilexetil, amlodipine.

Each tablet contains candesartan cilexetil 8 mg and amlodipine 5 mg equivalent to amlodipine besilate 6.93 mg.
Candesartan cilexetil: Candesartan cilexetil is (1RS)-1-(Cyclohexyloxycarbonyloxy)ethyl 2-ethoxy-1-{[2'-(H-tetrazol-5-yl)biphenyl-4-yl]methyl}-1H-benzo[d]imidazole-7-carboxylate.
It has a molecular formula of C₃₃H₃₄N₆O₆ and a molecular weight of 610.66.
Candesartan cilexetil occurs as white crystals or crystalline powder. It is soluble in acetic acid (100), sparingly soluble in methanol, slightly soluble in ethanol (99.5), and practically insoluble in water. A solution of Candesartan cilexetil in methanol (1 in 100) shows no optical rotation.
Amlodipine besilate: Amlodipine besilate is 3-Ethyl 5-methyl (4RS)-2-[(2-aminoethoxy) methyl]-4-(2-chlorophenyl)-6-methyl-1,4-dihydropyridine-3,5-dicarboxylate monobenzenesulfonate.
It has a molecular formula of C₂₀H₂₅ClN₂O₅ • C₆H₆O₃S and a molecular weight of 567.05.
Amlodipine besilate occurs as white to yellowish crystalline powder. It is freely soluble in methanol, sparingly soluble in ethanol (99.5), and slightly soluble in water. A solution of amlodipine in methanol (1 in 100) shows no optical rotation.

Pharmacology: Pharmacodynamics: Mechanism of Antihypertensive Action: In the absorption process in the body, candesartan cilexetil is rapidly hydrolyzed to the active metabolite candesartan, which exerts its antihypertensive action primarily by inhibiting the potent vasoconstrictor effect of angiotensin II through its antagonistic action at the angiotensin II type 1 (AT₁) receptor in vascular smooth muscle, thereby reducing peripheral vascular resistance. In addition, inhibitory effect on the release of aldosterone from adrenal gland mediated by AT₁ receptor is considered to play a role in the antihypertensive action. Amlodipine besilate acts as a dihydropyridine calcium channel antagonist, and is characterized by gradual onset of action and continuous effect.
Dihydropyridine calcium channel antagonist selectively binds to the membrane potential-dependent L-type calcium channels and reduces calcium influx into cells, causing relaxation of coronary or peripheral vascular smooth muscle.
Effect on the Renin-Angiotensin System: When candesartan cilexetil was administered repeatedly at a once daily dose of 1-12 mg to 74 hypertensive patients (56 with essential hypertension, 18 with hypertension accompanied by renal dysfunction), plasma renin activity and the plasma levels of angiotensin I and II were elevated.
Clinical Studies: The result of double blind comparative study in patients with essential hypertension where a once daily dose of 8 mg/5 mg, 8 mg/2.5 mg, 8 mg/0 mg, or 0 mg/5 mg of candesartan cilexetil/amlodipine was administered for 12 weeks is as follows.
Significant differences in sitting diastolic blood pressure at trough and sitting systolic blood pressure at trough were observed in 8 mg/5 mg group compared to both 8 mg/0 mg and 0 mg/5 mg groups and in 8 mg/2.5 mg group compared to 8 mg/0 mg group (see Table 1).

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In the long-term study (52 weeks) of concomitant use of candesartan cilexetil and amlodipine besilate, hypotensive effect persisted, the effect did not decrease, and stable control of blood pressure was obtained.
Once daily without setting the administration timing, before or after meals (see Pharmacokinetics).
Pharmacokinetics: Blood Concentration: After a single oral administration of a candesartan cilexetil/amlodipine 8 mg/5 mg combination tablet to healthy adults, active metabolite candesartan and inactive metabolite M-II and unchanged amlodipine were detected in the blood, but the unchanged candesartan cilexetil was undetected. Changes of blood concentrations of active metabolite candesartan and amlodipine are as indicated in Figures 1 and 2 and in Table 2. (See Figures 1 and 2, Table 2.)

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Effect of Meals: When a candesartan cilexetil/amlodipine 8 mg/5 mg combination tablet was administered to 12 healthy adults after meal, the C_max of active metabolite candesartan were about 2.1 times higher (under fasting: 78.9 ng/mL, after meal: 160.0 ng/mL) and the C_max of active metabolite candesartan were about 1.2 times higher (under fasting: 1,171.1 ng·hr/mL, after meal: 1,286.7 ng·hr/mL) than those under fasting conditions. No changes were observed in the C_max and AUC of amlodipine.
Bioequivalence: When the administration of a candesartan cilexetil/amlodipine 8 mg/5 mg combination tablet to healthy adults was compared with the concomitant use of each components, the bioequivalency of each components was confirmed both under fasting conditions or after meals. C_max and AUC of each component under fasting conditions or after meals are as indicated in Tables 3 and 4. (See Tables 3 and 4.)

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Urinary Excretion: After a single oral administration of a candesartan cilexetil/amlodipine 8 mg/5 mg combination tablet to 12 healthy adults, unchanged candesartan cilexetil was not detected in the urine, but the active metabolite candesartan, inactive metabolite M-II and unchanged amlodipine were excreted in the urine. The 48-hr cumulative excretion rates in the urine were 11.9% for candesartan and M-II combined, and 4.8% for unchanged amlodipine.
Metabolism: Candesartan cilexetil is metabolized to an active metabolite candesartan by carboxylesterase, and a part of it is further metabolized to inactive metabolite M-II by CYP2C9. However, compared with the blood concentration and urinary excretion of candesartan, those of M-II after administration of this drug to patients with essential hypertension are lower, indicating that the influence of genetic polymorphism of CYP2C9 on the blood concentration of candesartan is negligible.
Candesartan does not inhibit the metabolic activity of CYP1A1, 1A2, 2A6, 2B6, 2C8, 2C9-Arg, 2C19, 2D6, 2E1 and 3A4 (in vitro).
Amlodipine is mainly metabolized by CYP3A4, and unchanged component as well as 9 metabolites are detected in the urine.
Population Pharmacokinetics (PPK) Analysis Using Blood Candesartan Concentration Levels: 2,886 time point samples of blood candesartan concentration obtained from total of 224 cases - 168 healthy male adults, 30 patients with essential hypertension and elderly essential hypertension, 18 hypertensive patients with renal dysfunction and 8 hypertensive patients with hepatic dysfunction were used to study relationship between sex/age/bodyweight/hepatic function parameter [AST (GOT), ALT (GPT)]/renal function parameter (serum creatinine, BUN)/blood albumin level/existence of hypertension and candesartan clearance/distribution volume/relative bioavailability. It is suggested that clearance in patients with hepatic dysfunction [AST (GOT) >40 or ALT (GPT) >35] decreases by 45%.

Hypertension.
Precaution for Indication: Since this drug may cause excessively decreased blood pressure etc., do not use this drug as a primary drug for the treatment of hypertension.

Adults: 1 tablet once daily. Do not use this drug as a primary drug for treatment of hypertension.
Precaution: Dosage should be determined for each patient based on the following dosage and administration of candesartan cilexetil and amlodipine besilate.
Candesartan Cilexetil: Hypertension: Adults: 4-8 mg once daily. The dosage may be increased up to 12 mg, if necessary.
Renal Dysfunction: Starting Dose: 2 mg once daily, may be increased up to 8 mg, if necessary.
Amlodipine Besilate: Hypertension: Adults: 2.5-5 mg once daily. The dosage may be appropriately adjusted according to the patient's symptoms, and dose can be increased up to 10 mg once daily when the effect is insufficient.
In principle, switching to Unisia tablets should be considered when candesartan cilexetil 8 mg and amlodipine 2.5-5 mg are co-administered, or when the blood pressure is not controlled sufficiently by administration of one of them.

Symptoms: Overdose of Unisia tablets may cause marked decrease in blood pressure, including shock and reflex tachycardia.
Treatment: Cardiac and respiratory function should be monitored and blood pressure should be measured frequently. If marked decrease in blood pressure occur, provide cardiovascular support including elevation of the extremities and the administration of fluids. If the symptom does not improve, administration of vasopressors should be considered with careful attention to circulating blood volume and urine output. Since candesartan and amlodipine, components of Unisia have high protein-binding rates, hemodialysis is not effective for elimination. Charcoal administration is reported to be effective for inhibition of absorption since AUC of amlodipine is decreased by 99% and 49% when activated charcoal was administered immediately after the use of amlodipine and 2 hrs after the use of amlodipine, respectively.

Patients with a history of hypersensitivity to candesartan cilexetil, amlodipine besilate, dihydropyridines or any of the excipients of Unisia.
Pregnant women or women having possibilities of being pregnant. (See Use in Pregnancy & Lactation.)

Careful Administration: Unisia tablets should be administered with care in the following patients: Patients with bilateral or unilateral renal artery stenosis (Candesartan cilexetil may aggravate renal function.); patients with renal dysfunction (Renal function may be aggravated by excessive decrease in blood pressure.); patients with hyperkalemia (Candesartan cilexetil may aggravate hyperkalemia.); patients with hepatic dysfunction [Candesartan cilexetil may aggravate hepatic function, and decrease in clearance of candesartan active metabolite is anticipated (see Pharmacology: Pharmacokinetics under Actions); since amlodipine besilate is mainly metabolized in the liver, blood concentration half-life may prolong and area under the blood concentration-time curve (AUC) may increase in the patients with hepatic dysfunction.]; patients with a history of drug hypersensitivity; elderly patients (see Use in Elderly).
Unisia is a combination of candesartan cilexetil 8 mg and amlodipine 5 mg. Since adverse reactions by both candesartan cilexetil and amlodipine besilate may occur, the use of Unisia should be considered appropriately.
Since candesartan cilexetil may rapidly deteriorate renal function in patients with bilateral or unilateral artery stenosis due to a decrease in renal blood flow and/or glomerular filtration pressure, administration of Unisia should be avoided unless it is considered therapeutically essential.
Since candesartan cilexetil may aggravate hyperkalemia in patients with hyperkalemia, administration of Unisia should be avoided unless it is considered therapeutically essential.
Additionally, since hyperkalemia may occur in patients whose serum potassium level is liable to increase due to renal dysfunction or uncontrolled diabetes mellitus, caution should be paid to serum potassium levels.
Candesartan cilexetil may rarely cause a sudden fall in blood pressure, resulting in shock, syncope, transient unconsciousness or renal hypofunction. Therefore, blood pressure, renal function and the patient's condition should be closely observed during administration of Unisia, especially to the following patients: Patients on hemodialysis, strict dietary salt restriction and diuretic therapy (especially patients who have recently started diuretic therapy); patients with hyponatremia, renal dysfunction and heart failure.
It is recommended not to administer Unisia within 24 hr before surgery. (Patients on angiotensin II receptor antagonist may develop a severe fall in blood pressure during anesthesia and surgery due to inhibitory action on renin-angiotensin system.)
Mild hypotensive effect remains after the termination of the administration of amlodipine besilate due to its long blood concentration half-life. Therefore, when using other antihypertensive after the termination of the administration of Unisia, patient's condition should be closely observed eg, paying attention to dosage and intervals of administration.
Precautions Concerning Use: When Dispensing the Drug: The patient must be instructed to remove the tablets from the press-through package (PTP) before they are ingested. [It has been reported that, if the PTP sheet is swallowed, the sharp corners of the sheet may puncture the esophageal mucosa, and this could result in serious complications such as mediastinitis.]
Although the causal relationship has not been established, myocardial infarction and arrhythmia (including ventricular tachycardia) were reported during the administration of amlodipine besilate.
Effects on the Ability to Drive or Operate Machinery: Since dizziness and lightheadedness may occur due to antihypertensive action of Unisia, patients should be cautioned against engaging in operation of machinery involving risk eg, working at a height, and driving motor vehicles.
Use in Children: The safety of Unisia in low birth weight infants, neonates, nursing infants, infants and children has not been established (no clinical experience).
Use in Elderly: Unisia should be administered carefully while closely observing the patient's condition with attention to following points: It is generally acknowledged that an excessive fall of blood pressure should be avoided in the elderly (cerebral infarction may occur). In the pharmacokinetics study of amlodipine besilate in the elderly, tendency of higher blood concentration and longer half-life were observed. Therefore, Unisia tablets should be administered carefully, taking such measures as starting with a lower dose.

Use in Pregnancy: Unisia tablets should not be administered to pregnant women or women having possibilities of being pregnant. If pregnancy is detected during treatment, this drug should be discontinued immediately.
In patients with hypertension who were given angiotensin II receptor antagonists including candesartan cilexetil or angiotensin-converting enzyme inhibitors in the 2nd and 3rd trimesters of pregnancy, it has been reported that oligohydramnios, fetal and neonatal death, neonatal hypotension, renal failure, hyperkalemia, cranial hypoplasia and the following events those are supposed to be due to oligohydramnios, cranial hypoplasia, limb contractures, craniofacial deformation and lung hypoplasia occurred.
It has been reported that gestation period and duration of delivery are prolonged when amlodipine besilate is administered in the 3rd trimester of pregnancy in animal studies.
Use in Lactation: Unisia tablets should not be administered to nursing mothers. If indispensable, however, the patients should be instructed to discontinue lactation.
Oral administration of candesartan cilexetil to rats during the perinatal and lactation periods by gavage at ≥10 mg/kg/day produced an increased incidence of neonatal hydronephrosis. Administration of candesartan cilexetil to rats only during the 3rd trimester of pregnancy or during the lactation period at 300 mg/kg/day also resulted in an increased incidence of neonatal hydronephrosis.
It has been reported that amlodipine besilate transfers to mother's milk in animal studies.

Adverse reactions to Unisia, including abnormalities in laboratory data, were observed in 35 (11.6%) of 302 patients in the clinical study before approval.
Following adverse reactions were observed in either in the previously mentioned study or spontaneous reports of candesartan cilexetil or amlodipine besilate, and so on. If any adverse reaction is observed, appropriate measures should be taken eg, discontinuation of Unisia.
Clinically Significant Adverse Reactions (Frequency Unknown): Angioedema: Since angioedema manifested by facial, labial, glossal and laryngopharyngeal swellings may occur, patients should be closely observed. If any abnormality is observed, Unisia tablets should be discontinued, and appropriate measures taken.
Shock, Syncope or Unconsciousness: Since shock, syncope or unconsciousness due to lowering of blood pressure may occur, close observation should be made. If coldness, vomiting, unconsciousness are observed, appropriate measures should be taken immediately. Condition of the patients should be closely observed during administration of Unisia tablets, especially in patients on hemodialysis, those on strict dietary salt restriction, those under diuretic therapy, and those with heart failure.
Acute Renal Failure: Since acute renal failure may occur, patients should be closely observed. If any abnormality is observed, Unisia tablets should be discontinued, and appropriate measures taken.
Hyperkalemia: Since severe hyperkalemia may occur, patients should be closely observed. If any abnormality is observed, appropriate measures should immediately be taken.
Hepatic Dysfunction or Jaundice: Since hepatic dysfunction, including increased AST (GOT), ALT (GPT), γ-GTP or jaundice may occur, patients should be closely observed. If any abnormality is observed, Unisia should be discontinued, and appropriate measures taken.
Agranulocytosis, Decreased White Blood Cell: Since agranulocytosis and decreased white blood cell may occur, patients should be closely observed. If any abnormality is observed, Unisia tablets should be discontinued, and appropriate measures taken.
Rhabdomyolysis: Since rhabdomyolysis, which is characterized by muscle ache, weakness, increased CK (CPK), and increased blood and urinary myoglobin, may occur, patient should be closely observed. In such a case, administration of Unisia should be immediately discontinued, and appropriate measures taken.
Interstitial Pneumonia: Interstitial pneumonia with fever, coughing, dyspnea, abnormal chest X-ray may occur. In such a case, Unisia should be discontinued and appropriate measures eg, treatment with an adrenocortical hormone, should be taken.
Hypoglycemia: Since hypoglycemia may occur (liable to occur in patients on diabetic therapy), close observation should be made. If feeling of weakness or hunger, cold sweat, tremor of hands, decreased mental concentration, convulsions, disturbed consciousness are observed, Unisia should be discontinued, and appropriate measures taken.
Decreased Platelet Count: Since decreased platelet count may occur, patients should be closely observed. If any abnormality is observed, Unisia tablets should be discontinued, and appropriate measures taken.
Atrioventricular Block: Since atrioventricular block (initial symptoms: Bradycardia, dizziness) may occur, patients should be closely observed. If any abnormality is observed, Unisia tablets should be discontinued, and appropriate measures taken.
Other Adverse Reactions: (See Table 5).

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It is considered that enzyme CYP3A4 mainly contributes to amlodipine metabolism.
Precautions for Co-Administration: Unisia tablets should be administered with care when co-administered with the following drugs: (see Table 6).

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Store below 30°C.

Angiotensin II Antagonists

C09DB07 - candesartan and amlodipine ; Belongs to the class of angiotensin II receptor blockers (ARBs) and calcium channel blockers. Used in the treatment of cardiovascular disease.

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