Each 5- and 10-mg tablet contains amlodipine besylate equivalent to amlodipine 5 mg and 10 mg, respectively.
Long-acting calcium-channel blocker.
Pharmacology: Amlodipine is a dihydropyridine calcium antagonist that inhibits the transmembrane influx of calcium ions into the vascular smooth muscle and cardiac muscle. The mechanism of the antihypertensive action is due to a direct relaxant effect on vascular smooth muscle. The precise mechanism by which amlodipine relieves angina may be due to the following 2 actions: Amlodipine dilates peripheral arterioles thus, reduces the total peripheral resistance against which the heart works. Since there is no associated reflex tachycardia, this unloading of the heart reduces myocardial energy consumption and oxygen requirements and probably accounts for the effectiveness of amlodipine in myocardial ischaemia.
The mechanism of action of amlodipine probably involves dilation of the main coronary arteries and coronary arterioles, both in normal and ischaemic regions.
Pharmacokinetics: After oral administration of the therapeutic doses, amlodipine is well absorbed with peak blood levels between 6-12 hrs post-dose. The volume of distribution was approximately 20 L/kg. The terminal elimination half-life is about 35-50 hrs and is consistent with once-daily dosing, steady-state plasma levels are reached after 7-8 days of consecutive dosing. Amlodipine is extensively metabolised to inactive metabolite with 10% of the parent compound and 60% of metabolites excreted in the urine. Bioavailability following oral administration approximates 60-65%. Approximately 97.5% of amlodipine is bound to plasma proteins.
Treatment of hypertension and myocardial ischaemia associated with angina pectoris.
Adults: Hypertension and Angina: Recommended Initial Dose: 5 mg orally once daily which may be increased to a maximum dose of 10 mg depending on the individual patient's response. The dose does not need adjusting when amlodipine is given concurrently with thiazide diuretics, β-adrenoreceptor-blocking agents or angiotensin-converting enzyme inhibitors. Amlodipine can be administered with or without food.
Elderly: Although elderly patients may have higher plasma concentration of amlodipine than younger patients, the terminal elimination half-lives are similar. Amlodipine is similarly well tolerated in elderly or younger patients. Therefore, normal dosage is recommended.
Renal Impairment: Changes in amlodipine plasma concentration are not correlated with the degree of renal impairment, therefore, the normal dosage is recommended. Amlodipine is not dialysable.
Patients with Impaired Hepatic Function: The half-life of amlodipine in patients with impaired liver function and dosage recommendation has not been established. Amlodipine should therefore be administered with caution in these patients.
There is no well-documented experience with amlodipine overdosage. Since amlodipine absorption is slow, gastric lavage may be worthwhile in some cases. Available data suggest that gross overdosage would result in excessive peripheral vasodilation with subsequent marked and probably prolonged systemic hypotension. Clinically significant hypotension due to amlodipine overdosage calls for active cardiovascular support including monitoring of cardiac and respiratory function, elevation of extremities and attention to circulating fluid volume and urine output. A vasoconstrictor agent may be helpful in restoring vascular tone and blood pressure, provided that there is no contradiction to its use. Since amlodipine is highly protein-bound, dialysis is unlikely to be of benefit.
Patients with known hypersensitivity to amlodipine.
Increased Angina and/or Myocardial Infarction: Rarely, patients, particularly those with severe obstructive coronary artery disease, have developed documented increased frequency, duration and/or severity of angina or acute myocardial infarction on starting calcium channel blocker therapy or at the time of dosage increase. The mechanism of this effect has not been elucidated.
Use in pregnancy & lactation: Safety of amlodipine in human pregnancy and lactation has not been established. Therefore, amlodipine should not be administered during pregnancy or lactation or to women of childbearing potential unless effective contraception is used.
Use in children: Since there is no clinical experience in patients <18 years, use in children is not currently recommended.
Safety of amlodipine in human pregnancy and lactation has not been established. Therefore, amlodipine should not be administered during pregnancy or lactation or to women of childbearing potential unless effective contraception is used.
The most commonly observed side effects were headache, oedema, fatigue, nausea, flushing and dizziness.
Amlodipine has been safely administered with thiazide diuretics, β-adrenoceptor blocking drugs, angiotensin-converting enzyme inhibitor, long-acting nitrates, sublingual glyceryl nitrate, nonsteroidal anti-inflammatory drugs, antibiotics and oral hypoglycaemic agents. Co-administration of cimetidine did not alter the pharmacokinetics of amlodipine. In vitro data from studies with human plasma indicate that amlodipine has no effect on protein-binding of digoxin, phenytoin, warfarin or indomethacin.
C08CA01 - amlodipine ; Belongs to the class of dihydropyridine derivative selective calcium-channel blockers with mainly vascular effects. Used in the treatment of cardiovascular diseases.
Tab 5 mg x 3 x 10's. 10 mg x 3 x 10's.
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