Dosage/Direction for Use
Oral Chronic stable angina, Hypertension Adult: Per tablet contains atenolol 25 or 50 mg and amlodipine (as besylate) 5 mg: 1 tab once daily, may increase to 2 tablets daily if needed. Elderly: Per tablet contains atenolol 25 mg and amlodipine (besylate) 5 mg: Initiate with 1 tablet daily. Renal impairment: Per tablet contains atenolol 25 mg and amlodipine (besylate) 5 mg: Initiate with 1 tablet daily. |
Contraindications
Hypotension, sinus bradycardia, 2nd & 3rd degrees of heart block, cardiogenic shock, overt congestive failure, poor LV function, hypersensitivity to either component, pregnancy.
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Special Precautions
Excessive fall of BP may occur in elderly patients. Caution in patients with COPD, thyrotoxicosis, congestive failure, vasospastic angina, hepatic & renal impairment. Caution in diabetic patients as beta-blockers may mask tachycardia occurring with hypoglycaemia. Withdrawal should be gradual. Lactation. Safety and efficacy have not been established in children. Not to be used in untreated phaeochromocytoma.
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Adverse Reactions
Headache, hypotension, dizziness, breathlessness, fatigue, muscle cramps, bradycardia, palpitations, flushing, oedema, dyspnoea, dyspepsia, cold extremities. Drowsiness, chestpain & impotence rarely. Hypersensitivity reactions.
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Overdosage
Overdosage may cause hypotension and less commonly, congestive cardiac failure. Unabsorbed drug may be removed by gastric lavage or use of activated charcoal. Symptomatic treatment may be administered.
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Drug Interactions
Additive effect when used with catecholamine depleting drugs; monitor for hypotension and/or marked bradycardia. If used with clonidine, clonidine withdrawal should occur a few days after withdrawal of the beta-blocker to prevent rebound hypertension; if replacing clonidine by beta-blocker, beta-blocker should be introduced only after clonidine administration has stopped for several days. Concurrent use with prostaglandin synthase inhibiting drugs (e.g. indomethacin) may reduce the hypotensive effects of beta-blockers.
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Action
Atenolol is a cardioselective beta blocker. Amlodipine is a dihydropyridine calcium-channel blocker that blocks the transmembrane influx of calcium ions into vascular smooth muscle and cardiac muscle.
Combination of the two drugs results in additive antihypertensive action.
Absorption: Amlodipine: Plasma levels peak 6-12 hr after oral admin; absolute bioavailability is estimated to be 64-90%. Atenolol: Absorption is rapid and consistent but incomplete; about 50% of an oral dose is absorbed in the GI tract; plasma levels peak 2-4 hr after oral admin. Distribution: Amlodipine: 93% bound to plasma proteins. Atenolol: 6-16% bound to plasma proteins. Metabolism: Amlodipine: About 90% converted to inactive metabolites hepatically. Atenolol: Little or no hepatic metabolism. Excretion: Amlodipine: 10% of parent compound and 60% of the metabolites are removed in the urine; elimination from the plasma is biphasic with terminal half-life of about 30-50 hr. Atenolol: 50% of the oral dose is removed unchanged in the faeces; absorbed drug is removed mainly via renal elimination; half-life is about 6-7 hr. |
CIMS Class
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ATC Classification
C08CA01 - amlodipine ; Belongs to the class of dihydropyridine derivative selective calcium-channel blockers with mainly vascular effects. Used in the treatment of cardiovascular diseases.
C07AB03 - atenolol ; Belongs to the class of selective beta-blocking agents. Used in the treatment of cardiovascular diseases. |