Overview
DESCRIPTION Atenolol, a synthetic, beta 1 -selective (cardioselective) adrenoreceptor blocking agent, may be chemically described as benzeneacetamide, 4 -[2'-hydroxy-3'-[(1- methylethyl) amino] propoxy]-. The structural and molecular formulas are: Atenolol (free base) has a molecular weight of 266.34. It is a relatively polar hydrophilic compound with a water solubility of 26.
Mechanism of Action
CLINICAL PHARMACOLOGY Atenolol is a beta 1 -selective (cardioselective) beta-adrenergic receptor blocking agent without membrane stabilizing or intrinsic sympathomimetic (partial agonist) activities. This preferential effect is not absolute, however, and at higher doses, atenolol inhibits beta 2 -adrenoreceptors, chiefly located in the bronchial and vascular musculature. Pharmacokinetics and Metabolism In man, absorption of an oral dose is rapid and consistent but incomplete. Approximately 50% of an oral dose is absorbed from the gastrointestinal tract, the remainder being excreted unchanged in the feces. Peak blood levels are reached between two (2) and four (4) hours after ingestion.
Indications
- INDICATIONS AND USAGE Hypertension Atenolol tablets are indicated for the treatment of hypertension, to lower blood pressure. Lowering blood pressure lowers the risk of fatal and non-fatal cardiovascular events, primarily strokes and myocardial infarctions. These benefits have been seen in controlled trials of antihypertensive drugs from a wide variety of pharmacologic classes including atenolol. Control of high blood pressure should be part of comprehensive cardiovascular risk management, including, as appropriate, lipid control, diabetes management, antithrombotic therapy, smoking...
Common Doses
- 50 mg
- 100 mg
- 200 mg
- 5 mg
Dosage
DOSAGE AND ADMINISTRATION Hypertension The initial dose of atenolol is 50 mg given as one tablet a day either alone or added to diuretic therapy. The full effect of this dose will usually be seen within one to two weeks. If an optimal response is not achieved, the dosage should be increased to atenolol 100 mg given as one tablet a day. Increasing the dosage beyond 100 mg a day is unlikely to produce any further benefit. Atenolol may be used alone or concomitantly with other antihypertensive agents including thiazide-type diuretics, hydralazine, prazosin, and alpha-methyldopa.
Contraindications
- CONTRAINDICATIONS Atenolol tablets are contraindicated in sinus bradycardia, heart block greater than first degree, cardiogenic shock, and overt cardiac failure. (See WARNINGS .) Atenolol tablets are contraindicated in those patients with a history of hypersensitivity to the atenolol or any of the drug product’s components.
Side Effects
- ADVERSE REACTIONS Most adverse effects have been mild and transient. The frequency estimates in the following table were derived from controlled studies in hypertensive patients in which adverse reactions were either volunteered by the patient (U.S. studies) or elicited, e.g., by checklist (foreign studies). The reported frequency of elicited adverse effects was higher for both atenolol and placebo-treated patients than when these reactions were volunteered. Where frequency of adverse effects of atenolol and placebo is similar, causal relationship to atenolol is uncertain. Volunteered (U.S.
Interactions
- Drug Interactions Catecholamine-depleting drugs (e.g., reserpine) may have an additive effect when given with beta-blocking agents. Patients treated with atenolol plus a catecholamine depletor should therefore be closely observed for evidence of hypotension and/or marked bradycardia which may produce vertigo, syncope, or postural hypotension. Calcium channel blockers may also have an additive effect when given with atenolol (see WARNINGS ). Disopyramide is a Type I antiarrhythmic drug with potent negative inotropic and chronotropic effects.