International generic name Atenolol
Drug form and composition Film-coated tablets. One tablet contains 50 mg Atenolol.
Indications Stable and non-stable angina pectoris, which are due to coronary artery sclerosis; arterial hypertension of different genesis (including renal hypertension).
Dosage and administration Usual dosage in patients with angina pectoris and hypertension is 50-100 mg ones daily, as the effect becomes evident 1-2 weeks after initial dose. In patients with renal failure the dose should be corrected depending on the creatine clearance. If the clearance of creatine is 15-35 ml per minute, the dosage of Atenolol should be 50 mg ones daily; if the clearance is lower than 15 ml per minute, the same dose should be given each second day.
Contraindications Second or third degree heart block; heart failure with decompensated hemodynamics; hypotension in myocardial infarction; cardiogenic shock; sinus node bradicardia (below 45 beats per minute); hypersensitivity to the preparation. Atenolol mustn’t be given to children.
Special warnings and precautions In case of abrupt interruption of medication with Atenolol is possible to appear “withdrawal syndrome”, manifesting with severely heart disorders. This phenomenon is explained with a sensibilization of the beta-adrenergic receptors and increased norepinephrine releasing. For this reason the treatment with the preparation should be reduced gradually. In patients with bronchial asthma and COPD Atenolol may cause a bronchial obstruction and provoke an asthmatic attack, which due to blocking of the beta-adrenergic bronchial dilation. Atenolol should be administered with caution in patient with diabetes mellitus, as it may mask the tachycardia in case of hypoglycemia. In impending surgery under general anesthesia the treatment should be stopped 48 hours before operation. In pregnancy and lactation Atenolol is used only in cases with favourable risk/benefit ratio.
Drug interactions In concomitant treatment with clonidin, Atenolol is withdrawn several days prior to clonidin interruption, in order to avoid the clonidin “steal” syndrome. Atenolol intensifies the hypoglycemia, caused by sulphonylurea preparations, depressing the contraregulatory mechanisms; enhances the negative chronotropic and dromotropic effects of the centrally acting antihyprtensive drugs, as reserpin and methyldopa; accentuates antiarrhythmic capabilities of the calcium channel blocking agents (verapamil, diltiazem); potentiates action of the nondepolarizing neuromuscular blocking agents. Concomitant treatment with Atenolol and digitalis glycosides may lead to bradicardia and heart block, which requires an ECG-monitoring. Cimmetidin elevates the plasma level of the Atenolol and increases its effects. Concomitant application of NSAID may reduce the antihypertensive effect of Atenolol, due to suppression of the renal synthesis of prostaglandines as well as fluid and sodium ions retention.
Adverse reactions Following adverse reactions may be seen: hypotonia; bradicardia; paresthesies; cold limbs; exacerbation of the peripheral circulation disturbances; fatigue; dizziness; headache; nausea and gastrointestinal symptoms; hypersensitivity reactions, particularly skin manifestations. Rarely may appear heart failure aggravation; AV - block; bronchial obstruction; depression; hypoglycemia; thrombocytopenia; hyperlipemia.
Pharmacological mechanisms Atenolol is a selective antagonist of the β1 - receptors, and has no membrane stabilizing and internal sympathicomimetic action. The basis of its antihypertensive action is depression of the renal renine secretion. Relive of the angina pectoris symptoms is due to reduction of the oxygen requirements of the myocardium. Atenolol reduces the cardiac output and contractility. In therapeutic dose it influences chronotrope, inotrope and dromotrope effects of the cardiac sympathetic stimulation. Its effects are better manifested during exercise and elevated sympathetic tone.
Supplied 30 film-coated tablets Atenolol of 50 mg.
Expiry 2 years. |