Alonet Tablets 50 mg: Each tablet contains: Atenolol 50 mg.
Alonet Tablets 100 mg: Each tablet contains: Atenolol 100 mg.
Excipients/Inactive Ingredients: Microcrystalline Cellulose, Carboxymethyl Cellulose Calcium, Talc, Magnesium Stearate, Colloidal Silicon Dioxide, Isopropyl Alcohol, Hydroxypropyl Methylcellulose, Dimethylpolysiloxane, Purified Water.
Pharmacology: Pharmacodynamics: Atenolol is a beta-blocker which is beta1-selective (i.e. acts preferentially on beta1-adrenergic receptors in the heart). Selectivity decreases with increasing dose.
Atenolol is without intrinsic sympathomimetic and membrane-stabilising activities and as with other beta-blockers, has negative inotropic effects.
As with other beta-blockers, the mode of action of atenolol in the treatment of hypertension is unclear.
It is probably the action of atenolol in reducing cardiac rate and contractility which makes it effective in eliminating or reducing the symptoms of patients with angina.
Pharmacokinetics: Absorption of atenolol following oral dosing is consistent but incomplete (approximately 40-50%) with peak plasma concentrations occurring 2-4 hours after dosing. The atenolol blood levels are consistent and subject to little variability. There is no significant hepatic metabolism of atenolol and more than 90% of that absorbed reaches the systemic circulation unaltered. Atenolol penetrates tissues poorly due to its low lipid solubility and its concentration in brain tissue is low. Plasma protein binding is low (approximately 3%). The plasma half-life is about 6 hours but this may rise in severe renal impairment since the kidney is the major route of elimination.
Hypertension, angina pectoris.
Adults: To be taken orally.
Hypertension: 50-100 mg tablet daily. Most patients respond to 100 mg daily given orally as a single dose. Some patients, however, will respond to 50 mg given as a single daily dose. The effect will be fully established after one to two weeks.
Angina pectoris: Most patients with angina pectoris will respond to 100 mg given orally once daily or 50 mg given twice daily. It is unlikely that additional benefit will be gained by increasing the dose.
Elderly: Dosage requirements may be reduced, especially in patients with impaired renal function.
Renal impairment: Since atenolol tablets are excreted via the kidneys, the dosage should be adjusted in cases of severe impairment of renal function.
No significant accumulation of atenolol occurs in patients who have a creatinine clearance greater than 35 ml/min/1.73 m2.
For patients with a creatinine clearance of 15-35 ml/min/1.73 m2, the oral dose should be 50 mg daily.
For patients with a creatinine clearance of less than 15 ml/min/1.73 m2 (equivalent to serum creatinine of greater than 600 micromol/litre), the oral dose should be 25 mg daily or 50 mg on alternate days.
Symptoms: The symptoms of overdosage may include bradycardia, hypotension, acute cardiac insufficiency and bronchospasm.
Treatment: General treatment should include: close supervision; treatment in an intensive care ward; the use of gastric lavage; activated charcoal and a laxative to prevent absorption of any drug still present in the gastrointestinal tract; the use of plasma or plasma substitutes to treat hypotension and shock. The possible uses of haemodialysis or haemoperfusion may be considered.
Contraindicated in patients with hypersensitivity to atenolol, cardiogenic shock, uncontrolled heart failure, sick sinus syndrome, second- or third-degree heart block, untreated phaeochromocytoma, metabolic acidosis, bradycardia (<45 bpm), hypotension and severe peripheral arterial circulatory disturbances.
Atenolol should not be withdrawn abruptly. The dosage should be withdrawn gradually over a period of 7-14 days, to facilitate a reduction in beta-blocker dosage. Patients should be followed during withdrawal, especially those with ischaemic heart disease.
Atenolol may be used in patients whose signs of heart failure have been controlled, although it is contraindicated in uncontrolled heart failure. Caution must be exercised in patients whose cardiac reserve is poor.
Atenolol may increase the number and duration of angina attacks in patients with Prinzmetal's angina due to unopposed alpha-receptor mediated coronary artery vasoconstriction.
Due to its negative effect on conduction time, caution must be exercised if it is given to patients with first-degree heart block.
Atenolol may mask the symptoms of hypoglycaemia, in particular, tachycardia.
Atenolol may mask the signs of thyrotoxicosis.
Atenolol may cause a more severe reaction to a variety of allergens when given to patients with a history of anaphylactic reaction to such allergens. Such patients may be unresponsive to the usual doses of adrenaline (epinephrine) used to treat the allergic reactions.
Atenolol may cause a hypersensitivity reaction including angioedema and urticaria.
Although cardioselective (beta1) beta-blockers may have less effect on lung function than non-selective beta-blockers, as with all beta-blockers, these should be avoided in patients with reversible obstructive airways disease, unless there are compelling clinical reasons for their use. Where such reasons exist, atenolol may be used with caution. Occasionally, some increase in airways resistance may occur in asthmatic patients however, and this may usually be reversed by commonly used dosage of bronchodilators such as salbutamol or isoprenaline.
Atenolol crosses the placental barrier and appears in the cord blood. No studies have been performed on the use of atenolol in the 1st trimester and the possibility of foetal injury cannot be excluded. Atenolol has been used under close supervision for the treatment of hypertension in the 3rd trimester. Administration of atenolol for longer period to pregnant women in the management of mild to moderate hypertension has been associated with intrauterine growth retardation. The use of atenolol in women who are, or may become pregnant, requires that the anticipated benefit be weighed against the possible risks, particularly in the 1st and 2nd trimester. There is significant accumulation of atenolol in breast milk. Caution should be exercised when atenolol is administered to a nursing mother.
Bradycardia, cold extremities, postural hypotension, dizziness, fatigue, skin rash, and dry eyes.
Combined use of beta-blockers and calcium channel blockers with negative inotropic effects, e.g. verapamil and diltiazem, can lead to an exaggeration of these effects particularly in patients with impaired ventricular function and/or sinoatrial or atrioventricular conduction abnormalities. This may result in severe hypotension, bradycardia and cardiac failure. Neither the beta-blocker nor the calcium channel blocker should be administered intravenously within 48 hours of discontinuing the other.
Concomitant therapy with dihydropyridines, e.g. nifedipine, may increase the risk of hypotension, and cardiac failure may occur in patients with latent cardiac insufficiency.
Digitalis glycosides, in association with beta-blockers, may increase atrioventricular conduction time.
Beta-blockers may exacerbate the rebound hypertension which can follow the withdrawal of clonidine. If the two drugs are co-administered, the beta-blocker should be withdrawn several days before discontinuing clonidine. If replacing clonidine by beta-blocker therapy, the introduction of beta-blockers should be delayed for several days after clonidine administration has stopped.
Class I anti-arrhythmic drugs (e.g., disopyramide) and amiodarone may have a potentiating effect on atrial-conduction time and induce negative inotropic effect.
Concomitant use of sympathomimetic agents, e.g. adrenaline (epinephrine), may counteract the effect of beta-blockers.
Concomitant use with insulin and oral antidiabetic drugs may lead to the intensification of the blood sugar lowering effects of these drugs. Symptoms of hypoglycaemia, particularly tachycardia, may be masked.
Concomitant use of prostaglandin synthetase-inhibiting drugs, e.g. ibuprofen and indomethacin, may decrease the hypotensive effects of beta-blockers.
Store below 30°C. Protect from light and moisture.
Shelf-Life: 3 years from the date of manufacture.
C07AB03 - atenolol ; Belongs to the class of selective beta-blocking agents. Used in the treatment of cardiovascular diseases.
Alonet tab 100 mg
10 × 10's
Alonet tab 50 mg
10 × 10's
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