Atenolol (Atenolol)
Overview of Atenolol
Atenolol is a competitive,ß-1 selective adrenergic antagonist, similar to metoprolol. ß-adrenergic antagonists counter the effect of sympathomimetic neurotransmitters (i.e., catecholamines) by competing for receptor sites. Similar to metoprolol, it, in low doses, selectively blocks sympathetic stimulation mediated by ß-adrenergic receptors in the heart and vascular smooth muscle. It antagonizes ß1 receptors at doses 50 to 100 times less than those required to block ß2 receptors. This cardioselectivty is more pronounced at low doses and is lost at high doses. It lowers the blood pressure in hypertension and slows the heart rate.
Indication of Atenolol
Atenolol is primarily indicated in conditions like Angina, Angina pectoris, Cardiac arrhythmia, Early intervention within 12 hrs of myocardial infarction, Hypertension, Myocardial infarction, To prevent recurrence of neural tube defect, and can also be given in adjunctive therapy as an alternative drug of choice in Alcohol withdrawal, Migraine prophylaxis.
Contraindication of Atenolol
Atenolol is contraindicated in conditions like Asthma,Depression,Heart failure,Cardiogenic shock,Bronchitis,Second or third degree A-V block.
Side Effects of Atenolol
The severe or irreversible adverse effects of Atenolol, which give rise to further complications include Hypotension, Bronchospasm, Impotence, AV-block, Agranulocytosis, Hyperglycemia, Sinus bradycardia, Oculomucocutaneous syndrome.,Atenolol produces potentially life-threatening effects which include Heart failure. which are responsible for the discontinuation of Atenolol therapy.,The signs and symptoms that are produced after the acute overdosage of Atenolol include Bradycardia, Convulsions, Coma, Ventricular asystole.,The symptomatic adverse reactions produced by Atenolol are more or less tolerable and if they become severe, they can be treated symptomatically, these include Dizziness, Fatigue, Alopecia, Diarrhea, Dyspnea, Cold extremities, Constipation, Insomnia, Pruritus, Impotence, Depression, Blood dyscrasias, Exfoliative dermatitis, Paresthesias, Hyperpigmentation, Wheezing, Vivid dreams, Xerosis.
Precautions of Atenolol
Atenolol should be used with caution in patients with poorly controlled diabetes mellitus particularly brittle diabetes, in patients with liver or kidney impairments, in hyperthyroidism or thyrotoxicosis because the drug can mask the tachycardia that occur in this condition. Abrupt withdrawal of atenolol in hyperthyroidism patient can precipitate a thyroid storm. Avoid abrupt withdrawal in angina patients. Use with caution during pregnancy.