Atenolol
Atenolol-Tedapharm
Beta blocker (cardioselective) (beta1- selective)
Hypertension / Angina pectoris (Martindale,PDR)
Mechanism of action / Pharmacokinetics
Atenolol is a beta1-selective (cardioselective) beta-adrenergic receptor blocking agent without membrane stabilizing or intrinsic sympathomimetic (partial agonist) activities, however , at higher doses, atenolol inhibits beta2-adrenoreceptors, chiefly located in
the bronchial and vascular musculature. (PDR)
Pharmacokinetic properties
Hypertension , Chronic angina pectoris, Cardiac arrhythmias, hemodynamically stable patients with definite or suspected acute myocardial infarction, mitral valve prolapse syndrome. prophylaxis of migraine, tremor. (USPDI,Facts,Martindale)
Contraindications
Anenolol is contraindicated in sinus bradycardia, heart block greater than first degree, cardiogenic shock, CHF unless secondary to a tachyarrhythmia treatable with B-blockers, overt cardiac failure and in those patients with a history of hypersensivity to the B-blockers or any of the drug product’s components. (Facts,PDR)
Warnings and precautions
- Patient with bronchospastic disease should, in general, not receive beta blockers.
- Patients with coronary artery disease, who are being treated with atenolol should be advised against abrupt discontinuation of therapy.
- Atenolol should not given to patient with untreated pheochro- mocytoma.
- Initial and subsequent atenolol dosages can be adjusted downward depending on clinical observation including pulse and blood pressure. atenolol may be aggravate peripheral arterial circulatory disorders.
- Atenolol should be used with coution in diabetic patients and in patient with impaired renal function.
- Care should be taken when using anesthetic agent. (PDR,Martindale)
pregnancy
Category D
Atenolol can cause fetal harm when administered to a pregnant woman (PDR)
Breast - Feeding
Atenolol is excreted in human breast milk.Caution should be exercised when atenolol is administered to a nursing woman. breast-fed infants should be monitored for signs of beta-adrenergic blockade, especially bradycardia, hypotension, respiratory distress and hypoglycemia. (PDR,USPDI)
Drug Interactions
1- CCBs, cimetidine, oral contraceptive, flecainide, haloperidol, hydralazine, hydroxychloroquine, quinidine, quinolones, SSRIs, epinephrine, ergot alkaloids and prazosin may also have an additive effect when given with atenolol.
2- NSAIDs, aluminum and calcium salts,barbiturates,cholestyramine, colestipol, ampicillin, rifampin may decrease the hypotensive effects of atenolol.
3- Digital with atenolol slows AV conduction in CHF patients.
4- Life threatening and fatal increase in blood pressure have occured after discontinuation of clonidine in patients reciving atenolol or after simultaneous withdrawal. (Facts)
Adverse reactions
Bradycardia; coldness of extremities; heart failure; heart block; bronchospasm; fatigue; hypotension; mental depression; headache; dizziness; hallucination; nausea; vomiting; diarrhoea; constipation; abdominal cramping; confusion; sleep disturbances including nightmares; hypoglycaemia, hyperglycaemia; changes in blood concentrations of TG and cholesterol; skin rash; exacerbation psoriasis; blurred vision. (Martindale)
Overdosage
Bradycardia; dizziness; severe,or fainting, hypotension; irregular heart beat, difficulty breathing; bluish-colored fingernails or polms of hands; or seizures. (USPDI)
Dosage and Administration
Usual adult dose
- Antihypertensive
Oral, initially 25 to 50 mg once a day, the dosage being increased
to 50 to 100 mg a day after two weeks if necessary.
- Antianginal
Oral, initially 50 mg once a day, the dosage being increased gradually to 100 mg a day after one week if necessary. Some patients may require up to 200 mg a day.
- Myocardial infarction
In patients who tolerate the full intravenous dose:
oral, initially 50 mg ten minuts after the last intravenous dose, followed by another 50 mg twelve hours later. A dose of 100 mg once a day or 50 mg two times a day may then be given for six to nine days or until discharge from the hospital.
Geriatric patients may have increased or decreased sensitivity to the effects of unusual dose.
For patient with sever renal function impairment the following monitoring doses are recommended. (USPDI)
Atenolol
Creatinine Clearance Elimination maximum
(ml/min /1.73 m ) Half-Life (h) Dosage
15-35 16-27 50 mg daily
<15 >27 25 mg daily
Storage
Store below 30 and away from moisture and direct light.(USPDI)
How Supplied
Atenolol is available as 50 and 100 mg , biconvex , scored , orange and film - coated tablets. There are blisters of 10 10 in a box of 100’s.
Reference
1- PDR 2006 2-USPDI 2006 3-USPDI 2004
4- Martindale 2007 5- Drug Facts 2004M company