Atenolol

31/03/2009 12:45

Atenolol

Brand Name: Apo-Atenolol (CAN), Gen-Atenolol (CAN), Novo-Atenol (CAN), Tenolin (CAN), Tenormin

Pregnancy Category D

Drug classes: Beta1-selective adrenergic blocking agent, Antianginal drug, antihypertensive drug

 

Therapeutic actions

Blocks beta-adrenergic receptors of the sympathetic nervous system in the heart and juxtaglomerular apparatus (kidney), thus decreasing the excitability of the heart, decreasing cardiac output and oxygen consumption, decreasing the release of renin from the kidney, and lowering blood pressure.

 

Indications

· Treatment of angina pectoris due to coronary atherosclerosis

· Hypertension, as a step 1 agent, alone or with other drugs, especially diuretics

· Treatment of myocardial infarction

· Unlabeled uses: prevention of migraine headaches; alcohol withdrawal syndrome, treatment of ventricular and supraventricular arrhythmias

 

Contraindications

· Contraindicated with sinus bradycardia, second- or third-degree heart block, cardiogenic shock, CHF.

· Use cautiously with renal failure, diabetes or thyrotoxicosis (atenolol can mask the usual cardiac signs of hypoglycemia and thyrotoxicosis), lactation.

 

Adverse effects

Pharyngitis, erythematous rash, fever, sore throat, laryngospasm, respiratory distress, Dizziness, vertigo, tinnitus, fatigue, emotional depression, paresthesias, sleep disturbances, hallucinations, disorientation, memory loss, slurred speech, Bradycardia, CHF, cardiac arrhythmias, sinoatrial or AV nodal block, tachycardia, peripheral vascular insufficiency, claudication, CVA, pulmonary edema, hypotension, Eye irritation, dry eyes, conjunctivitis, blurred vision, Gastric pain, flatulence, constipation, diarrhea, nausea, vomiting, anorexia, ischemic colitis, renal and mesenteric arterial thrombosis, retroperitoneal fibrosis, hepatomegaly, acute pancreatitis, Impotence, decreased libido, Peyronie's disease, dysuria, nocturia, frequent urination, Joint pain, arthralgia, muscle cramp, Bronchospasm, dyspnea, cough, bronchial obstruction, nasal stuffiness, rhinitis, pharyngitis (less likely than with propranolol), Decreased exercise tolerance, development of antinuclear antibodies, hyperglycemia or hypoglycemia, elevated serum transaminase, alkaline phosphatase, and LDH

 

Drug Interactions

· Increased effects with verapamil, anticholinergics, quinidine

· Increased risk of orthostatic hypotension with prazosin

· Increased risk of lidocaine toxicity with atenolol

· Possible increased blood pressure-lowering effects with aspirin, bismuth subsalicylate, magnesium salicylate, sulfinpyrazone, oral contraceptives

· Decreased antihypertensive effects with NSAIDs, clonidine

· Decreased antihypertensive and antianginal effects of atenolol with ampicillin, calcium salts

· Possible increased hypoglycemic effect of insulin

 

· Possible false results with glucose or insulin tolerance tests

 

Nursing considerations

· Do not discontinue drug abruptly after long-term therapy (hypersensitivity to catecholamines may have developed, causing exacerbation of angina, MI, and ventricular arrhythmias). Taper drug gradually over 2 wk with monitoring.

· Consult physician about withdrawing drug if patient is to undergo surgery (withdrawal is controversial).