ATENOLOL (TENORMIN)

Atenolol (Tenormin) is an antianginal and antihypertensive drug used to treat angina pectoris and during the medical therapy of MI.

Generic & Brand Names
Apo-Atenolol (CAN), Gen-Atenolol (CAN), Novo-Atenol (CAN), Tenormin

Pregnancy Category D

Drug classes

• Beta1-selective adrenergic blocker
• Antianginal
• Antihypertensive

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 BP.

Indications

• Treatment of angina pectoris due to coronary atherosclerosis
• Hypertension, as a step 1 agent, alone or with other drugs, especially diuretics
• Treatment of MI
• Unlabeled uses: Prevention of migraine headaches; alcohol withdrawal syndrome, treatment of ventricular and supraventricular arrhythmias

Dosage & Route

• Available forms: Tablets—25, 50, 100 mg; injection—5 mg/10 mL

ADULTS

• Hypertension: Initially, 50 mg PO once a day; after 1–2 wk, dose may be increased to 100 mg/day.
• Angina pectoris: Initially, 50 mg PO daily. If optimal response is not achieved in 1 wk, increase to 100 mg daily; up to 200 mg/day may be needed.
• Acute MI: Initially, 5 mg IV given over 5 min as soon as possible after diagnosis; follow with IV injection of 5 mg 10 min later. Switch to 50 mg PO 10 min after the last IV dose; follow with 50 mg PO 12 hr later. Thereafter, administer 100 mg PO daily or 50 mg PO bid for 6–9 days or until discharge from the hospital.

PEDIATRIC PATIENTS

Safety and efficacy not established.

Adverse effects

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

Contraindications

• Contraindicated with sinus bradycardia, second- or third-degree heart block, cardiogenic shock, CHF, pregnancy.
• Use cautiously with renal failure, diabetes or thyrotoxicosis (atenolol can mask the usual cardiac signs of hypoglycemia and thyrotoxicosis), lactation, respiratory disease.

Patient Education

• Take drug with meals if GI upset occurs.
• Do not stop taking this drug unless told to do so by a health care provider.
• Avoid driving or dangerous activities if dizziness or weakness occurs.
• You may experience these side effects: Dizziness, light-headedness, loss of appetite, nightmares, depression, sexual impotence.
• Report difficulty breathing, night cough, swelling of extremities, slow pulse, confusion, depression, rash, fever, sore throat.