Atenolol

BOXED WARNING Cessation of Therapy with Atenolol Patients with coronary artery disease, who are being treated with atenolol, should be advised against abrupt discontinuation of therapy. Severe exacerbation of angina and the occurrence of myocardial infarction and ventricular arrhythmias have been reported in angina patients following the abrupt discontinuation of therapy with beta blockers. The last two complications may occur with or without preceding exacerbation of the angina pectoris. As with other beta blockers, when discontinuation of atenolol is planned, the patients should be carefully observed and advised to limit physical activity to a minimum. If the angina worsens or acute coronary insufficiency develops, it is recommended that atenolol be promptly reinstituted, at least temporarily. Because coronary artery disease is common and may be unrecognized, it may be prudent not to discontinue atenolol therapy abruptly even in patients treated only for hypertension. (See DOSAGE AND ADMINISTRATION).

Cardiac Failure Sympathetic stimulation is necessary in supporting circulatory function in congestive heart failure, and beta-blockade carries the potential hazard of further depressing myocardial contractility and precipitating more severe failure. In patients with acute myocardial infarction, cardiac failure which is not promptly and effectively controlled by 80 mg of intravenous furosemide or equivalent therapy is a contraindication to beta-blocker treatment. In Patients Without a History of Cardiac Failure Continued depression of the myocardium with beta-blocking agents over a period of time can, in some cases, lead to cardiac failure. At the first sign or symptom of impending cardiac failure, patients should be treated appropriately according to currently recommended guidelines, and the response observed closely. If cardiac failure continues despite adequate treatment, atenolol should be withdrawn (see DOSAGE AND ADMNISTRATION).

Most adverse effects have been mild and transient. The frequency estimates in the following table were derived from controlled studies in hypertensive patients in which adverse reactions were either volunteered by the patient (U.S. studies) or elicited, e.g., by checklist (foreign studies). The reported frequency of elicited adverse effects was higher for both atenolol and placebo-treated patients than when these reactions were volunteered. Where frequency of adverse effects of atenolol and placebo is similar, causal relationship to atenolol is uncertain. Volunteered (US Studies) Total-Volunteered and Elicited (Foreign + U.S. Studies) Atenolol (n = 164) % Placebo (n = 206) % Atenolol (n = 339) % Placebo (n = 407) % CARDIOVASCULAR Bradycardia 3 0 3 0 Cold Extremities 0 0.5 12 5 Postural Hypotension 2 1 4 5 Leg Pain 0 0.5 3 1 CENTRAL NERVOUS SYSTEM/ NEUROMUSCULAR Dizziness 4 1 13 6 Vertigo 2 0.5 2 0.2 Lightheadedness 1 0 3 0.7 Tiredness 0.6 0.5 26 13 Fatigue 3 1 6 5 Lethargy 1 0 3 0.7 Drowsiness 0.6 0 2 0.5 Depression 0.6 0.5 12 9 Dreaming 0 0 3 1 GASTROINTESTINAL Diarrhea 2 0 3 2 Nausea 4 1 3 1 RESPIRATORY (see WARNINGS) Wheeziness 0 0 3 3 Dyspnea 0.6 1 6 4 Acute Myocardial Infarction In a series of investigations in the treatment of acute myocardial infarction, bradycardia and hypotension occurred more commonly, as expected for any beta-blocker, in atenolol-treated patients than in control patients. However, these usually responded to atropine and/or to withholding further dosage of atenolol. The incidence of heart failure was not increased by atenolol. Inotropic agents were infrequently used. The reported frequency of these and other events occurring during these investigations is given in the following table. In a study of 477 patients, the following adverse events were reported during either intravenous and/or oral atenolol administration: Conventional Therapy Plus Atenolol (n = 244) Conventional Therapy Alone (n = 233) Bradycardia 43 (18%) 24 (10%) Hypotension 60 (25%) 34 (15%) Bronchospasm 3 (1.2%) 2 (0.9%) Heart Failure 46 (19%) 56 (24%) Heart Block 11 (4.5%) 10 (4.3%) BBB + Major Axis Deviation 16 (6.6%) 28 (12%) Supraventricular Tachycardia 28 (11.5%) 45 (19%) Atrial Fibrillation 12 (5%) 29 (11%) Atrial Flutter 4 (1.6%) 7 (3%) Ventricular Tachycardia 39 (16%) 52 (22%) Cardiac Reinfarction 0 (0%) 6 (2.6%) Total Cardiac Arrests 4 (1.6%) 16 (6.9%) Nonfatal Cardiac Arrests 4 (1.6%) 12 (5.1%) Deaths 7 (2.9%) 16 (6.9%) Cardiogenic Shock 1 (0.4%) 4 (1.7%) Development of Ventricular Septal Defect 0 (0%) 2 (0.9%) Development of MitralRegurgitation 0 (0%) 2 (0.9%) Renal Failure 1 (0.4%) 0 (0%) Pulmonary Emboli 3 (1.2%) 0 (0%) In the subsequent International Study of Infarct Survival (ISIS-1) including over 16,000 patients of whom 8,037 were randomized to receive atenolol treatment, the dosage of intravenous and subsequent oral atenolol was either discontinued or reduced for the following reasons: Reasons for Reduced Dosage IV Atenolol Reduced Dose (< 5 mg)* Oral Partial Dose Hypotension/Bradycardia 105 (1.3%) 1168 (14.5%) Cardiogenic Shock 4 (0.04%) 35 (0.44%) Reinfarction 0 (0%) 5 (0.06%) Cardiac Arrest 5 (0.06%) 28 (0.34%) Heart Block (> first degree) 5 (0.06%) 143 (1.7%) Cardiac Failure 1 (0.01%) 233 (2.9%) Arrhythmias 3 (0.04%) 22 (0.27%) Bronchospasm 1 (0.01%) 50 (0.62%) *Full dosage was 10 mg and some patients received less than 10 mg but more than 5 mg. During postmarketing experience with atenolol, the following have been reported in temporal relationship to the use of the drug: elevated liver enzymes and/or bilirubin, hallucinations, headache, impotence, Peyronie’s disease, postural hypotension which may be associated with syncope, psoriasiform rash or exacerbation of psoriasis, psychoses, purpura, reversible alopecia, thrombocytopenia, visual disturbance, sick sinus syndrome, and dry mouth. Atenolol, like other beta-blockers, has been associated with the development of antinuclear antibodies (ANA), lupus syndrome, and Raynaud’s phenomenon. POTENTIAL ADVERSE EFFECTS In addition, a variety of adverse effects have been reported with other beta-adrenergic blocking agents, and may be considered potential adverse effects of atenolol. Hematologic: Agranulocytosis. Allergic: Fever, combined with aching and sore throat, laryngospasm, and respiratory distress. Central Nervous System: Reversible mental depression progressing to catatonia; an acute reversible syndrome characterized by disorientation of time and place; short-term memory loss; emotional lability with slightly clouded sensorium; and, decreased performance on neuropsychometrics. Gastrointestinal: Mesenteric arterial thrombosis, ischemic colitis. Other: Erythematous rash. Miscellaneous: There have been reports of skin rashes and/or dry eyes associated with the use of beta-adrenergic blocking drugs. The reported incidence is small, and in most cases, the symptoms have cleared when treatment was withdrawn. Discontinuance of the drug should be considered if any such reaction is not otherwise explicable. Patients should be closely monitored following cessation of therapy (see INDICATIONS AND USAGE). The oculomucocutaneous syndrome associated with the beta-blocker practolol has not been reported with atenolol. Furthermore, a number of patients who had previously demonstrated established practolol reactions were transferred to atenolol therapy with subsequent resolution or quiescence of the reaction. To report side effects, you can call (866) 562-4597 or (800) FDA-1088.