Atenolol: uses, appearance and warnings

Hypertension Atenolol tablets are indicated for the treatment of hypertension, to lower blood pressure. Lowering blood pressure lowers the risk of fatal and non-fatal cardiovascular events, primarily strokes and myocardial infarctions. These benefits have been seen in controlled trials of antihypertensive drugs from a wide variety of pharmacologic classes including atenolol. Control of high blood pressure should be part of comprehensive cardiovascular risk management, including, as appropriate, lipid control, diabetes management, antithrombotic therapy, smoking cessation, exercise, and limited sodium intake. Many patients will require more than 1 drug to achieve blood pressure goals. For specific advice on goals and management, see published guidelines, such as those of the National High Blood Pressure Education Program’s Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure (JNC). Numerous antihypertensive drugs, from a variety of pharmacologic classes and with different mechanisms of action, have been shown in randomized controlled trials to reduce cardiovascular morbidity and mortality, and it can be concluded that it is blood pressure reduction, and not some other pharmacologic property of the drugs, that is largely responsible for those benefits. The largest and most consistent cardiovascular outcome benefit has been a reduction in the risk of stroke, but reductions in myocardial infarction and cardiovascular mortality also have been seen regularly. Elevated systolic or diastolic pressure causes increased cardiovascular risk, and the absolute risk increase per mmHg is greater at higher blood pressures, so that even modest reductions of severe hypertension can provide substantial benefit. Relative risk reduction from blood pressure reduction is similar across populations with varying absolute risk, so the absolute benefit is greater in patients who are at higher risk independent of their hypertension (for example, patients with diabetes or hyperlipidemia), and such patients would be expected to benefit from more aggressive treatment to a lower blood pressure goal. Some antihypertensive drugs have smaller blood pressure effects (as monotherapy) in black patients, and many antihypertensive drugs have additional approved indications and effects (e.g., on angina, heart failure, or diabetic kidney disease). These considerations may guide selection of therapy. Atenolol tablets may be administered with other antihypertensive agents. Angina Pectoris Due to Coronary Atherosclerosis Atenolol tablets are indicated for the long-term management of patients with angina pectoris. Acute Myocardial Infarction Atenolol tablets are indicated in the management of hemodynamically stable patients with definite or suspected acute myocardial infarction to reduce cardiovascular mortality. Treatment can be initiated as soon as the patient’s clinical condition allows. (See DOSAGE AND ADMINISTRATION , CONTRAINDICATIONS , and WARNINGS .) In general, there is no basis for treating patients like those who were excluded from the ISIS-1 trial (blood pressure less than 100 mmHg systolic, heart rate less than 50 bpm) or have other reasons to avoid beta blockade. As noted above, some subgroups (e.g., elderly patients with systolic blood pressure below 120 mmHg) seemed less likely to benefit.

Atenolol Tablets, USP are available containing 25 mg, 50 mg or 100 mg of atenolol, USP. The 25 mg tablets are white to off-white, round, unscored tablets debossed with A2 on one side of the tablet and M on the other side. They are available as follows: NDC 0378-0218-01 bottles of 100 tablets NDC 0378-0218-10 bottles of 1000 tablets The 50 mg tablets are white, round, scored tablets debossed with 231 above the score on one side of the tablet and M on the other side. They are available as follows: NDC 0378-0231-01 bottles of 100 tablets NDC 0378-0231-10 bottles of 1000 tablets The 100 mg tablets are white, round, unscored tablets debossed with M on one side of the tablet and 757 on the other side. They are available as follows: NDC 0378-0757-01 bottles of 100 tablets NDC 0378-0757-10 bottles of 1000 tablets Store at 20° to 25°C (68° to 77°F). [See USP Controlled Room Temperature.] Dispense in a tight, light-resistant container as defined in the USP using a child-resistant closure. Distributed by: Mylan Pharmaceuticals Inc., a Viatris Company Morgantown, WV 26505 U.S.A. Revised: 2/2026 ALP:ATEN:R4

Atenolol tablets are contraindicated in sinus bradycardia, heart block greater than first degree, cardiogenic shock, and overt cardiac failure. (See WARNINGS .) Atenolol tablets are contraindicated in those patients with a history of hypersensitivity to the atenolol or any of the drug product’s components.

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 tablets should be withdrawn. (See DOSAGE AND ADMINISTRATION .) Cessation of Therapy with Atenolol Tablets Patients with coronary artery disease, who are being treated with atenolol tablets, 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 tablets 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 tablets be promptly reinstituted, at least temporarily. Because coronary artery disease is common and may be unrecognized, it may be prudent not to discontinue atenolol tablets therapy abruptly even in patients treated only for hypertension. (See DOSAGE AND ADMINISTRATION .) Concomitant Use of Calcium Channel Blockers Bradycardia and heart block can occur and the left ventricular end diastolic pressure can rise when beta-blockers are administered with verapamil or diltiazem. Patients with pre-existing conduction abnormalities or left ventricular dysfunction are particularly susceptible. (See PRECAUTIONS .) Bronchospastic Diseases PATIENTS WITH BRONCHOSPASTIC DISEASE SHOULD, IN GENERAL, NOT RECEIVE BETA-BLOCKERS. Because of its relative beta 1 selectivity, however, atenolol tablets may be used with caution in patients with bronchospastic disease who do not respond to, or cannot tolerate, other antihypertensive treatment. Since beta 1 selectivity is not absolute, the lowest possible dose of atenolol tablets should be used with therapy initiated at 50 mg and a beta 2 -stimulating agent (bronchodilator) should be made available. If dosage must be increased, dividing the dose should be considered in order to achieve lower peak blood levels. Major Surgery Chronically administered beta-blocking therapy should not be routinely withdrawn prior to major surgery, however the impaired ability of the heart to respond to reflex adrenergic stimuli may augment the risks of general anesthesia and surgical procedures. Hypoglycemia Beta-blockers may prevent early warning signs of hypoglycemia, such as tachycardia, and increase the risk for severe or prolonged hypoglycemia at any time during treatment, especially in patients with diabetes mellitus or children and patients who are fasting (i.e., surgery, not eating regularly, or are vomiting). If severe hypoglycemia occurs, patients should be instructed to seek emergency treatment. Thyrotoxicosis Beta-adrenergic blockade may mask certain clinical signs (e.g., tachycardia) of hyperthyroidism. Abrupt withdrawal of beta blockade might precipitate a thyroid storm; therefore, patients suspected of developing thyrotoxicosis from whom atenolol tablets therapy is to be withdrawn should be monitored closely. (See DOSAGE AND ADMINISTRATION .) Untreated Pheochromocytoma Atenolol tablets should not be given to patients with untreated pheochromocytoma. Pregnancy and Fetal Injury Atenolol can cause fetal harm when administered to a pregnant woman. Atenolol crosses the placental barrier and appears in cord blood. Administration of atenolol, starting in the second trimester of pregnancy, has been associated with the birth of infants that are small for gestational age. No studies have been performed on the use of atenolol in the first trimester and the possibility of fetal injury cannot be excluded. If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to the fetus. Neonates born to mothers who are receiving atenolol tablets at parturition or breastfeeding may be at risk for hypoglycemia and bradycardia. Caution should be exercised when atenolol tablets are administered during pregnancy or to a woman who is breastfeeding. (See PRECAUTIONS: Nursing Mothers .) Atenolol has been shown to produce a dose-related increase in embryo/fetal resorptions in rats at doses equal to or greater than 50 mg/kg/day or 25 or more times the maximum recommended human antihypertensive dose.* Although similar effects were not seen in rabbits, the compound was not evaluated in rabbits at doses above 25 mg/kg/day or 12.5 times the maximum recommended human antihypertensive dose.*

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 tablets and placebo-treated patients than when these reactions were volunteered. Where frequency of adverse effects of atenolol tablets and placebo is similar, causal relationship to atenolol tablets is uncertain. Volunteered (U.S. Studies) Total-Volunteered and Elicited (Foreign + U.S. …

Catecholamine-depleting drugs (e.g., reserpine) may have an additive effect when given with beta-blocking agents. Patients treated with atenolol tablets plus a catecholamine depletor should therefore be closely observed for evidence of hypotension and/or marked bradycardia which may produce vertigo, syncope, or postural hypotension. Calcium channel blockers may also have an additive effect when given with atenolol tablets (see WARNINGS ). Disopyramide is a Type I antiarrhythmic drug with potent negative inotropic and chronotropic effects. Disopyramide has been associated with severe bradycardia, asystole and heart failure when administered with beta-blockers. Amiodarone is an antiarrhythmic agent with negative chronotropic properties that may be additive to those seen with beta-blockers. Beta-blockers may exacerbate the rebound hypertension which can follow the withdrawal of clonidine. …