Atenolol

The selected tablet label covers hypertension, long-term angina due to coronary atherosclerosis, and reduction of cardiovascular mortality in hemodynamically stable patients with definite or suspected acute myocardial infarction. It is not a general label for all arrhythmias or heart-failure treatment.

Use current cardiovascular guidance to decide the indication and duration. The AHA’s chronic-coronary-disease summary does not recommend long-term beta blockade solely to improve outcomes when there has been no MI in the past year, LVEF is above 50%, and there is no other primary indication. Beta blockers or calcium-channel blockers remain options for first-line antianginal therapy. The old tablet label’s suggested 1–3 post-MI years is not a universal contemporary duration.

Acute-MI treatment belongs in monitored coronary care after stabilization, not self-treatment of chest pain. The label’s supporting trial excluded systolic BP below 100 mm Hg, heart rate below 50 bpm, and other beta-blocker contraindications. The profile reviews the oral tablet label; a current injectable product and its supply were not verified, so an IV preparation protocol is not provided.

Individualize to pulse, BP, symptoms, organ function, and concomitant drugs. These adult label regimens do not establish pediatric dosing.

Significant accumulation occurs when CrCl falls below 35 mL/min/1.73 m². Preserve the label’s indexed clearance units rather than substitute another renal estimate without assessment. The label notes that data for corresponding reductions in non-hypertension indications are limited; titrate carefully.

The tablet label describes 25 mg or 50 mg after each hemodialysis session, under hospital supervision because marked BP falls may occur. This is a post-dialysis regimen, not an instruction to take the same dose daily in addition. Confirm timing, dose, and monitoring with the treating team.

In the selected label, patients tolerating the full monitored IV phase receive oral 50 mg 10 minutes after the last IV dose, then another 50 mg 12 hours later; subsequently 100 mg daily or 50 mg twice daily for a further 6–9 days or until discharge. If IV treatment is omitted, eligible patients may receive 50 mg twice daily or 100 mg daily for at least 7 days. These label pathways require specialist assessment and BP/heart-rate/ECG monitoring; stop treatment when clinically significant bradycardia, hypotension, or other adverse effects require it. They are not universal contemporary ACS protocols.

Withdraw gradually with close observation, especially with angina; limit physical activity as advised during withdrawal. The selected label gives no universal numeric taper. Tablets contain single-ingredient atenolol; do not substitute an atenolol/chlorthalidone combination or apply oral directions to an injection.

Sinus bradycardia, heart block greater than first degree, cardiogenic shock, overt cardiac failure, and hypersensitivity to atenolol or product components. The selected label’s overt-failure contraindication does not mean that all beta blockers have identical heart-failure indications.

The selected label’s boxed warning concerns cessation of therapy in coronary disease: abrupt withdrawal can severely worsen angina or precipitate MI and ventricular arrhythmias. Withdrawal requires observation and reduced activity; coronary insufficiency may require prompt reinstitution by the clinician. Unrecognized coronary disease is a reason to avoid sudden cessation even in hypertension treatment.

Bradycardia, hypotension or postural symptoms, cold extremities, fatigue, dizziness, GI symptoms, and wheezing or dyspnea are reported. Postmarketing events include liver-test abnormalities, visual or psychiatric symptoms, sexual dysfunction, skin reactions, and thrombocytopenia. Rates differ between hypertension trials and acute-MI studies; do not generalize one population’s incidence.

Verapamil or diltiazem can cause additive bradycardia, heart block, or ventricular dysfunction. Digoxin, amiodarone, disopyramide, other beta blockers, and catecholamine-depleting drugs such as reserpine warrant careful assessment; hypotension and severe bradycardia may occur.

Beta blockers can worsen rebound hypertension after clonidine cessation. The label advises withdrawing the beta blocker several days before gradual clonidine withdrawal; when replacing clonidine with a beta blocker, delay starting the beta blocker for several days after clonidine has stopped. Coordinate this with atenolol’s coronary-withdrawal warning; do not stop either medicine independently.

Prostaglandin-synthesis inhibitors such as indomethacin may reduce BP-lowering effects; review NSAID use and BP response. Patients with a history of anaphylaxis can have more severe reactions during beta blockade and may respond inadequately to usual epinephrine doses; tell emergency clinicians about atenolol. This does not instruct patients to withhold prescribed emergency epinephrine.

Atenolol crosses the placenta; second-trimester initiation has been associated with small-for-gestational-age infants, and first-trimester fetal risk cannot be excluded. Assess alternatives and maternal benefit rather than assume safety. Atenolol enters breast milk at concentrations exceeding maternal plasma; clinically significant infant bradycardia has been reported. Neonates, premature infants, and infants with impaired kidney function are particularly vulnerable to bradycardia or hypoglycemia; discuss feeding and monitoring with the treating team.

Pediatric safety and effectiveness are not established in the selected label; no pediatric regimen is provided. Older patients have reduced clearance and higher exposure. Start cautiously, assess renal function and clinical response, and consider the greater prevalence of conduction disease, hypotension, and interacting drugs.

Renal elimination drives dose reduction; use the indexed CrCl limits and dialysis instructions above. Atenolol undergoes little or no hepatic metabolism, but the selected label does not supply a validated hepatic-impairment dosing table. Beta-1 selectivity diminishes at higher doses and does not eliminate asthma or COPD risk. Monitor peripheral circulation and glucose risk when relevant.

Atenolol reduces heart rate and cardiac adrenergic stimulation, slows AV-node conduction, and generally lowers myocardial oxygen demand. It has no intrinsic sympathomimetic or membrane-stabilizing activity. At higher doses beta-2 blockade becomes more important; the exact antihypertensive mechanism is not fully established.

Protein binding is low, approximately 6–16%. Clinical beta-blocking and antihypertensive effects of studied 50–100 mg doses can persist at least 24 hours despite a shorter plasma half-life. Renal impairment and older age prolong exposure.

Oral absorption

Approximately 50%

Peak blood level

2–4 hours after ingestion

Elimination half-life

About 6–7 hours with normal renal function

Main elimination

Renal excretion; little or no hepatic metabolism

Check BP and pulse, orthostatic symptoms, angina control, heart-failure symptoms, conduction concerns, and renal function. Use trough BP to assess low-dose 24-hour efficacy. The current AHA hypertension summary supports home BP monitoring integrated with clinician follow-up and comprehensive risk management; avoid assuming a smartwatch reliably measures BP. Assess glucose-related symptoms during fasting or vomiting.

• Take the prescribed dose consistently. Do not stop abruptly or change withdrawal timing without the prescriber.
• Report fainting, severe dizziness, new breathlessness, swelling, wheezing, or very slow pulse. Chest pain or collapse requires urgent assessment.
• Tell clinicians about atenolol before surgery and before starting rate-slowing drugs, clonidine, or regular NSAIDs.
• Hypoglycemia may occur without the usual fast heartbeat; discuss glucose monitoring and sick-day or fasting instructions if relevant.

Overdose can cause severe bradycardia, shock, respiratory impairment, or hypoglycemia and requires emergency evaluation. Current AHA guidance uses vasopressors and high-dose insulin/euglycemia therapy for appropriate life-threatening cases; hemodialysis may be reasonable for severe atenolol poisoning. These are monitored specialist treatments, not home instructions. Do not induce vomiting. Call 911 for collapse or impaired breathing and U.S. Poison Control at 1-800-222-1222 for suspected overdose.

Manufactured by Unique Pharmaceutical Laboratories and distributed by Rising Pharma. These are not the brand Tenormin appearance or NDC.

Strength / form

50 mg film-coated oral tablet

Appearance

Circular, biconvex, white to off-white; scored

Imprint

ATN and 50 on one side; lip-like score on reverse

Package example

Bottle of 100 · NDC 64980-438-01

Reviewed Rising single-ingredient oral tablets: 25, 50, and 100 mg. Other manufacturers can differ in imprint, coating, scoring, or excipients. The tablet label mentions an IV acute-MI phase, but a current injectable product’s preparation, packaging, and supply were not verified here. Combination products and compounded liquids are outside this reference.

Store the selected tablets at controlled room temperature, 20–25°C (68–77°F), in a well-closed, light-resistant container. Follow the actual dispensing container and product instructions; keep away from children.