Atenolol (Tenormin and others)

How Medicare covers it

Part D (tablets taken at home). Part A during a covered inpatient stay. No Part B clinician-administered form in the CMS Part B spending file.

What it treats

Treats high blood pressure (hypertension); treats angina pectoris (chest pain from coronary artery disease) for long-term management; and is used in patients with definite or suspected acute myocardial infarction (heart attack) to reduce cardiovascular mortality, starting with intravenous treatment in the hospital.

What it is for, in depth

Atenolol is a beta blocker used for heart and blood pressure problems. The label says it treats high blood pressure, called hypertension. It also treats angina pectoris, which is chest pain from coronary artery disease, for long-term management. It is also used in patients with definite or suspected acute myocardial infarction, which is a heart attack, to reduce cardiovascular mortality, meaning death from heart and blood vessel causes, starting with intravenous treatment in the hospital. It works by blocking beta-1 receptors in the heart, slowing the heart rate and reducing how hard the heart works, which lowers blood pressure and reduces the heart's need for oxygen. Atenolol comes as oral tablets taken once a day. The formulary lists tablets in three strengths, and the label describes starting treatment once daily and raising the dose if needed. People should not stop it suddenly without medical advice.

How it works

Atenolol is a beta-blocker. It blocks beta-1 receptors in the heart, slowing the heart rate and reducing how hard the heart works, which lowers blood pressure and reduces the heart's need for oxygen.

How it is taken

Tablets once a day. For hypertension, the starting dose is 50 mg once daily, increasing to 100 mg once daily if needed; doses above 100 mg a day are unlikely to add benefit. For angina, the starting dose is 50 mg once daily, which may be raised to 100 mg, and some patients need 200 mg once daily. Do not stop it suddenly — see the boxed warning.

Common side effects

In studies of patients with hypertension, reported effects included slow heartbeat (bradycardia), cold extremities, dizziness, postural hypotension (blood pressure drop on standing), leg pain, vertigo, lightheadedness, tiredness and fatigue, lethargy, drowsiness, depression, dreaming, diarrhea, nausea, wheeziness, and shortness of breath. Most effects were mild and transient.

Serious warnings

Atenolol can worsen heart failure, cause heart block or a severely slow heartbeat, and trigger wheezing or breathing problems. In patients with diabetes it can mask some warning signs of low blood sugar. Patients with a history of severe allergic reactions may react more strongly to allergens while taking beta-blockers and may respond less to the usual dose of epinephrine.

Boxed warning

BOXED WARNING — stopping suddenly: Patients with coronary artery disease should be advised against abruptly discontinuing atenolol. Severe worsening of angina, myocardial infarction (heart attack), and ventricular arrhythmias have been reported in angina patients after abrupt discontinuation of beta-blocker therapy. When discontinuation is planned, taper the dose, watch the patient carefully, and limit physical activity; if angina worsens or acute coronary insufficiency develops, restart atenolol promptly, at least temporarily.

Who should be careful

Do not take it with sinus bradycardia, heart block greater than first degree, cardiogenic shock, or overt cardiac failure, or if you are allergic to atenolol. Use with care in asthma or other breathing disease, diabetes, heart failure that is compensated, and before surgery; tell your doctor about all of these.

Major interactions

Catecholamine-depleting drugs such as reserpine can add to atenolol's effect (watch for low blood pressure and marked slow heartbeat). Calcium channel blockers can also add to its effect. Disopyramide and amiodarone have negative effects on heart rate and contraction that may add to beta-blocker effects. If clonidine is being stopped, the beta-blocker should be withdrawn several days before clonidine is gradually withdrawn to avoid rebound hypertension. NSAIDs such as indomethacin may reduce the blood-pressure-lowering effect of beta-blockers.

Why it is in its tier

Atenolol is most often placed on Tier 1. It is listed by 100.0% of Part D plans, and 98.13% of listing plans place it on Tier 1, which is the most common tier by an overwhelming majority. Tier 1 is the lowest, preferred generic tier, often $0-$15, so cost share is the lowest a plan offers. That placement fits what the data show: atenolol is a long-used generic tablet with no brand form driving placement in this package. CMS dashboard data show average spending per beneficiary of $31.74, labeled here as CMS program average spending, not a copay, which is low and supports the lowest generic tier. Individual plans vary, and readers should check their own plan's formulary.

Sources

• ATENOLOL TABLET [PD-RX PHARMACEUTICALS, INC.] — DailyMed
• MedlinePlus — National Library of Medicine
• MedlinePlus — Atenolol

What official patient guides say

Atenolol comes as a tablet to take by mouth, taken once or twice a day at around the same time or times every day. Keep taking it even if you feel well, and do not stop taking it without talking to your doctor. Unless your doctor tells you otherwise, you can continue your normal diet. If you miss a dose, take it as soon as you remember, but if it is almost time for the next dose, skip the missed dose and keep your regular schedule — do not take a double dose. Keep it in the container it came in, tightly closed, at room temperature and away from extra heat and moisture (not in the bathroom), and out of reach of children.

Source: MedlinePlus — Atenolol

Part D formulary coverage

Source: CMS Prescription Drug Plan Formulary, Pharmacy Network, and Pricing Information Files — Monthly file 2026-10-15 (plan year 2027), file 2027_20261008.zip (data.cms.gov dataset ed1496ea-23e7-41f1-9292-172fa842ccfb): basic drugs formulary file + plan information file, both dated 20261031 inside the zip; downloaded and aggregated 2026-10-30. Medication RxCUI sets resolved through the NLM RxNav (RxNorm) API.

What you pay

Without insurance, the cash benchmark is $0.0371 per unit (ATENOLOL 100 MG TABLET) — about $1.11 for 30 units. NADAC benchmark — the average price pharmacies pay (CMS, as of 2026-11-04). Pharmacy shelf prices vary.

A tier is not a price; what you pay depends on your plan, pharmacy, and benefit stage; Extra Help or Medicaid can lower it further.

Sources: CMS Plan Benefit Package + formulary data; CMS NADAC · Checked 2026-11-07

Coverage by plan and tier

Of the 5,495 Medicare drug plans we track for 2027, 5,495 list Atenolol (Tenormin and others) — 100% of plans. Most of those plans put it on Tier 1: 5,392 plans, 98.1% of the plans that list it. Other plans place it on Tier 2 (91 plans) or Tier 6 (12 plans). For example: Aetna Medicare Dual Extra (HMO D-SNP) puts it on Tier 1; Aetna Medicare Dual Extra Care (PPO D-SNP) puts it on Tier 1; Aetna Medicare Value Plus (PPO) puts it on Tier 1. You can compare these plans side by side on our Medicare Advantage hub. A tier is not a price. What you pay also depends on whether you have met your plan's deductible, whether the drug costs a flat copay or a share of the price, and whether you get Extra Help or Medicaid.

Read next

• Part D in 2027: The $700 Deductible, the $2,400 Cap, and the $35 Insulin Rule
• Extra Help in 2027: Lower Drug Copays and Who Qualifies
• Checking Medicare Savings Programs and Extra Help

Part D spending averages (2024)

Source: CMS Medicare Part D Spending by Drug (Drug Spending Dashboard), release RY26 P04 V10, data through 2024 (DSD_PTD_RY26_P04_V10_DY24_BGM.csv), downloaded 2026-10-30

Companies covering this drug

Part D and Medicare Advantage plan sponsors that list this drug on a formulary, 50 at a time.