Generic name: Atenolol.

Tenormin is a beta-adrenergic blocking agent (beta-blocker). Beta-blockers decrease the workload of the heart and help regulate the heartbeat. 

Quick Facts About Tenormin


Used in the treatment of high blood pressure, angina (chest pain), and heart attack. Also prescribed for alcohol withdrawal, prevention of migraine, and anxiety.

Tenormin Dosage

May take with or without food, per doctor’s instructions. Take exactly as prescribed, even if symptoms disappear. If taking once a day, try not to miss dose; condition may worsen if not taken regularly. Should not be stopped suddenly, can increase chest pain; dosage must be reduced gradually.

  • Usual adult dose: 50 milligrams per day in 1 dose, taken alone or with a diuretic. Will see full effect in 1 to 2 weeks. Doctor may increase up to 100 milligrams per day maximum. Angina — 50 milligrams per day in 1 dose, taken alone or with a diuretic. Will see full effect in 1 week. Doctor may increase up to 100 milligrams per day maximum; dose is individualized. For heart attack — dose is individualized. Seniors — dose is individualized.
  • Usual child dose: not generally prescribed for children.
  • Missed dose: take as soon as possible, unless within 8 hours of next dose. In that case, do not take missed dose; go back to regular dose. Do not double doses.

Tenormin Side Effects

Overdose symptoms:

bronchospasm, changes in breathing, congestive heart failure, low blood pressure, low blood sugar, slow heartbeat, sluggishness, wheezing. If you suspect an overdose, immediately seek medical attention.

More common side effects: dizziness, fatigue, nausea, slow heartbeat

Less common or rare Tenormin side effects: depression, diarrhea, difficult or labored breathing, dizziness upon standing up, drowsiness, headache, heart failure, impotence, light-headedness, low blood pressure, penile deformity, psoriasis-like rash, red or purple spots on the skin, rapid heartbeat slow heartbeat, sluggishness, temporary hair loss, tiredness, vertigo, wheezing, worsening of psoriasis.


Inform your doctor before combining Tenormin with:

ampicilfin (Omnipen), calcium-containing antacids such as Turns, calcium-blocking blood pressure drugs such as Calan and Cardizem, certain blood pressure drugs such as reserpine (Diupres), epinephrine (Epipen), insulin, oral diabetes drugs such as Micronase, quinidine (Quinidex).

No known food/other substance interactions. 

Special Cautions

If pregnant or planning to become pregnant inform your doctor immediately. May cause harm to a developing fetus. Appears in breast milk; could affect a nursing infant

Dose is individualized for seniors.

Not generally prescribed for children.

  • Do not take if you have: heart failure, inadequate blood supply to the circulatory system (cardiogenic shock) heart block (conduction disorder), severely slow heart beat.
  • With high blood pressure, must be taken regularly to be effective.
  • Can cause heartbeat to become too slow.
  • Use with caution if you have: asthma, coronary artery disease, kidney disease, history of severe congestive heart failure, seasonal allergies or other bronchial conditions.
  • May mask the symptoms of low blood sugar or alter blood sugar levels.
  • Notify your doctor or dentist in a medical emergency or before surgery.


HealthSurvey.org provides accurate and independent information prescription pills, over-the-counter medicines and natural products. This material is provided for educational purposes only and is not intended for medical advice, diagnosis or treatment. If you have questions about  dosage, or Tenormin side effects, please contact your healthcare provider