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Hypertension & Stroke



Brand Names: Tenormin
Drug Class: Beta-blocker
Available in: Tablets (Injection is for hospital use only.)
Available Without a Prescription? No
Available as a Generic? Yes

Side Effects

Serious: Depression, shortness of breath, wheezing, slow heartbeat (especially less than 50 beats per minute), chest pain or tightness, swelling of the ankles, feet, and lower legs. If you experience such symptoms, stop taking atenolol and call your doctor immediately.

Common: Decreased sexual ability; decreased ability to engage in usual physical activities or exercise; dizziness or lightheadedness, especially when rising suddenly from a sitting or lying position; drowsiness, fatigue, or weakness; insomnia.

Less Common: Anxiety, irritability; constipation; diarrhea; dry eyes; itching; nausea or vomiting; nightmares or intensely vivid dreams; numbness, tingling, or other unusual sensations in the fingers and toes; abdominal pain; nasal congestion.

Principal Uses

To treat mild to moderate high blood pressure and to treat angina; also used to prevent or control heartbeat irregularities (arrhythmias). The injectable form is used in hospitals to treat heart attack.

How the Drug Works

Atenolol slows the rate and force of contraction of the heart by blocking certain nerve impulses, thus reducing blood pressure. By modifying nerve impulses to the heart, the drug also helps stabilize heart rhythm.


50 to 100 mg, once a day. Smaller doses may be recommended for elderly patients or for those with impaired kidney function.

Onset of Effect

Oral: 1 to 2 hours; the full therapeutic effect may take 1 to 2 weeks. Injectable: Within 10 minutes.

Duration of Action

Up to 24 hours.

Dietary Advice

Take atenolol on an empty stomach. Avoid alcohol and caffeine.


Store in a tightly sealed container away from heat and direct light.

If You Miss a Dose

Take it as soon as you remember. If it is within 4 hours of the next scheduled dose, skip the missed dose and resume your regular schedule. Do not double the next dose.

Stopping the Drug

Suddenly stopping atenolol may cause serious health problems. Slow reduction of the dose over a period of 2 to 3 weeks is advised, under a doctor’s careful supervision.

Prolonged Use

Therapy with atenolol may be lifelong; prolonged use may be associated with an increased risk of side effects.


Over 60: Adverse reactions may be more likely and more severe in older patients; a reduction in dosage may be warranted.

Driving and Hazardous Work: In rare cases atenolol may impair your ability to drive or operate machinery safely or perform hazardous work. Use caution, especially soon after beginning therapy.

Alcohol: Drink in moderation if at all. Alcohol may interact with the drug and cause a dangerous drop in blood pressure.

Pregnancy: Discuss with your doctor the relative risks and benefits of using this drug while pregnant.

Breast Feeding: Avoid or discontinue the use of atenolol while nursing.

Infants and Children: Proper dose will be determined by pediatrician.

Special Concerns: Use of the drug should be considered as only one element of a comprehensive therapeutic program that includes weight control, smoking cessation, regular exercise, and a healthy low-salt, low-fat diet.


Symptoms: Slow heartbeat; severe dizziness, lightheadedness or fainting; rapid or irregular heartbeat; difficulty breathing; extreme weakness; seizures; confusion; coma.

What to Do: Call your doctor, emergency medical services (EMS), or the nearest poison control center immediately.

Drug Interactions

Consult your doctor if you are taking amphetamines, oral antidiabetic drugs, asthma medication (such as aminophylline or theophylline), calcium channel blockers, clonidine, guanabenz, halothane, allergy shots, insulin, MAO inhibitors, reserpine, or other beta-blockers.

Food Interactions

None known.

Disease Interactions

Atenolol should be used with caution in people with diabetes, especially insulin-dependent diabetes, since the drug may mask symptoms of hypoglycemia. Consult your doctor for specific advice if you have allergies or asthma, heart or blood vessel disease (including heart failure and peripheral vascular disease), irregular (slow) heartbeat, hyperthyroidism, myasthenia gravis, psoriasis, respiratory problems such as bronchitis or emphysema, kidney or liver disease, or a history of mental depression.


From The Johns Hopkins Consumer Guide to Drugs. You can order this book now on our secure server.


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Hypertension & Stroke

The Hypertension & Stroke White Paper from The Johns Hopkins White Papers series is an annual, in-depth report written by Hopkins physicians.

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