Meds and you

Updated 11 February 2013


Atenolol is the active ingredient of Adco-Atenolol, B-Block, Bio-Atenolol, Hexa-Blok, Sandoz Atenolol, Ten-Bloka, Tenopress and Tenormin.


Atenolol is the active ingredient of Adco-Atenolol, B-Block, Bio-Atenolol, Hexa-Blok, Sandoz Atenolol, Ten-Bloka, Tenopress and Tenormin.

Atenolol is also one of multiple active ingredients found in Adco-Loten, Sandoz Co-Tenidone, Tenchlor and Tenoretic (all atenolol + chlorthalidone).

General information

Atenolol is a beta blocker indicated for the treatment of high blood pressure, the heart beating too fast, irregular heart rhythms or chest pain (angina). It does not cure any of these conditions, but keeps them under control, and is therefore prescribed to be taken long term.

For atenolol to be effective, it has to be taken regularly, even if you do not notice an immediate effect. Blood pressure declines gradually and it may take a few weeks before you get the full benefit.

Although atenolol is a cardioselective beta blocker and therefore less likely to affect the airways, it may still provoke breathing difficulties due to its effect on receptors in the lungs - If you suffer from asthma or other respiratory conditions, atenolol should be taken with caution. You may also find strenuous activities more difficult, partly because of the drug's effect on the lungs, and partly because it reduces heart rate.

Beta blocking drugs may also reduce blood supply to the limbs en extremities and may therefore cause cold hands and feet. Some men may therefore also experience temporary impotence when taking atenolol.

Atenolol may be prescribed after a heart attack to protect the heart from further damage.

How does Atenolol work?

Atenolol reduces the stimulating effect of noradrenalin. As a result, it lowers the force and speed at which the heart is beating. This assists in stabilising fast and abnormal heart rhythms, reduce chest pain and lowers blood pressure.

Fast facts

Drug schedule: Schedule 3

Available as: Tablets

What does it do? Atenolol treats high blood pressure, irregular heart rhythms and chest pain

Overdose risk: Medium

Dependence risk: Low

Available as a generic? Yes

Available on prescription only? Yes

User information

Onset of effect: Within 4 hours

Duration of action: Up to 30 hours

Dietary advice: Atenolol should preferably be taken on an empty stomach. It should not be taken concurrently with caffeine and alcohol.

Stopping this medicine: Atenolol should never be stopped suddenly after prolonged use. This may markedly increase blood pressure, cause chest pain and may cause fast or irregular hearth rhythms. A heart attack may even be provoked. When treatment with atenolol needs to be stopped, the dosage should be gradually reduced, preferably over a period of 2 to 3 weeks, under medical supervision.

Prolonged use: No special problems foreseen.

Special precautions

Consult your doctor before using this drug if:

  • you suffer from asthma or any other respiratory condition,
  • you have had severe congestive heart failure or any other heart condition in the past,
  • you have a known kidney disease,
  • you have diabetes. Atenolol may mask some of the warning signs of low blood sugar, such as a fast heart rate, and
  • you have a medical emergency, or before you have any surgery.

Pregnancy: Avoid. Potential risk to the foetus has been reported. Consult your doctor before use, or if you are planning to fall pregnant.

Breastfeeding: Avoid. This medication is passed through breast milk and may affect your baby adversely. Consult your doctor before use.

Porphyria: This medication is safe to use.

Infants and children: The safety and efficacy of atenolol have not been established in children.

Elderly: Lower doses may be necessary depending on health.

Driving and hazardous work: Caution is advised, as use of this medication may lead to dizziness, light-headedness and/or sedation. Avoid such activities until you know how it affects you.

Alcohol: No special precautions need to be taken.

Possible side effects

Side effect


Consult your doctor



Only if severe

In all cases




Dizziness/ tiredness/ weakness












Chest pain or tightness



Difficulty breathing/ shortness of breath



Swelling of ankles




Drug interactions:

Nonsteroidal anti-inflammatory drugs (NSAIDs) like ibuprofen

May reduce blood pressure lowering effect

Certain blood pressure medications

Severe low blood pressure or slow heart rate may occur

Certain drugs for malaria/malaria prevention

Risk of serious heart problems may be increased


Increase potential for atenolol toxicity

Certain over-the-counter cold and flu remedies

Risk of severe high blood pressure


May decrease atenolol 's effectiveness


Severe high blood pressure may occur

Disease interactions

Contact your doctor before use in case of heart block or a severely slow heartbeat, if you suffer from asthma or any other respiratory condition, if you have had severe congestive heart failure in the past, if you have known liver or kidney disease, or if you have diabetes. Symptoms of Raynaud's syndrome and myasthenia gravis may be exacerbated by treatment with atenolol.

Overdose action

Seek immediate medical advice in all cases.

Recommended dosage

Adults: 25 - 100mg once a day

This material is not intended to substitute medical advice, but is for informational purposes only. Please consult a physician for specific treatment and recommendations.


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