BMA Concise Guide to Medicine & Drugs

Salbutamol

Brand names Airomir, Asmasal, Salamol, Ventmax, Ventodisks, Ventolin, and others

Used in the following combined preparation Combivent

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Drug group Bronchodilator, drug to treat asthma, and drug used in premature labour

Overdose danger rating Low

Dependence rating Low

Prescription needed Yes

Available as generic Yes

GENERAL INFORMATION

Salbutamol is a sympathomimetic bronchodilator used to treat conditions such as asthma, chronic obstructive pulmonary disease (COPD), and bronchospasm, in which the airways become constricted. Although it can be taken by mouth, inhalation is more effective because the drug is delivered directly to the airways, thus giving rapid relief, allowing smaller doses, and causing fewer side effects. If you need to use inhaled salbutamol more than twice a week or have to use it at night, you will probably also be prescribed an inhaled corticosteroid to improve control of your asthma.

Compared to some similar drugs, salbutamol has little stimulant effect on the heart rate and blood pressure, making it safer for people with heart problems or high blood pressure. Because salbutamol relaxes the muscle of the uterus, it is also used to prevent premature labour.

INFORMATION FOR USERS

Your drug prescription is tailored for you. Do not alter dosage without checking with your doctor.

How taken/used Tablets, SR tablets, SR capsules, liquid, injection, inhaler, nebules for nebulizer, powder for inhalation.

Frequency and timing of doses 3–4 x daily (tablets/liquid); 2 x daily (SR preparations); 1–2 inhalations 3–4 x daily (inhaler); up to 4 x daily (nebules).

Dosage range 8–16mg daily (by mouth); 400–800mcg daily (inhaler); 2.5–20mg daily (nebules).

Onset of effect Within 30–60 minutes (by mouth); within 5–15 minutes (inhaler/nebules).

Duration of action Up to 8 hours (tablets); up to 6 hours (inhaler); up to 12 hours (SR preparations).

Diet advice None.

Storage Keep in original container at room temperature out of the reach of children. Protect from light. Do not puncture or burn inhalers.

Missed dose Take as soon as you remember if you need it. If your next dose is due within 2 hours, take a single dose now and skip the next.

Stopping the drug Do not stop the drug without consulting your doctor; symptoms may recur.

Exceeding the dose An occasional unintentional extra dose is unlikely to be a cause for concern. But if you notice any unusual symptoms, or if a large overdose has been taken, notify your doctor.

POSSIBLE ADVERSE EFFECTS

Muscle tremor (which particularly affects the hands), anxiety, and restlessness are the most common adverse effects of salbutamol. Discuss with your doctor if they are severe or if you develop headache or muscle cramps. If palpitations occur, stop taking the drug and consult your doctor. Rarely, wheezing or breathlessness may worsen immediately after using the inhaler (paradoxical bronchospasm); if so, stop using the drug and contact your doctor immediately.

INTERACTIONS

Theophylline, corticosteroids, and diuretics There is a risk of low potassium levels in blood occurring if this drug is taken with salbutamol.

Other sympathomimetic drugs may increase the effects of salbutamol, thereby also increasing the risk of adverse effects.

Digoxin Salbutamol may cause low potassium levels, increasing the risk of digoxin toxicity. Salbutamol by mouth or injection can reduce digoxin levels.

Beta blockers Drugs in this group may reduce the action of salbutamol.

SPECIAL PRECAUTIONS

Be sure to tell your doctor if:

· You have heart problems.

· You have high blood pressure.

· You have an overactive thyroid gland.

· You are taking other medicines.

Pregnancy No evidence of risk when used to treat asthma, or to treat or prevent premature labour. Discuss with your doctor.

Breast-feeding The drug passes into the breast milk, but at normal doses adverse effects on the baby are unlikely. Discuss with your doctor.

Infants and children Reduced dose necessary.

Over 60 Increased likelihood of adverse effects. Reduced dose may therefore be necessary.

Driving and hazardous work Avoid such activities until you have learned how salbutamol affects you because the drug can cause tremors.

Alcohol No known problems.

PROLONGED USE

No problems expected. However, you should contact your doctor if you find you are needing to use your salbutamol inhaler more than usual. Failure to respond to the drug may be a result of worsening asthma that requires urgent medical attention.

Monitoring Periodic blood tests for potassium may be needed in people on high-dose treatment with salbutamol combined with other asthma drugs and/or diuretics.