BMA Concise Guide to Medicine & Drugs

Salmeterol

Brand name Serevent

Used in the following combined preparation Seretide

QUICK REFERENCE

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

Salmeterol is a sympathomimetic bronchodilator used to treat conditions, such as asthma, chronic obstructive pulmonary disease (COPD), and bronchospasm, in which the airways become constricted. Its advantage over salbutamol (opposite) is that it is longer acting.

Salmeterol relaxes the muscle surrounding the airways in the lungs but, because of its slow onset of effect, it is not used for immediate relief of symptoms of asthma. It is prescribed to prevent attacks, however, and can be helpful in preventing night-time asthma.

Salmeterol should always be used in combination with inhaled or oral corticosteroids. Taken by inhalation, the drug is delivered directly to the airways. This allows smaller doses to be taken and reduces the risk of adverse effects.

INFORMATION FOR USERS

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

How taken/used Inhaler, powder for inhalation.

Frequency and timing of doses 2 x daily.

Dosage range 100–200mcg daily.

Onset of effect 10–20 minutes.

Duration of action 12 hours.

Diet advice None.

Storage Keep in original container at room temperature out of the reach of children.

Missed dose Take as soon as you remember. If your next dose is due within 4 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

Side effects of salmeterol are usually mild. Tremor is the most common; discuss with your doctor if it is severe. Less commonly, palpitations, headache, or muscle cramps may occur; if so, consult your doctor. Rarely, wheezing or breathlessness may worsen after using the inhaler (paradoxical bronchospasm); if this happens, stop using the drug and contact your doctor immediately.

INTERACTIONS

Corticosteroids, theophylline, and diuretics There is an increased risk of low blood potassium levels when high doses of salmeterol are taken with these drugs.

Other sympathomimetics may increase the effects of salmeterol, thereby also increasing the risk of adverse effects.

Digoxin Salmeterol may cause low potasssium levels in the blood, which increases the risk of digoxin toxicity.

Protease inhibitors (e.g. ritonavir, saquinavir, and telaprevir) increase the risk of abnormal heart rhythms when used with salmeterol.

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. Benefits of treatment usually outweigh risk that mother’s worsening asthma has on developing baby. 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. Not recommended for children under 4 years.

Over 60 No special problems.

Driving and hazardous work No special problems.

Alcohol No known problems.

PROLONGED USE

Salmeterol is intended to be used long-term together with an inhaled corticosteroid. The main problem comes from using combinations of anti-asthma drugs with or without diuretics, leading to low blood potassium levels.

Monitoring Periodic blood tests are usually carried out to monitor potassium levels.