Salmeterol is a bronchodilator. It relaxes the airway muscles to improve ease of breathing. It is used to prevent asthma attacks and exercise-induced bronchospasm. It is also used to treat COPD. Salmeterol should not be given to patients under 4.

Don't use this drug longer than the amount of time your doctor prescribes you. Don't use more medicine than prescribed per dose. Before using this drug, inform your doctor of your medical history, other medications you take, and if you become pregnant or breast-feed. Contact your doctor if symptoms don’t improve within a week. The Serevent Diskus device should not be used with a spacer. Use regularly for the most benefit. Do not stop using unless approved by your doctor. Do not stop using a steroid if you also take a steroid. Store away from moisture, sunlight, and heat. Do not clean or disassemble the Diskus device. Dispose of it 6 weeks after the foil pouch has been open or if the dose shows zero, whichever happens first. If you miss a dose, take your medication as soon as you remember, and then wait 12 hours until your next dose. Skip the missed dose if it’s almost time for your next dose.

Do not use for an asthma attack that has already begun. Salmeterol inhalation used to treat asthma must be used together with another long-term asthma control medication; this is especially important for children and teens. Don’t use another form of salmeterol, such as Advair, or a similar inhaled bronchodilator without your doctor’s approval. Do not blow into the device or get it wet.

Find emergency medical attention if you suspect an overdose or allergic reaction. Also contact medical help immediately if your asthma medications do not work well, as this can be a sign of an early serious asthma attack. Contact your doctor if you have a serious reaction, such as: worsening asthma symptoms, breathing issues, muscle cramps, tremors, insomnia, chest pain, fast/irregular pulse, lightheadedness, seizures, symptoms of low potassium, or symptoms of high blood sugar. Other side effects may include: flu symptoms, headache, joint/muscle pain, and congestion. This medication may interact with other drugs, such as antidepressants, antibiotics, and hepatitis C medications.