Salmeterol belongs to the class of medications called long-acting bronchodilators. It is used for the treatment of asthma. It works by opening the airways and making breathing easier. It is used for people 4 years of age and older who are also using inhaled corticosteroids to treat their asthma. These people still experience breakthrough asthma symptoms (coughing, wheezing, tightening of the airways) and require regular use of a short-acting bronchodilator such as salbutamol, terbutaline, or fenoterol.

Salmeterol may also be used for the treatment of chronic obstructive pulmonary disease (COPD).

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

The recommended dose for people four years of age and older is 1 blister (50 µg) used with the Diskus twice daily. This medication must not be used to treat acute symptoms of asthma. For "rescue" purposes, use short-acting medications that start to work quickly such as salbutamol, terbutaline, or fenoterol. Ask your pharmacist to demonstrate the proper administration of the medication for the particular device you are using.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones given here, do not change the way that you are taking the medication without consulting your doctor.

It is very important to take this medication on a regular schedule as prescribed by the doctor. Do not stop taking any of your regularly inhaled medications unless instructed to do so by your doctor. If you miss a dose of this medication, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and continue with your regular schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Each dose of dry powder of microfine salmeterol for inhalation contains 50 µg of salmeterol. Nonmedicinal ingredient: lactose.

Do not use this medication if you:

• are allergic to salmeterol or any ingredients of this medication
• are allergic to lactose or milk protein
• are not using an inhaled corticosteroid (e.g., budesonide, fluticasone)
• have abnormal heart rhythms associated with fast heart rates
• have asthma and are not also using an inhaled corticosteroid

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

• agitation
• coughing or other bronchial irritation
• diarrhea
• dizziness or lightheadedness
• dryness or irritation of mouth or throat
• fast heartbeat
• fatigue
• fever
• headache
• increased frequency of cold symptoms or sinus infections
• irritation of throat or mouth
• muscle cramps or twitching
• nausea
• nervousness
• palpitations (pounding heart beat)
• restlessness
• trembling
• trouble sleeping
• vomiting

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not seek medical attention.

Check with your doctor immediately if any of the following side effects occur:

• feeling of choking, irritation, or swelling in throat
• fast or irregular heart beat that does not go away
• increased shortness of breath, tightness in chest, or wheezing
• high blood pressure (e.g., headache or severe dizziness)
• joint pain
• signs of low potassium levels in the blood (e.g., weakness, fatigue, muscle cramps, irregular heartbeat)
• symptoms of high blood sugar (e.g., frequent urination, increased thirst, excessive eating, unexplained weight loss, poor wound healing, infections, fruity breath odour)

Stop taking the medication and seek immediate medical attention if any of the following occur:

• signs of a serious allergic reaction (e.g., abdominal cramps, difficulty breathing, nausea and vomiting, or swelling of the face and throat)
• sudden worsening of shortness of breath and wheezing shortly after using salmeterol

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Asthma-related deaths: When used alone for asthma treatment for children, salmeterol has been linked to an increase in asthma-related deaths and asthma-related hospitalizations. Salmeterol must always be used in combination with an inhaled corticosteroid. If you experience worsening symptoms or your "rescue" medications are not as effective as usual, contact your doctor or seek medical attention immediately.

Bronchospasm: Occasionally, inhaled medications may cause the airways to spasm and close up, making breathing even more difficult (bronchospasm). If you experience increased difficulty breathing after using a dose of salmeterol, seek immediate medical attention.

Diabetes: Salmeterol may cause an increase in blood sugar levels. If you have diabetes, you may find it necessary to monitor your blood sugar more frequently while using this medication. If you have diabetes or are at risk for developing diabetes, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Heart rhythm: Beta-agonists such as salmeterol can cause changes to the normal rhythm of the heart, including an irregular heartbeat called QT prolongation. QT prolongation is a serious life-threatening condition that can cause fainting, seizures, and sudden death.

Salmeterol can cause a fluttering of the heartbeat (atrial fibrillation) or rapid heart beat, increased blood pressure, chest pain, and decreased oxygen reaching the heart muscle.

If you are at risk for heart rhythm problems (e.g., people with heart failure, angina, low potassium or magnesium levels), discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Liver function: The liver is responsible for removing salmeterol from the body. Decreased liver function or liver disease can cause salmeterol to build up in the body, causing side effects. If you have decreased liver function, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Monitoring asthma: Talk to your doctor about ways for you to monitor your asthma at home, such as a peak flow meter. Peak flow metres measure the amount of air you can expel in a short time and can help you identify when your asthma might be flaring up even before you begin to experience symptoms.

Prevention only: Salmeterol should not be used to treat acute symptoms (as a "rescue" medication). It is meant for prevention purposes only. Salmeterol should be taken along with other medications called inhaled corticosteroids. Short-acting medications such as salbutamol, terbutaline, or fenoterol are required for relief of breathing symptoms as instructed by your doctor and should be available at all times.

Seizures: If you have a history of epilepsy or medical conditions that increase the risk of seizures, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Thyroid disease: If you have an overactive thyroid gland, you may be more sensitive to the effects of salmeterol. If you have thyroid disease, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Worsening symptoms: If you find you need to use your short-acting ("rescue") inhaler more often or if your condition seems to worsen, call your doctor. If you have not been given instructions beforehand, contact your doctor immediately about what to do if any of the following situations occur (they may be signs of seriously worsening asthma):

• decreased effectiveness of short-acting, inhaled bronchodilators such as salbutamol, terbutaline, or fenoterol (less than 4 hours of relief)
• need for more inhalations than usual of short-acting, inhaled bronchodilators
• peak flow meter showing results in the below-normal range

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: It is not known if salmeterol passes into breast milk. If you are breast-feeding and are taking this medication, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using salmeterol have not been established for children younger than 4 years of age.

There may be an interaction between salmeterol and any of the following:

• amiodarone
• amphetamines (e.g., dextroamphetamine, lisdexamfetamine)
• antipsychotics (e.g., chlorpromazine, clozapine, haloperidol, loxapine, olanzapine, quetiapine, risperidone)
• aprepitant
• atomoxetine
• "azole" antifungals (e.g., itraconazole, ketoconazole, voriconazole)
• beta-blockers (e.g., metoprolol, propranolol)
• betahistine
• caffeine
• cannabis
• cobicistat
• conivaptan
• decongestant cold medications (e.g., phenylephrine, pseudoephedrine)
• decongestant eye drops and nose sprays (e.g., naphazoline, oxymetazoline, xylometazoline)
• diltiazem
• disopyramide
• diuretics (e.g., hydrochlorothiazide, furosemide)
• dronedarone
• epinephrine
• fast-acting bronchodilators (e.g., salbutamol, terbutaline)
• grapefruit juice
• HIV protease inhibitors (e.g., atazanavir, indinavir, ritonavir, saquinavir)
• letermovir
• macrolide antibiotics (e.g., clarithromycin, erythromycin)
• methadone
• methylphenidate
• mifepristone
• modafinil
• monoamine oxidase inhibitors (MAOIs; e.g., moclobemide, phenelzine, rasagiline, selegiline, tranylcypromine)
• nabilone
• other long-acting bronchodilators (e.g., formoterol, other medications containing salmeterol)
• ozanimod
• procainamide
• quinidine
• quinine
• quinolone antibiotics (e.g., ciprofloxacin, ofloxacin, sparfloxacin)
• sotalol
• stiripentol
• theophyllines (e.g., aminophylline, oxtriphylline, theophylline)
• tricyclic antidepressants (e.g., amitriptyline, clomipramine, desipramine, trimipramine)
• tyrosine kinase inhibitors (e.g., ceritinib, imatinib, lapatinib, pazopanib, sunitinib)
• verapamil

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.