Along with its needed effects, salmeterol may cause some unwanted or undesirable effects. Often, salmeterol users who use their medication properly, never experience any unwanted effects. The severity and duration of these effects are dependant on many factors including duration of therapy, dose, route of administration and individual response.Possible unwanted effects include:

• headache
• feeling a little shaky
• slight palpitations (awareness of heart beat)

Uncommon:

• increased heart rate
• increase in the amount of sugar (glucose)
• dizziness
• nausea
• muscle cramps
• trouble sleeping
• weakness
• drowsiness
• flushing

Rare:

• restlessness
• irritability
• vertigo (whirling sensation)
• unusual taste
• chest discomfort
• angina (chest pain)

Many of these unwanted effects, especially the most common ones, may disappear with continued use. Check with the doctor or pharmacist if any of them continue or become bothersome.

Salmeterol is a long-acting bronchodilator that acts at specific receptors called beta2-adrenergic receptors. It works by relieving spasm or narrowing in the small air passages in the lungs causing chest tightness and wheezing. This helps to open up the airways and makes it easier for air to get in and out of the lungs. When it is taken regularly, it helps the small air passages stay open.

• In asthma, salmeterol must be used together with an appropriate dose of inhaled corticosteroid and salmeterol should never be used as rescue medication.
• Maximum benefit cannot be achieved if the device is not used correctly. Even if you have used the device before, you should have your technique reassessed by your pharmacist and read the patient instructions that are provided with each product.
• Salmeterol's bronchodilating effect lasts 12 hours. It should be used on a regular basis, every morning and evening (every 12 hours) and never more frequently than this. Breakthrough symptoms should be treated with a short-acting (rescue) bronchodilator.
• If your rescue medication isn't working as well as it used to, or if you need more inhalations than usual to control breakthrough symptoms, your asthma may be worsening and your condition should be reassessed by your doctor.
• Never adjust doses of salmeterol or any other asthma medications you are taking without consulting the doctor.
• Using 2 or more inhaled medications can lead to confusion. Ensure that you know what each one is for and when they should be used.
• Salmeterol is intended for long-term treatment and should not be started in people whose asthma is worsening or unstable.

Drug Interactions: Be sure to tell your doctor and pharmacist about any prescription or over-the-counter medications you are taking in order to avoid any potential drug interactions. The following drugs and drug classes have been known to interact with salmeterol:

• MAO (monoamine oxidase) inhibitors (e.g. phenelzine, tranylcypromine)
• tricyclic antidepressants (e.g. amitriptyline)
• some beta-blockers (e.g. propranolol)
• other bronchodilators

Use is not recommended in the following situations:

• allergy to salmeterol or any component of the preparation
• allergy to lecithin, soya or related products (e.g. soyabeans), milk or lactose
• cardiac arrhythmia (irregular hear beat) associated with tachycardia (rapid heart rate)
• people whose asthma is managed by occasional use of short- acting bronchodilators
• children under 4 years of age

Caution recommended in the following situations:

• high blood pressure
• diabetes
• heart disease
• seizures (history)
• elderly
• sensitivity to sympathomimetics (drugs that stimulate the central nervous sysytem)

Use in pregnancy: Data is limited. Consult your doctor or pharmacist before use.
Use while breastfeeding: Data is limited.  Consult your doctor or pharmacist before use.