Asthma:

For patients 12 years of age and older, the usual dose is:
One inhalation of the 100mcg/50mcg OR 250mcg/50 OR 500mcg/50mcg DPI twice daily 
For children 4 to 11 years of age the usual dose is:
One inhalation of the 100 mcg/50 mcg DPI twice daily.

COPD:

The usual dose for adults (18 years and older) is:
One inhalation of the 250 mcg / 50 mcg OR the 500 mcg / 50 mcg DPI twice daily

PMS-Fluticasone Propionate/Salmeterol DPI contains two different drugs, salmeterol and fluticasone propionate that act in two different ways to help you breathe better. Salmeterol is a long-acting bronchodilator.  It relaxes the muscles in the walls of the small air passages in the lungs. This helps to open the airways and makes it easier for air to get in and out of the lungs. Fluticasone is a potent corticosteroid that possesses strong local anti-inflammatory activity. It reduces swelling and irritation in the walls of the small air passages in the lungs to ease breathing problems. Fluticasone also helps prevent asthma attacks.

Along with its needed effects, this medication may cause some unwanted or undesirable effects. The severity and duration of these effects are dependent on many factors including duration of therapy, dose, and individual response. Occasionally, some people feel a little shaky or have a headache or notice that their heart is beating faster than usual. These effects usually wear off with continued treatment. Tell your doctor about unwanted effects, but do not stop treatment unless told to do so.
Common:

• hoarseness
• throat irritation
• thrush of the mouth and throat

Less common:

• palpitations (awareness of heart beat)
• cough

Rare:

• irregular heart rhythms
• pain in joints
• muscle cramps

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.

If you are not responding to your usual dose, or your symptoms get worse, contact your doctor. Never increase the dose or frequency of the dose without being instructed to do so by your doctor.
Do not take any other respiratory medications without your doctor's approval.
Treatment should never be stopped without first consulting your doctor.
Discontinuation requires a gradual tapering of the dose and/or frequency or you may experience a flare-up of your condition.
The safety and efficacy in children under the age of 4 is not known.
People who have been treated with long term oral corticosteroids (e.g. prednisone) and are being switched to PMS-Fluticason propionate/Salmeterol DPI should start it before stopping the oral corticosteroid. The oral corticosteroid should then be gradually withdrawn.
The fluticasone in this medication may make people more susceptible to respiratory infections and may mask the symptoms of an existing infection. If you suspect that you may have a respiratory tract infection, contact your physician.
This immune system suppression also makes people more susceptible to getting thrush of the mouth and throat. Thrush is a fungal infection. To best prevent getting thrush, it is wise to rinse your mouth out with water after use.
Be sure to tell your doctor and pharmacist about any prescription or over-the-counter medications you are taking in order to avoid any potentially dangerous interactions.

The following drugs may interact with PMS-Fluticasone Propionate/Salmeterol DPI:

• short-acting beta-agonists (e.g.salbutamol)
• MAO (monoamine oxidase) inhibitors (e.g. phenelzine, tranylcypromine)
• tricyclic antidepressants (e.g. amitriptyline, imipramine)
• methylxanthines (e.g. theophylline)
• some beta-blockers (e.g. propranolol)
• ritonavir (e.g. Norvir®)

Use is not recommended in the following situations:

• allergy to any component 
• patients with allergic reactions to lactose or milk
• cardiac arrhythmia associated with tachycardia (irregular heartbeat associated with rapid heart rate)
• people with untreated fungal, bacterial or tuberculosis infections

Caution is recommended in the following situations:

• hypothyroidism
• diabetes
• cirrhosis
• glaucoma
• cardiovascular disorders
• cardiac arrhythmia (irregular heartbeat)

Use in pregnancy: Generally considered safe in pregnancy. Consult your doctor or pharmacist before use.
Use while breast-feeding: Generally considered safe if breast-feeding. Consult your doctor or pharmacist before use.

As with all long-acting beta 2-agonists and beta 2-agonist/corticosteroid combinations, PMS-Fluticasone Propionate/Salmeterol DPI carries a warning that long-acting beta 2-agonists have been associated with asthma death. These warnings are based on a U.S. study using salmeterol.