Patients should consult their physicians before taking any additional prescriptions, over-the-counter medications, nutritional supplements or herbal medications. Of particular concern to individuals taking asthma medications are:

• Drugs that suppress the immune system (e.g., cyclosporine). Can interfere with the function of oral and intravenous corticosteroids.
  
  
• High-doses of aspirin or anticoagulants (medications that inhibit the blood’s ability to clot) can increase the risk of stomach bleeding or ulcers when used with oral corticosteroids. However, aspirin should not be used by anyone with asthma, unless they have a physician's approval, because the drug can trigger an asthma attack in some asthmatic individuals.
  
  
• Diabetic medications (e.g., insulin). Can interfere with the function of oral and intravenous corticosteroids, requiring changes in dosage.
  
  
• Large amounts of caffeine. Can increase the side effects of theophylline.
  
  
• Seizure medications. Phenytoin can decrease the effectiveness of oral and intravenous corticosteroids and decrease blood levels of theophylline. Carbamazepine can decrease theophylline blood levels.
  
  
• Phenobarbital (a sedative). Can decrease the effectiveness of oral and intravenous corticosteroids.
  
  
• Rifampin (used to treat tuberculosis). Can decrease the effectiveness of oral and intravenous corticosteroids.
  
  
• Ketoconazole (used to treat fungal infections). Can lead to a build up of oral and intravenous corticosteroids in the blood, increasing toxicity.
  
  
• Erythromycin and ciprofloxacin (antibiotics). Erythromycin can increase the blood levels and toxicity of oral and intravenous corticosteroids. Erythromycin and ciprofloxacin can lead to a build up of theophylline in the blood, increasing toxicity.
  
  
• Cimetidine (used to treat ulcers). Can lead to a build up of theophylline in the blood, increasing toxicity.

There are no known drug or food interactions with the following asthma medications:

• Inhaled corticosteroids
• Leukotriene modifiers
• Beta2 agonists
• Inhaled anticholinergics
• Mast cell stabilizers