Symbicort Drug Interactions

Symbicort may negatively interact with prescription or over-the-counter medications that you are taking to treat other conditions.

Always talk to your doctor about the medications that you are taking before starting a Symbicort regimen. The following medications and types of drugs have been found to cause unwanted interactions with Symbicort:

• Theo-Dur (theophylline)
• Tagamet (cimetidine)
• Premarin (estrogen)
• Lanoxin (digoxin)
• Nizoral (ketoconazole)
• Donnatal (phenobarbital)
• Dilantin (phenytoin)
• Rifadin (rifampin)
• Aspirin
• Oral contraceptives
• Oral corticosteroids like Prednisone

Symbicort is contraindicated if you are taking one or more of the fallowing medications: Amiodarone, arsenic trioxide, astemizole, bepridil, cisapride, disopyramide, ibutilide, indapamide, pentamidine. When one or more of these medications are being used together with formoterol, QTc interval increases, causing a distinctive form of ventricular tachycardia called torsade de pointes.

Symbicort is also contraindicated if you are taking mifepristone. Mifepristone is contraindicated in patients on long term corticosteroid treatment. The mechanism of interactions is not known.  Symbicort should be used with caution when it used with CYP450 3A4 inhibitors, tricyclic antidepressants, beta-blockers and diuretics.

WARNINGS

• Long-acting beta₂ agonist like formoterol may increase the risk of asthma related deaths, for that reason this medicine should only be used as supplementary therapy for patients not effectively controlled on other controller medication such as inhaled corticosteroids. Formoterol can also be used for patients whose disease severity warrants initiation of treatment with 2 maintenance treatments.
• Symbicort should not be used without a concomitant long-term asthma control medication like an inhaled corticosteroid.
• Once asthma control is achieved and maintain, discontinuation of long-acting beta₂ agonist is recommended. It is advisable to maintain the patient on a long-term asthma control.
• When asthma is not adequately controlled, do not use Symbicort.
• For paediatric and adolescent patients it is recommended to use a fixed-dose combination product containing an inhaled corticosteroid and a long-acting beta2 agonist. This is to ensure adherence with both drugs.

Cautions

• Symbicort should be used with caution in patients with cardiovascular problems, convulsive attacks and/or thyrotoxicosis.
• When transferring patients from systemic corticosteroids to inhaled corticosteroids, particular care is needed, because of the risk of fatal adrenal insufficiency.
• Patients taking this medication are in risk of transient hypokalemia.