Symbicort Drug Interactions

Turbuhaler: Pharmacokinetic interactions: The metabolic conversion of budesonide is impeded by substances metabolized by CYP450 3A4 (e.g. itraconazole, ritonavir). The concomitant administration of these potent inhibitors of CYP450 3A4 may increase plasma levels of budesonide. The concomitant use of these drugs should be avoided unless the benefit outweighs the increased risk of systemic side effects.
Pharmacodynamic interactions: Beta-adrenergic blockers can weaken or inhibit the effect of formoterol. SYMBICORT should therefore not be given together with beta-adrenergic blockers (including eye drops) unless there are compelling reasons.
Concomitant treatment with quinidine, disopyramide, procainamide, phenothiazines, antihistamines (terfenadine), monoamine oxidase inhibitors (MAOIs) and tricyclic antidepressants can prolong the QTc interval and increase the risk of ventricular arrhythmias.
In addition, L-dopa, L-thyroxine, oxytocin and alcohol can impair cardiac tolerance towards beta₂-sympathomimetics.
Concomitant treatment with monoamine oxidase inhibitors including agents with similar properties such as furazolidone and procarbazine, may precipitate hypertensive reactions.
There is an elevated risk of arrhythmias in patients receiving concomitant anesthesia with halogenated hydrocarbons.
Concomitant use of other β-adrenergic drugs can have a potentially additive effect.
Hypokalemia may increase the disposition towards arrhythmias in patients who are treated with digitalis glycosides.
Budesonide; and formoterol (Turbuhaler 80/4.5 mcg/dose) has not been observed to interact with any other drugs used in the treatment of asthma.
Rapihaler: Pharmacokinetic interactions: The metabolism of budesonide is primarily mediated by the enzyme CYP3A4. Inhibitors of this enzyme, eg ketoconazole, may therefore increase systemic exposure to budesonide. This is of limited clinical importance for short-term (1 to 2 weeks) treatment with ketoconazole, but should be taken into consideration during long-term treatment with ketoconazole or other potent CYP 3A4 inhibitors.
Pharmacodynamic interactions: Neither budesonide nor eformoterol have been observed to interact with any other drug used in the treatment of asthma; or COPD (Rapihaler 160/4.5 mcg/dose).
β-receptor blocking agents: β-receptor blocking agents, especially those that are non-selective, may partially or totally inhibit the effect of β₂-agonists. These drugs may also increase airway resistance, therefore the use of these drugs in asthma patients is not recommended.
Other sympathomimetic agents: Other β-adrenergic stimulants or sympathomimetic amines such as ephedrine should not be given concomitantly with eformoterol, since the effects will be cumulative. Patients who have already received large doses of sympathomimetic amines should not be given eformoterol.
Xanthine derivatives, mineralocorticosteroids, and diuretics: Hypokalaemia may result from β₂-agonist therapy and may be potentiated by concomitant treatment with xanthine derivatives, mineralocorticosteroids, and diuretics (see Hypokalaemia under PRECAUTIONS).
Monoamine oxidase inhibitors, tricyclic antidepressants, quinidine, disopyramide, procainamide, phenothiazines and antihistamines: The adverse cardiovascular effects of eformoterol may be exacerbated by concurrent administration of drugs associated with QT-interval prolongation and increased risk of ventricular arrhythmia. For this reason caution is advised when eformoterol is administered to patients already taking monoamine oxidase inhibitors, tricyclic antidepressants, quinidine, disopyramide, procainamide, phenothiazines, or antihistamines associated with QT-interval prolongation (eg terfenadine, astemizole).