Budesonideinteractions

In clinical studies, concurrent administration of budesonide and formoterol fumarate dihydrate and other drugs, such as short-acting beta 2 -agonists, intranasal corticosteroids, and antihistamines/decongestants has not resulted in an increased frequency of adverse reactions. No formal drug interaction studies have been performed with budesonide and formoterol fumarate dihydrate.

Strong cytochrome P450 3A4 inhibitors (e.g., ritonavir): Use with caution. May cause increased systemic corticosteroid effects.

Monoamine oxidase inhibitors and tricyclic antidepressants: Use with extreme caution. May potentiate effect of formoterol on vascular system.

Beta-blockers: Use with caution. May block bronchodilatory effects of beta-agonists and produce severe bronchospasm.

Diuretics: Use with caution. Electrocardiographic changes and/or hypokalemia associated with non-potassium-sparing diuretics may worsen with concomitant beta-agonists.

7.1 Inhibitors of

Cytochrome P4503A4 The main route of metabolism of corticosteroids, including budesonide, a component of budesonide and formoterol fumarate dihydrate, is via cytochrome P450 (CYP) isoenzyme 3A4 (CYP3A4). After oral administration of ketoconazole, a strong inhibitor of CYP3A4, the mean plasma concentration of orally administered budesonide increased. Concomitant administration of CYP3A4 may inhibit the metabolism of, and increase the systemic exposure to, budesonide. Caution should be exercised when considering the coadministration of budesonide and formoterol fumarate dihydrate with long-term ketoconazole and other known strong CYP3A4 inhibitors (e.g., ritonavir, atazanavir, clarithromycin, indinavir, itraconazole, nefazodone, nelfinavir, saquinavir, telithromycin).

7.2 Monoamine

Oxidase Inhibitors and Tricyclic Antidepressants Budesonide and formoterol fumarate dihydrate should be administered with caution to patients being treated with monoamine oxidase inhibitors or tricyclic antidepressants, or within 2 weeks of discontinuation of such agents, because the action of formoterol, a component of budesonide and formoterol fumarate dihydrate, on the vascular system may be potentiated by these agents. In clinical trials with budesonide and formoterol fumarate dihydrate, a limited number of COPD and asthma patients received tricyclic antidepressants, and, therefore, no clinically meaningful conclusions on adverse events can be made.

7.3 Beta-Adrenergic

Receptor Blocking Agents Beta-blockers (including eye drops) may not only block the pulmonary effect of beta-agonists, such as formoterol, a component of budesonide and formoterol fumarate dihydrate, but may produce severe bronchospasm in patients with asthma. Therefore, patients with asthma should not normally be treated with beta-blockers. However, under certain circumstances, there may be no acceptable alternatives to the use of beta-adrenergic blocking agents in patients with asthma. In this setting, cardioselective beta-blockers could be considered, although they should be administered with caution.

7.4 Diuretics

The ECG changes and/or hypokalemia that may result from the administration of non-potassium-sparing diuretics (such as loop or thiazide diuretics) can be acutely worsened by beta-agonists, especially when the recommended dose of the beta-agonist is exceeded. Although the clinical significance of these effects is not known, caution is advised in the coadministration of budesonide and formoterol fumarate dihydrate with non-potassium-sparing diuretics.