Fluticasoneinteractions

Fluticasone propionate and salmeterol HFA has been used concomitantly with other drugs, including short-acting beta 2 -agonists, methylxanthines, and nasal corticosteroids, commonly used in patients with asthma without adverse drug reactions. No formal drug interaction trials have been performed with fluticasone propionate and salmeterol HFA.

Strong cytochrome P450 3A4 inhibitors (e.g., ritonavir, ketoconazole): Use not recommended. May increase risk of systemic corticosteroid and cardiovascular effects.

Monoamine oxidase inhibitors and tricyclic antidepressants: Use with extreme caution. May potentiate effect of salmeterol 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 P450 3A4 Fluticasone propionate and salmeterol, the individual components of Fluticasone Propionate and Salmeterol HFA, are substrates of CYP3A4. The use of strong CYP3A4 inhibitors (e.g., ritonavir, atazanavir, clarithromycin, indinavir, itraconazole, nefazodone, nelfinavir, saquinavir, ketoconazole, telithromycin) with Fluticasone Propionate and Salmeterol HFA is not recommended because increased systemic corticosteroid and increased cardiovascular adverse effects may occur.

Ritonavir Fluticasone Propionate: A drug interaction trial with fluticasone propionate aqueous nasal spray in healthy subjects has shown that ritonavir (a strong CYP3A4 inhibitor) can significantly increase plasma fluticasone propionate exposure, resulting in significantly reduced serum cortisol concentrations. During postmarketing use, there have been reports of clinically significant drug interactions in patients receiving fluticasone propionate and ritonavir, resulting in systemic corticosteroid effects including Cushing’s syndrome and adrenal suppression.

Ketoconazole Fluticasone Propionate: Coadministration of orally inhaled fluticasone propionate (1,000 mcg) and ketoconazole (200 mg once daily) resulted in a 1.9-fold increase in plasma fluticasone propionate exposure and a 45% decrease in plasma cortisol area under the curve (AUC), but had no effect on urinary excretion of cortisol.

Salmeterol: In a drug interaction trial in 20 healthy subjects, coadministration of inhaled salmeterol (50 mcg twice daily) and oral ketoconazole (400 mg once daily) for 7 days resulted in greater systemic exposure to salmeterol (AUC increased 16-fold and C max increased 1.4-fold). Three subjects were withdrawn due to beta 2 -agonist side effects (2 with prolonged QTc and 1 with palpitations and sinus tachycardia). Although there was no statistical effect on the mean QTc, coadministration of salmeterol and ketoconazole was associated with more frequent increases in QTc duration compared with salmeterol and placebo administration.

7.2 Monoamine

Oxidase Inhibitors and Tricyclic Antidepressants Fluticasone Propionate and Salmeterol HFA should be administered with extreme 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 salmeterol, a component of Fluticasone Propionate and Salmeterol HFA, on the vascular system may be potentiated by these agents.

7.3 Beta-adrenergic

Receptor Blocking Agents Beta-blockers not only block the pulmonary effect of beta-agonists, such as salmeterol, a component of Fluticasone Propionate and Salmeterol HFA, but may also 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 for these patients; cardioselective beta-blockers could be considered, although they should be administered with caution.

7.4 Non–Potassium-Sparing

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, such as salmeterol, a component of Fluticasone Propionate and Salmeterol HFA, 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 Fluticasone Propionate and Salmeterol HFA with non–potassium-sparing diuretics.