COADMINISTRATION OF VILANTEROL WITH KETOCONAZOLE AND OTHER KNOWN STRONG CYP3A4 INHIBITORS (E.G., RITONAVIR, CLARITHROMYCIN, CONIVAPTAN, INDINAVIR, ITRACONAZOLE, LOPINAVIR, NEFAZODONE, NELFINAVIR, SAQUINAVIR, TELITHROMYCIN, TROLEANDOMYCIN, VORICONAZOLE) MAY INCREASE ITS PLASMA CONCENTRATION & CHANCES OF SIDE EFFECTS.
VILANTEROL, LIKE OTHER BETA2-AGONISTS, SHOULD BE ADMINISTERED WITH EXTREME CAUTION TO PATIENTS BEING TREATED WITH MONOAMINE OXIDASE INHIBITORS, TRICYCLIC ANTIDEPRESSANTS, OR DRUGS KNOWN TO PROLONG THE QTC INTERVAL OR WITHIN 2 WEEKS OF DISCONTINUATION OF SUCH AGENTS, BECAUSE THE EFFECT OF ADRENERGIC AGONISTS ON THE CARDIOVASCULAR SYSTEM MAY BE POTENTIATED BY THESE AGENTS. DRUGS THAT ARE KNOWN TO PROLONG THE QTC INTERVAL HAVE AN INCREASED RISK OF VENTRICULAR ARRHYTHMIAS.
BETA-BLOCKERS NOT ONLY BLOCK THE PULMONARY EFFECT OF BETA-AGONISTS, BUT MAY PRODUCE SEVERE BRONCHOSPASM IN PATIENTS WITH REVERSIBLE OBSTRUCTIVE AIRWAYS DISEASE.
CO-ADMINISTRATION WITH NON-POTASSIUM-SPARING DIURETICS (SUCH AS LOOP OR THIAZIDE DIURETICS) CAN CAUSE INCREASED CHANCES OF HYPOKALEMIA, ESPECIALLY WHEN THE RECOMMENDED DOSE OF THE BETA-AGONIST IS EXCEEDED.