Increased budesonide systemic side effects w/ strong CYP3A inhibitors eg, itraconazole, ketoconazole, HIV PIs, cobicistat-containing products. Increased glycopyrronium total systemic exposure & decreased renal clearance w/ cimetidine. Potentiated adverse reactions w/ other anticholinergics &/or long-acting β
2-adrenergics. Potentially additive effects w/ other β
2-adrenergics. Potentiated hypokalaemia w/ xanthine derivatives, steroids, non-K-sparing diuretics. Weakened or inhibited formoterol effect w/ β-adrenergics. Prolonged QT interval & increased risk of ventricular arrhythmias w/ quinidine, disopyramide, procainamide, antihistamines, MAOIs, TCAs, phenothiazines. Impaired cardiac tolerance towards β
2-sympathomimetics w/ L-dopa, L-thyroxine, oxytocin, alcohol. Precipitated hypertensive reactions w/ MAOIs, furazolidone, procarbazine. Elevated risk of arrhythmias in concomitant anaesth w/ halogenated hydrocarbons.