Acid-base disturbances & additive effect w/ oral carbonic anhydrase inhibitors. Inhibited metabolism by CYP3A4 inhibitors eg, ketoconazole, itraconazole, clotrimazole, ritonavir, troleandomycin. Hypotension &/or marked bradycardia w/ oral Ca-channel blockers, β-blockers, antiarrythmics (eg, amiodarone), digitalis glycosides, parasympathomimetics or guanethidine. Decreased response to adrenaline. Potentiated hypertensive reaction to sudden clonidine w/drawal. Potentiated systemic β-blockade w/ CYP2D6 inhibitors eg, quinidine, fluoxetine, paroxetine. Increased hypoglycaemic effect of antidiabetic agents. Mydriasis w/ adrenaline.