Paradoxical elevations in IOP w/ other prostagladin analogues. Potentiated effect on IOP w/ oral β-adrenergic blocking agent. Hypotension or marked bradycardia w/ oral Ca channel blockers, β-adrenergic blocking agents, antiarrhythmics, digitalis glycosides, parasympathomimetics, guanethidine. Mydriasis w/ epinephrine. Potentiated hypertensive reaction to sudden w/drawal of clonidine. May increase hypoglycemic effect of antidiabetics. Potentiated systemic β-blockade eg, decreased heart rate, depression w/ CYP2D6 inhibitors.