Blunted ocular hypotensive response by TCAs. Additive or potentiated effect w/ CNS depressants eg, alcohol, barbiturates, opiates, sedatives, anaesth. Reduced pulse & BP w/ α-adrenergic agonists. Acid-base disturbances & additive systemic effects w/ oral carbonic anhydrase inhibitors. Inhibited metabolism w/ CYP3A4 inhibitors eg, ketoconazole, itraconazole, clotrimazole, ritonavir, troleandomycin. Medicinal products affecting metabolism & uptake of circulating amines eg, chlorpromazine, methylphenidate, reserpine, SNRIs. Concomitant use w/ antihypertensives &/or cardiac glycosides; isoprenaline, prazosin.