Alcohol, general anaesth & narcotic analgesics; INH & erythromycin, rifampicin, mirtazapine or TCAs; antiepileptics eg, carbamazepine, phenobarb & phenytoin, antihistamines, antihypertensives eg, ACE inhibitors, β-blockers or Ca-channel blockers or hydralazine, antipsychotics eg, clozapine & olanzapine; amprenavir, ritonavir & saquinavir; anxiolytics, digoxin, disulfiram, diuretics, dopaminergic agents, hypnotics, lofexidine, muscle relaxants, nabilone, nicotine, nitrates, OCs, sedatives, Na oxybate, cimetidine, xanthines.