Increased plasma conc w/ fluoxetine. Slightly decreased exposure w/ nortriptyline. Increased effects of anti-hypertensives [eg, diuretics, β-blockers, ACE inhibitors, other Ca antagonists, α-adrenergic blocking agents (eg, α1
inhibitors, α-methyldopa]. Tab:
Reduced efficacy w/ rifampicin. Reduced bioavailability w/ CYP3A4-inducing anti-epileptic drugs (eg, phenobarb, phenytoin or carbamazepine). Potential increased plasma conc w/ macrolide antibiotics (eg, erythromycin); anti-HIV PIs (eg, ritonavir); azole anti-mycotics (eg, ketoconazole); nefazodone; quinupristin/dalfopristin; cimetidine; valproic acid; grapefruit juice. Infusion:
Mutual potentiation of negative ionotropic action w/ simultaneous IV administration of β-blockers. Renal function deterioration w/ aminoglycosides, cephalosporins, furosemide. Increased AUC of zidovudine IV.