Phenobarbital Digoxin

Drug Interactions Other antihypertensive agents Carbamazepine (vasodilators, ACE inhibitors, Rifampin diuretics, and beta-blockers) Phenobarbital Digoxin Cyclosporine Disopyramide Theophylline Flecainide Inhalation anesthetics Quinidine Neuromuscular blocking agents Cimetidine Lithium ... 

P-gp (ABCB1) Verapamil, digoxin, mitoxantrone, vinblastine, doxorubicin, losartan, talinolol, cortisol, dexamethasone, colchicine, loperamide, domperidone, indinavir, erythromycin, tetracycline, itraconazole, cyclosporine, methotrexate, amitryptyline, phenobarbital, morphine, cimetidine, and others... 

Age-related variations in central nervous system (CNS) neurotransmitter production and receptor sensitivity are the most likely explanations for the pharmacodynamic differences observed between children and adults following administration of psychotropic medications [39a], Children have lower phenobarbital ratios than adults, and the ratio increases with gestational age [40,41]. Conversely, a lower therapeutic range for children has been identified for cyclosporine, phenytoin, and digoxin [42]. 

Substances which enter the enterohepatic circulation Carbamazepine, digoxin, phenobarbital. 

Multiple drug interactions have been discribed (decreased serum concentrations of phenobarbital, phenytoin, sulfinpyrazone and rifampin, increased serum concentrations of quinidine, carbamazepine, cyclosporin). Important in this setting is that a marked interaction exists between digoxin and verapamil, increasing the serum concentrations of the former due to decreased renal excretion,... 

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