This system is probably from the induction of hepatic microsomal enzymes that metabolize the antibiotic. If phenobarbital and doxycycline are administered concurrently, the clinical response to doxycycline ought to be monitored intently. Phenytoin, sodium valproate, valproic acid: The result of barbiturates within the metabolism of phenytoin appears to get variable. https://elizabeths479zzb3.wikigdia.com/user