This mechanism is probably from the induction of hepatic microsomal enzymes that metabolize the antibiotic. If phenobarbital and doxycycline are administered concurrently, the medical response to doxycycline need to be monitored closely. Phenytoin, sodium valproate, valproic acid: The result of barbiturates on the metabolism of phenytoin seems to be variable. https://johnathanwmzkv.blogaritma.com/28439167/indicators-on-lsds-you-should-know