Possible Interaction: Phenobarbital and Vitamin K

“In a search for easy toxicological management of chlorophacinone poisoning treated by phytomenadione and a cytochrome P450 inducer ( phenobarbital ), PI and chlorophacinone plasma levels were monitored concomitantly during 17 days.”

“ Menadione toxicity was increased when the rats were injected with sodium phenobarbital (PB) (4 x 80 mg/kg body wt.).”

“Supplements of 2.2 mg menadione and 1.0 g sodium phenobarbital kg-1 RSM diet induced slight reductions in the number of cases of liver haemorrhage or their severity, indicating that the multifunction oxidase system may be involved in rapeseed hepatotoxicity.”

“A similar reduction in the concentration of vitamin K1 in the blood of epileptic mothers treated with anticonvulsants such as phenobarbitone may explain the coagulation defect frequently observed in their offspring [K. R. Mountain, J. Hirsh and A.S. Gallus, Lancet ii, 265 (1970)].”

“ Phenobarbitone pretreatment significantly (P less than 0.01) increased the plasma clearance of vitamin K1 and decreased the terminal (beta) half-life from 2.08 +/- 0.56 to 0.99 +/- 0.30 hr.”