Butabarbital will lower the level or impact of sulfamethoxazole by impacting hepatic enzyme CYP2C9/ten metabolism. Small/Significance Unknown. butabarbital will decrease the extent or influence of fosphenytoin by influencing hepatic enzyme CYP2C9/ten metabolism. Use Caution/Watch. Butabarbital belongs to the group of medicines termed barbiturates. They act in the central nervous process https://elizabethr012zwu9.wikicommunications.com/user