butabarbital and olopatadine intranasal the two boost sedation. Avoid or Use Alternate Drug. Coadministration will increase danger of CNS despair, which can lead to additive impairment of psychomotor performance and cause daytime impairment.butabarbital will decrease the level or impact of fosphenytoin by influencing hepatic enzyme CYP2C9/10 metabo… Read More