Doubled effect of alcohol on psychomotor function, attention & memory. Possible increase in plasma conc w/ strong CYP2C19 inhibitors (eg, fluconazole, fluvoxamine). Decreased plasma conc w/ strong enzyme inducers (eg, rifampicin; carbamazepine, phenobarb, phenytoin; St. John's wort). May increase plasma conc of CYP2C19-metabolised products (eg, lansoprazole, omeprazole, diazepam); OAT3-transported medicinal products. May decrease plasma conc of CYP2B6-metabolised products (eg, efavirenz). Increased conc of carbamazepine epoxide.