We investigated whether a new non-benzodiazepine anti-anxiety drug, alpidem, produces weaker withdrawal symptoms than alprazolam.
Under a double-blind procedure, 122 patients suffering from general anxiety disorders were randomly allocated to either alpidem (50 mg, three times a day) or alprazolam (0.5 mg, three times a day) for six weeks, followed by a two-week placebo withdrawal phase. The diagnosis of withdrawal syndrome (WS) was made, in blind conditions, on the basis of the Withdrawal Symptom Check List (WSCL), after one or two weeks of discontinuation of active treatment.
The WS occurred significantly less frequently in the alpidem group (n = 10, 18%) than in the alprazolam group (n = 26, 48%). Typical withdrawal symptoms on the WSCL were also significantly less severe (P = 0.044) in the alpidem group compared with the alprazolam group.
Alpidem may be a valid alternative to current benzodiazepine anxiolytic therapy because it produces fewer and weaker withdrawal symptoms than alprazolam and is better tolerated.