Evaluation of anxiolytic effect and withdrawal anxiety in chronic intermittent diazepam treatment in rats

This study evaluated the effect of intermittent administration in the development of dependence to diazepam in chronic use of the drug. Gabapentin was used to provide an anxiolytic effect on drug-free days. During a 28-day treatment schedule, rats were given diazepam (15 mg/kg) once daily continuously, or intermittently with saline or gabapentin (50 mg/kg) on days 5, 10, 15, 20, and 25. Anxiety-like behavior was assessed on days 10 and 30 using the elevated plus-maze test and novelty-induced grooming test. Contrary to continuous administration, intermittent diazepam did not provide anxiolytic-like activity on day 10; instead, it prevented withdrawal anxiety on day 30. Gabapentin produced anxiolytic-like effects during the withdrawal period, but not on day 10. These results suggest that intermittent administration of diazepam (given either alone or alternatively with a drug possessing anxiolytic activity) may be of value in preventing the development of physical dependence during the chronic use of the drug. However, further studies are needed to demonstrate that this protocol could effectively produce anxiolytic activity on diazepam-free days. Behavioural Pharmacology 23:215-219 (C) 2012 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.