Effects of acute and chronic Triazolam treatments on brain GABA levels in albino rats

The present study investigated the effects of acute and chronic intraperito neal administration of Triazolam on g-aminobutyric acid (GABA) levels in di fferent brain areas of albino rats. Three experiments were conducted. In th e first, five groups of rats were acutely treated with different doses of T riazolam (0.25 mg/kg-4.0 mg/kg). In the second experiment, rats were treate d chronically with a single daily dose of Triazolam (started with 0.25 mg/k g and increased by time to 1.0 mg/kg) for 5 weeks, simulating clinical use. In the third, rats were treated chronically with three daily doses of Tria zolam (started with 0.25 mg/kg and increased by time to 0.5 mg/kg) for 20 d ays, representing a form of drug abuse. Brain levels of GABA and plasma lev els of Triazolam were measured using high performance liquid chromatography (HPLC). The acute Triazolam administration produced an increase in GABA le vels in all brain areas studied. The chronic administration of single daily dose of Triazolam produced normal GABA levels in all brain areas except br ain stem where the levels were significantly decreased; this indicates the development of tolerance to Triazolam action on increasing GABA content. Th e chronic administration of three daily doses of Triazolam produced a decre ase in GABA levels in ail brain regions studied. In conclusion, chronic sin gle daily dose treatment (representing normal use) produces tolerance to Tr iazolam effects on brain GABA levels, while chronic three daily doses admin istration (akin to drug abuse) causes a fall in GABA levels.