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.