The present study investigated the effects of acute and chronic intraperitoneal administration of
Triazolam on g-
aminobutyric acid (
GABA) levels in different brain areas of albino rats. Three experiments were conducted. In the first, five groups of rats were acutely treated with different doses of
Triazolam (0.25 mg/kg-4.0 mg/kg). In the second experiment, rats were treated chronically with a single daily dose of
Triazolam (started with 0.25 mg/kg 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
Triazolam (started with 0.25 mg/kg and increased by time to 0.5 mg/kg) for 20 days, representing a form of
drug abuse. Brain levels of
GABA and plasma levels of
Triazolam were measured using high performance liquid chromatography (HPLC). The acute
Triazolam administration produced an increase in
GABA levels in all brain areas studied. The chronic administration of single daily dose of
Triazolam produced normal
GABA levels in all brain areas except brain stem where the levels were significantly decreased; this indicates the development of tolerance to
Triazolam action on increasing
GABA content. The chronic administration of three daily doses of
Triazolam produced a decrease in
GABA levels in all brain regions studied. In conclusion, chronic single daily dose treatment (representing normal use) produces tolerance to
Triazolam effects on brain
GABA levels, while chronic three daily doses administration (akin to
drug abuse) causes a fall in
GABA levels.