Benzodiazepines, but not antidepressants or neuroleptics, induce dose-dependent development of tolerance to lorazepam in psychiatric patients.
Psychomotor effects of oral lorazepam 3 mg were studied in psychiatric patients stratified into four groups: 1) a group of six patients with no previous use of psychotrophic drugs (NoD), 2) a group of 12 patients treated with antidepressants and/or neuroleptics (PsyD), 3) a group of 10 patients treated with low doses of benzodiazepines (BZs) (lowBZ), and 4) a group of nine patients treated with high doses of BZs (high BZ). Similar objective psychomotor tests and subjective assessments were administered under single-blind conditions to all treatment groups at baseline, after intake of placebo, and after intake of 3 mg lorazepam. Both lorazepam (CGC) and total BZs (bioassay) in serum were assayed. The results demonstrate that treatment with BZs induce dose-dependent development of tolerance to psychomotor effects of lorazepam. Antidepressants and neuroleptics failed to induce cross-tolerance to lorazepam. The rise in serum lorazepam concentrations after lorazepam intake was similar (about 28 micrograms/l) in all treatment groups, suggesting a functional, not dispositional, tolerance. However, the initial learning effect in psychomotor performance was poorer among BZ users than among others.
Aranko
K
K
Mattila
M J
MJ
Nuutila
A
A
Pellinen
J
J
D000284:Administration, Oral; D014151:Anti-Anxiety Agents / Q000097:blood / Q000494:pharmacology*; D000928:Antidepressive Agents / Q000494:pharmacology; D014150:Antipsychotic Agents / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004361:Drug Tolerance; D006801:Humans; D008140:Lorazepam / Q000008:administration & dosage / Q000494:pharmacology*; D001523:Mental Disorders / Q000188:drug therapy* / Q000503:physiopathology / Q000523:psychology; D011597:Psychomotor Performance / Q000187:drug effects
D014151:Anti-Anxiety Agents; D000928:Antidepressive Agents; D014150:Antipsychotic Agents; D008140:Lorazepam