Benzodiazepines: a summary of pharmacokinetic properties.
1981; Wiley; Volume: 11; Issue: S1 Linguagem: Inglês
10.1111/j.1365-2125.1981.tb01833.x
ISSN1365-2125
AutoresD J Greenblatt, Richard I. Shader, Marcia Divoll, JS Harmatz,
Tópico(s)Analytical Chemistry and Chromatography
Resumo1 The onset and duration of action of benzodiazepines after single oral doses depend largely on absorption rate and extent of distribution, respectively. 2 The rate and extent of accumulation during multiple dosage depend on elimination half‐life and clearance. A framework is proposed for classification of benzodiazepines according to elimination half‐life. 3 Long‐acting benzodiazepines have half‐life values usually exceeding 24 hours. Drugs in this category have long‐acting pharmacologically active metabolites (often desmethyldiazepam), accumulate extensively during multiple dosage, and may have impaired clearance in the elderly and those with liver disease. 4 Intermediate and short‐acting benzodiazepines have half‐life values from 5‐24 hours. Active metabolites are uncommon. Accumulation during multiple dosage is less extensive than with the long‐acting group, and diminishes as the half‐life becomes shorter. Age and liver disease have a small influence on metabolic clearance. 5 The half‐life of ultrashort acting benzodiazepines is less than 5 hours. These drugs are essentially non‐ accumulating. 6 Pharmacokinetic classification may assist in understanding of differences among benzodiazepines, but does not explain all of their clinical actions.
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