Limbitrol and Renal/liver disease

Benzodiazepines are metabolized by the liver, and the metabolites are excreted in the urine. Chlordiazepoxide, clorazepate, diazepam, flurazepam and quazepam undergo oxidative N-dealkylation to active metabolites that are substantially longer-acting than the parent compound. These metabolites then undergo further biotransformation to pharmacologically inactive products before excretion by the kidney. Therapy with benzodiazepines should be administered cautiously at lower initial dosages in patients with impaired renal and/or hepatic function. Agents that are converted to weakly active, short-acting, or inactive metabolites may be preferable in hepatic impairment. Lorazepam, oxazepam and temazepam are conjugated to inactive metabolites, while alprazolam, estazolam and triazolam undergo hydroxylation to weakly active or inactive metabolites.

Tricyclic and tetracyclic antidepressants (TCAs) are known to undergo metabolism in the liver. Some of the metabolites, such as those of imipramine, clomipramine and desipramine, may be pharmacologically active. Many of the metabolites are also excreted by the kidney. There are very limited data concerning the use of TCAs in patients with renal and/or liver disease. Therapy with TCAs should be administered cautiously in patients with significantly impaired renal or hepatic function. Dosage adjustments may be necessary.