Effects of chronic alprazolam treatment on plasma concentrations of glucocorticoids, thyroid hormones, and testosterone in cardiomyopathic hamsters.

In the first of two experiments, young male cardiomyopathic hamsters were injected intraperitoneally twice a day for 29 days with 8 mg alprazolam/kg body weight or saline. Three hours after the same injections on day 30, they were sacrificed and plasma hormone levels were measured. Alprazolam increased cortisol, total glucocorticoid and triiodothyronine levels. It did not affect corticosterone, thyroxine or testosterone levels. The same protocol was used in a second experiment, except the controls received vehicle and a third group was treated with 48 mg diazepam/kg body weight. Alprazolam again increased cortisol and total glucocorticoid levels, but not those of corticosterone. On the other hand, diazepam increased both cortisol and corticosterone levels. These experiments suggest that chronic benzodiazepine treatment can affect adrenocortical function and perhaps some aspects of thyroid function.