[The immune system and benzodiazepines]

Alterations of the immune-system by benzodiazepines are of minor degree in dependence of their central or peripheral activity. Regarding their central effects a modulation may be assumed via the endocrine system. In vitro and in vivo studies lead to the assumption, that benzodiazepines have a mutagenic effect, even though this hypothesis could not be confirmed by in vitro investigations. In vivo a possible mutagenic action could only be found in two patients after long term therapy. A more mitosis-inhibiting effect of diazepam was shown in in vitro studies. In animal experiments this observation could not be confirmed for the thymus. With regard to specific immunity, diazepam seems to have a stimulating effect on the T-helper cells. Locomotion and chemotaxis of human polymorphonuclear granulocytes is not influenced by anaesthetic doses of benzodiazepines. It is questionable whether benzodiazepines are of clinical importance for the immune-system of patients receiving anaesthetic doses. However, the presently generous use of benzodiazepines, e.g. on intensive care units, should be reconsidered in respect to immunological consequences.