In vitro studies of the effect of flunitrazepam on cellular immune parameters

: We investigated in vitro the influence of flunitrazepam concentrations ranged between 10 and 140 ng/ml on immunological parameters by using the rosette-inhibition-test and the lymphocyte-transformation-test. After addition of 30 ng/ml flunitrazepam, which is in accordance with a threshold concentration of 1 mg flunitrazepam after intravenous injection, we saw a significant decrease of the positive cells in the rosette-inhibition-test. In higher concentrations no significant changes could be observed. By the lymphocyte-transformation-test no significant evidence of immunodepression could be demonstrated in concentration usually achieved during anaesthesia or possibly after long term application in intensive care unit, independent of the used mitogenes. Thus, flunitrazepam demonstrates no immunosuppressive effect in concentrations achieved during anaesthesia or in intensive care unit as could be observed by tests of cellular immune competence. However, one has to take into consideration that only parts of the immunesystem could be examined with these tests and in vivo-investigations have to verify these results.