RESUMO
OBJECTIVE: Monocytes play an important part in all phases of both humoral and cell-mediated immune responses. In our study, we examined the influence of various drugs used in intensive care (omeprazole, ranitidine, potassium canrenoate, furosemide, clonidine, verapamil, and metamizole) on monocyte chemotaxis in vitro. The 0,1 fold, 1 fold, and 10 fold concentrations, which are detectable in serum after a clinically efficacious bolus injection of the respective drug, were tested. METHODS: Using centrifugation, mononuclear cells were isolated from venous blood samples obtained from 10 healthy volunteers. Monocyte chemotaxis was determined by means of a microchemotaxis chamber. N-formyl-methionylleucylphenylalanine served as chemoattractant. RESULTS: Omeprazole, ranitidine, and potassium canrenoate did not influence monocyte chemotaxis. While the 10 fold concentrations of the clinically efficacious serum concentrations of furosemide and verapamil caused a significant inhibition, the 10 fold concentrations of the clinically efficacious serum concentrations of clonidine and metamizole significantly stimulated monocyte motility. CONCLUSION: Clinically relevant concentrations of the drugs tested did not alter monocyte chemotaxis in vitro. However, 10 fold concentrations of the clinically efficacious serum concentrations, which might occur in vivo due to drug interaction, cumulation, altered elimination, or accidental overdose, caused an inhibition (furosemide, verapamil) or a stimulation (clonidine, metamizole). An in vitro investigation does never permit to jump to clinical conclusions. However, our study gives impulses to conduct intensive care examinations concerning the influence of drugs on monocyte functions particularly since these cells are of great prognostical importance regarding sepsis.