Thrombocytopenia and Vancomycin

Even if cases of vancomycin-induced thrombocytopenia have been reported, it is not clear yet which is the mechanism at the basis of this association. Now, antibodies G and M have been studied in 29 patients with anamnesis suggesting vancomycin-induced thrombocytopenia (these antibodies were neither found in 25 patients to whom vancomycin was administered without the development of thrombocytopenia, nor in 10 patients with thrombocytopenia after quinine. Immunoglobulins M were found in only one blood donor out of obviously healthy 451 donors).
Patients with presence of antibodies had taken vancomycin for averagely 8 days, reaching a minimal value or 13.600 platelets/ml and taking 7 days to come back to basal values after vancomycin interruption. 5 patients presented thrombocytopenia immediately after the first dose of vancomycin; this event is probably due to the presence of antibodies previous to antibiotic administration. Ten out of the 29 patients with IgG and IgM presented severe (gastroenteric and urinary) bleedings during the period of thrombocytopenia, while there were neither brain haemorrhages nor deaths for haemorrhage.

Vancomycin-induced thrombocytopenia is typically very severe, even if clinical consequences described in the trial are not common and probably are due to the physical conditions of examined hospitalized patients. In any case, the use of this antibiotic must be strictly monitored from a haematological point of view.