THROMBOCYTOPENIA INDUCED BY NONCYTOTOXIC DRUGS IN DENMARK 1968-91

Objectives. To analyse the distribution of noncytotoxic drugs reported as cause of thrombocytopenia during a 24-year period, and to draw att ention to the most commonly involved drugs in modern clinical practice . Design/setting. Retrospective study of spontaneous case reports from the Danish reporting system on adverse drug reactions. Subjects. A to tal of 309 critically reviewed cases of drug-induced thrombocytopenia reported during the period from 1968 to the end of 1991. Results. Sodi umaurothiomalate and the combination sulfamethoxazole with trimethopri m were the most commonly reported single drugs, and nonsteroid anti-in flammatory drugs were the most frequently reported category of drugs. A pronounced shift in the spectrum of causal drugs was observed due to the introduction of new drugs and alterations in drug consumption. At present, valproic acid and measles-mumps-rubella vaccine are most num erously reported. The still-growing list of thrombocytopenia-inducing agents contained 110 different drugs. At present, 20% of reported case s concern drugs not previously registered as causing thrombocytopenia in Denmark. Twenty-five per cent of all cases were caused by drugs whi ch appeared only sporadically in the material. Conclusions. The spectr um of drugs reported as causing drug-induced thrombocytopenia is broad ening and changing progressively, reflecting changes in drug consumpti on. The most frequently reported drugs at present are valproic acid an d measles-mumps-rubella vaccine.