Didanosine-associated eosinophilia with acute thrombocytopenia

OBJECTIVE: To report a case of didanosine (ddI)-induced acute thrombocytopenia and to discuss the incidence of this occurrence. CASE SUMMARY: A 42-year-old man was admitted to the hospital on November 21, 1991, with acute thrombocytopenia. The patient had an AIDS index diagnosis of Kaposi's sarcoma (KS) in 1988 and had been taking zidovudine (ZDV) for three years without any adverse effects. On July 26, 1991, he complained of increasing fatigue and weight loss. At that time, the therapy was changed from ZDV to ddI. Over the next four months the drug therapy was altered from ddI to ZDV and ZDV to ddI because of increasing fatigue and gastrointestinal symptomatology; all of the other chronic medications were maintained at the same dosages and frequency. All laboratory work remained stable and no new active processes were found during this period. The patient developed acute thrombocytopenia upon his last change to ddI and all of the chronic drug therapy was stopped. His platelet count returned to his baseline value three weeks after the discontinuation of ddI and reinstitution of his chronic medications. DISCUSSION: A review of the literature showed two documented cases of thrombocytopenia with ddI on a dosage escalation study. CONCLUSIONS: Close patient monitoring is essential while administering ddI.