Background: Lung transplant (LT) recipients often receive dapsone for Pneumocystis jirovecii pneumonia (PCP) prophylaxis. However, the prevalence of dapsone-induced hematologic toxicity in LT recipients is unknown. We report a high prevalence of hemolytic anemia (HA) associated with dapsone use in LT patients when compared with other patients described in the literature who have been prescribed dapsone prophylaxis.
Methods: We performed a retrospective chart review on all LT recipients who received dapsone prophylaxis between 2004 and 2006. Demographics, ideal body weight (IBW), severity of anemia, transfusion requirements, laboratory evidence of hemolysis, serum creatinine and glucose-6-phosphate deyhdrogenase (G6PD) enzyme levels were collected.
Results: Forty-three patients received dapsone. Ten (22.7%) patients had HA, despite normal G6PD levels. The mean drop in hemoglobin from baseline was 2.7 g/dl (95% confidence interval [CI] 1.9 to 3.5, p < 0.0001). Of those patients with HA, 6 had elevated serum creatinine from baseline. The odds ratio for hemolysis was 4.75 for each 1.0-mg/dl increase in creatinine (95% CI 1.07 to 21.03, p = 0.04). Mean IBW for the HA group was 58.4 kg. A dapsone dose of 100 mg/day orally resulted in a mean dose of 1.7 mg/kg.
Conclusions: The prevalence of dapsone-induced HA in LT recipients is 5-fold higher than the reported rate in the population of human immunodeficiency virus (HIV) patients. Individuals with renal failure or low body weight and for whom dose exceeds 1.5 mg/kg may be at increased risk for dapsone-induced HA. Although current CDC guidelines do not recommend adjusting dose by IBW or renal function, we suggest that consideration should be given to these dosing strategies.