DISCONTINUING PENICILLIN PROPHYLAXIS IN CHILDREN WITH SICKLE-CELL-ANEMIA

Objective: To evaluate the consequences of discontinuing penicillin pr ophylaxis at 5 years of age in children with sickle cell anemia who ha d received prophylactic penicillin for much of their lives. Design: Ra ndomized, double-blind, placebo-controlled trial. Setting Eighteen tea ching hospitals throughout the United States. Patients: Children with sickle cell anemia (hemoglobin SS or hemoglobin S beta(0)-thalassemia) who had received prophylactic penicillin therapy for at least 2 years immediately before their fifth birthday and had received the 23-valen t pneumococcal vaccine between 2 and 3 years of age and again at the t ime of randomization. Of 599 potential candidates, 400 were randomly s elected and followed for an average of 3.2 years. Interventions: After randomization, patients received the study medication twice daily-eit her penicillin V potassium, 250 mg, or an identical placebo tablet. Pa tients were either seen in the clinic or contacted every 3 months ther eafter for an interval history and dispensing of the study drug. A phy sical examination was scheduled every 6 months. Main outcome measures: The primary end point was a comparison of the incidence of bacteremia or meningitis caused by Streptococcus pneumoniae in children continui ng penicillin prophylaxis versus those receiving the placebo. Results: Six children had a systemic infection caused by 5. pneumoniae, four i n the placebo group (2.0%; 95% confidence interval 0.5%, 5.0%) and two in the continued penicillin prophylaxis group (1.0%; 95% confidence i nterval 0.1%, 3.6%), with a relative risk of 0.5 (95% confidence inter val 0.1, 2.7). All invasive isolates were either serotype 6(A or B) or serotype 23F. Four of the isolates were penicillin susceptible, and t wo (one from each treatment group) were penicillin and multiply antibi otic resistant. Adverse effects of the study drug were reported for th ree patients (nausea, vomiting, or both), one of whom was in the place bo group. Conclusion: Children with sickle cell anemia who have not ha d a prior severe pneumococcal infection or a splenectomy and are recei ving comprehensive care may safely stop prophylactic penicillin therap y at 5 years of age. Parents must be aggressively counseled to seek me dical attention for all febrile events in children with sickle cell an emia.