A pilot study of penicillin prophylaxis for neuropsychiatric exacerbationstriggered by streptococcal infections

Background: Some children with obsessive-compulsive disorder (OCD) and tic disorders appear to have symptom exacerbations triggered by group A beta-he molytic streptococcal infections in a manner that is similar to rheumatic f ever and its neurologic variant Sydenham's chorea. Because;penicillin proph ylaxis has proven to be effective in preventing recurrences of rheumatic fe ver, it was postulated that it might also prevent srreptococcal-triggered n europsychiatric symptom exacerbations in children with Pediatric Autoimmune Neuropsychiatric Disorders Associated with Streptococcal infections (PANDA S). These children are identified by five clinical characteristics: presenc e of OCD or tic disorder, prepubertal onset, episodic symptom course, neuro logic abnormalities (i.e., choreiform movements) and srreptococcal-triggere d symptom exacerbations. Methods: Thirty-seven children with PANDAS were enrolled in an 8 month, dou ble-blind, balanced cross-over study. Patients were randomized to receive e ither 4 months of the active compound (twice daily oral 250 mg penicillin V ) followed by 4 months of placebo, or placebo followed by penicillin V, Tie , OCD, and other psychiatric symptoms were monitored monthly. Throat cultur es and streptococcal antibody titers were also obtained. Results: There were an equal number of infections in both the active and pl acebo phases of the study. There was no significant change seen in either t he obsessive-compulsive or tic symptom severity between the two phases. Conclusions: Because of the failure to achieve an acceptable level of strep tococcal prophylaxis, no conclusions can be drawn from this study regarding the efficacy of penicillin prophylaxis in preventing tic or OCD symptom ex acerbations. Future studies should employ a more effective prophylactic age nt, and include a larger sample size.