Determination of serum penicillin levels using high performance liquid chromatography (HPLC) and disk diffusion method among Filipino rheumatic patients following benzathine penicillin G injection /
Christine Cruz-Conducto [and four others]
Rheumatic fever (RF) and rheumatic heart disease (RHD) in the Philippines remain to be significant causes of morbidity and mortality among children. This study aimed to determine serum penicillin levels of benzathine penicillin G (BPG) in Filipino children with RF/RHD after intramuscular administration of 1.2 M units of BPG after 21 and 28 days using the high performance liquid chromatography (HPLC) and the disk diffusion (DD) assay (utilizing the minimum inhibitory concentration for penicillin). Levels were determined at the following intervals: 0,7,14,21 and 28 days after the administration of BPG. A total of 49 patients were recruited from a tertiary hosptials R.H.D. Clinic of the pediatric Out-patient department. Thirty patients were included in the DD assay and 32 in the HPLC method with 13 patients common to both methods. The serum BPG levels peaked at day 14 in the HPLC method and 7 in the DD method. With the disk diffusion method, levels were still detectable on day 28; but with the HPLC method, PBG levels were not detectable in 15.3% on day 21 an in 53.6% on day 28. These data would suggest that BPG levels in majority of cases reaches zero level before day 28. We therefore recommend that BPG be administered every 21 days.