Penicillin V Potassium Salt

One hundred five Staphylococcus aureus infections occurring in 79 children who were seen in a private office practice were evaluated for response to antibiotic therapy. The value of in vitro disk susceptibility testing in directing antibiotic selection in treatment failures was also examined. Of the total episodes studied, the types of infection studied included vesicular pyoderma (48%), secondary pyoderma (13%), bullous pyoderma (5%), furunculosis (14%), carbunculosis (12%), cellulitis (3%), suppurative otitis media (4%), and paronychia (2%). Comparative treatment efficacy was obtained with perioral erythromycin estolate and erythromycin ethylsuccinate, cefaclor and cephalexin, and clindamycin hydrochloride and dicloxacillin sodium. Penicillin V potassium, ampicillin, and topical bacitracin were generally ineffective. In 23 patients, 27/105 infections were initial treatment failures. Antibiotic disk susceptibility testing predicted these clinical failures and/or the antibiotic that would produce a clinical response in 21 of these 23 patients, suggesting that this office procedure can be of considerable value.

A liquid chromatographic method for the determination of penicillin V potassium in tablets was collaboratively studied by 7 laboratories. The method uses an octadecyl silane reverse-phase column, a mobile phase of acetonitrile-methanol-0.01 M potassium phosphate monobasic (21 + 4 + 75 v/v/v), photometric detection at 225 nm, and sulfadimethoxine as an internal standard. Each collaborator received 6 samples: powdered composites of 2 commercial tablet preparations and 1 synthetic tablet powder mixture, each with blind duplicates. The mean repeatability and reproducibility relative standard deviations for commercial samples were, respectively, 1.10 and 1.46% (250 mg dosage), and 0.84 and 2.82% (500 mg dosage). The average standard recovery from the synthetic formulation was 99.1%, with repeatability and reproducibility relative standard deviations of 1.30 and 3.66%, respectively. The method has been adopted official first action.

An a priori pharmacokinetic/pharmacodynamic (PK/PD) target of 40% daily time above the MIC (T >MIC; based on the MIC(90) of 0.06 microg/ml for Streptococcus pyogenes reported in the literature) was shown to be achievable in a phase 1 study of 23 children with a once-daily (QD) modified-release, multiparticulate formulation of amoxicillin (amoxicillin sprinkle). The daily T >MIC achieved with the QD amoxicillin sprinkle formulation was comparable to that achieved with a four-times-daily (QID) penicillin VK suspension. An investigator-blinded, randomized, parallel-group, multicenter study involving 579 children 6 months to 12 years old with acute streptococcal tonsillopharyngitis was then undertaken. Children were randomly assigned 1:1 to receive either the amoxicillin sprinkle (475 mg for ages 6 months to 4 years, 775 mg for ages 5 to 12 years) QD for 7 days or 10 mg/kg of body weight of penicillin VK QID for 10 days (up to the maximum dose of 250 mg QID). Unexpectedly, the rates of bacteriological eradication at the test of cure were 65.3% (132/202) for the amoxicillin sprinkle and 68.0% (132/194) for penicillin VK (95% confidence interval, -12.0% to 6.6%). Thus, neither antibiotic regimen met the minimum criterion of > or =85% eradication ordinarily required by the U.