Lack of effect of warfarin on uric acid concentration.

Uric acid concentrations reportedly are increased in patients being treated with warfarin. We measured uric acid in 40 patients before and during warfarin administration. The mean pre- and post-warfarin uric acid concentrations for our patients were 0.39 mmol/L and 0.40 mmol/L, respectively, not a significant difference. Further observations of hyperuricemic patients started on warfarin are needed to prove that their risk of gout is not increased.

Resistance among fecal flora of patients taking sulfamethoxazole-trimethoprim or trimethoprim alone.

Because of the widespread occurrence of resistance to sulfonamides among Enterobacteriaceae, some researchers have suggested using trimethoprim (TMP) alone instead of the combination sulfamethoxazole-trimethoprim (SMX-TMP) in treating infections with TMP-susceptible organisms. To answer whether SMX-TMP suppresses the emergence of resistant organisms compared with TMP alone, quantitative fecal cultures were made for total and TMP-resistant organisms before, during, and after SMX-TMP (800/160 mg twice a day) or TMP (200 or 100 mg twice a day) was given to 48 patients for 4 weeks in a prospective, randomized study. All three regimens left anaerobes intact and reduced the total aerobic coliform fecal flora by approximately 4 logs throughout the 4-week treatment period. In 11 of 19 (58%) patients taking TMP 200 mg twice daily, TMP-resistant organisms emerged or increased during therapy (P less than 0.01, compared with none of the 12 controls), whereas in only 4 of 18 (22%) patients on SMX-TMP did TMP-resistant organisms increase. These TMP-resistant organisms increased by less than 1 log and were predominantly Pseudomonas and Acinetobacter species. In only one instance did an SMX-TMP-resistant Escherichia coli strain emerge after 4 weeks of SMX-TMP therapy. The slight increase in Pseudomonas and Acinetobacter species seen with TMP alone in this study raises a potential risk of giving TMP alone in settings where these organisms may cause serious infections, as in immunosuppressed patients.

Multiple use of disposable insulin syringe-needle units.

Fourteen insulin-dependent diabetics were asked to use their insulin syringe-needle units three times in succession to determine the efficacy and safety of this practice. The mean duration of time each patient participated in the study was 20.4 weeks, and a total of 2,000 injections were taken. No signs of infections at the injection site were observed. Multiple use of disposable insulin syringe-needle units appears to be safe and cost beneficial.