Randomized trial of trimethoprim-sulfamethoxazole versus pyrimethamine-sulfadiazine for therapy of toxoplasmic encephalitis in patients with AIDS. Italian Collaborative Study Group. Open-label randomized trial of oral trimethoprim-sulfamethoxazole, doxycycline, and chloramphenicol compared with trimethoprim-sulfamethoxazole and doxycycline for maintenance therapy of melioidosis. Ofloxacin versus trimethoprim/sulfamethoxazole in the treatment of uncomplicated urinary tract infection.
The aim of the present pilot study was to compare the efficacy and safety of trimethoprim (TMP) and sulfamethoxazole (SMX) with those of the standard therapy pyrimethamine (P)-sulfadiazine (S) for the treatment of toxoplasmic encephalitis in patients with AIDS. This was a pilot, multicenter, randomized, and prospective study. Patients were randomly assigned to receive TMP (10 mg/kg of body weight/day) and SMX (50 mg/kg/day) or P (50 mg daily) and S (60 mg/kg/day) as acute therapy (for 4 weeks) and then as maintenance therapy for 3 months at half of the original dosage. Seventy-seven patients were enrolled and randomized to the study: 40 patients were treated with TMP-SMX and 37 were treated with P-S. There was no statistically significant difference in clinical efficacy during acute therapy. In contrast, patients randomized to TMP-SMX appeared more likely to achieve a complete radiologic response after acute therapy. Adverse reactions were significantly more frequent in patients treated with P-S, and skin rash was the most common adverse event noted in these patients. In conclusion, the results of the study suggest that TMP-SMX appears to be a valuable alternative to P-S, in particular in patients with opportunistic bacterial infections. Melioidosis (infection caused by Burkholderia pseudomallei) requires a prolonged course of oral antibiotics following initial intravenous therapy to reduce the risk of relapse after cessation of treatment. The current recommendation is a four-drug regimen (trimethoprim [TMP], sulfamethoxazole [SMX], doxycycline, and chloramphenicol) and a total treatment time of 12 to 20 weeks. Drug side effects are common; the aim of this study was to compare the efficacy and tolerance of the four-drug regimen with a three-drug regimen (TMP-SMX and doxycycline). An open-label, randomized trial was conducted in northeast Thailand. A total of 180 adult Thai patients were enrolled, of which 91 were allocated to the four-drug regimen and 89 to the three-drug regimen. The trial was terminated early due to poor drug tolerance, particularly of the four-drug regimen. The culture-confirmed relapse rates at 1 year were 6.6% and 5.6% for the four- and three-drug regimens, respectively (P = 0.79). The three-drug regimen was better tolerated than the four-drug regimen; 36% of patients receiving four drugs and 19% of patients receiving three drugs required a switch in therapy due to side effects (P = 0.01). The duration of oral therapy was significantly associated with relapse; after adjustment for confounders, patients receiving less than 12 weeks of oral therapy had a 5.7-fold increase of relapse or death. A combination of TMP-SMX and doxycycline is as effective as and better tolerated than the conventional four-drug regimen for the oral treatment phase of melioidosis. A multicenter randomized study was conducted to compare the efficacy and safety of ofloxacin with that of trimethoprim/sulfamethoxazole (TMP/SMX) in the treatment of uncomplicated urinary tract infection in adults. Patients were randomized to receive either oral ofloxacin 200 mg daily for three days (102 patients), or oral TMP/SMX 160 mg/800 mg twice daily for seven days (100 patients). The pathogen was eradicated in 73 (97.3%) of the 75 evaluable patients receiving ofloxacin and in 66 (97.1%) of the 68 evaluable patients receiving TMP/SMX. The most frequently isolated pathogens were Escherichia coli, Klebsiella pneumoniae, and Proteus mirabilis. More urinary pathogens were susceptible to ofloxacin than to TMP/SMX, although this difference was not statistically significant. The clinical cure rate for patients receiving ofloxacin was 93.3%, with 4% improved and 2.7% failed. For patients receiving TMP/SMX, the clinical cure rate was 86.4%, with 12.1% improved and 1.5% failed. Side effects were reported by 29.7% of the patients receiving ofloxacin and by 40.4% of the patients receiving TMP/SMX. Drug-related adverse experiences, as determined by the investigators, occurred in 5% of the ofloxacin patients and in 15.2% of the TMP/SMX patients, a statistically significant difference. No patients receiving ofloxacin, compared with three patients receiving TMP/SMX, discontinued therapy because of an adverse reaction. These results indicate that short-course ofloxacin is as effective as TMP/SMX in the treatment of uncomplicated urinary tract infection. Ofloxacin therapy is also better tolerated than TMP/SMX.
The available evidence fails to identify any one superior regimen for the treatment of TE. The choice of therapy will often be directed by available therapy. Given the current evidence, TMP-SMX appears to be an effective alternative therapy for TE in resource-poor settings where P+S are not available.