Randomized trial of trimethoprim-sulfamethoxazole versus pyrimethamine-sulfadiazine for therapy of toxoplasmic encephalitis in patients with AIDS. Italian Collaborative Study Group. Pyrimethamine-clindamycin vs. pyrimethamine-sulfadiazine as acute and long-term therapy for toxoplasmic encephalitis in patients with AIDS. Treatment of toxoplasmic encephalitis in patients with AIDS. A randomized trial comparing pyrimethamine plus clindamycin to pyrimethamine plus sulfadiazine. The California Collaborative Treatment Group.
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. This European multicenter study compares the efficacy and tolerance of the combination of pyrimethamine-clindamycin (Pyr-Cm) with the standard therapy pyrimethamine-sulfadiazine (Pyr-Sdz) for the treatment of toxoplasmic encephalitis (TE) in patients with AIDS. Two hundred ninety-nine human immunodeficiency virus-infected patients with TE were randomly assigned to receive 50 mg of pyrimethamine daily combined with either 2,400 mg of clindamycin or 4 g of sulfadiazine for 6 weeks followed by maintenance therapy with 25 mg of pyrimethamine daily with either 1,200 mg of clindamycin or 2 g of sulfadiazine. An intent-to-treat analysis showed that Pyr-Cm was less effective than Pyr-Sdz; the overall risk of progression of TE was 1.84 times higher for patients receiving Pyr-Cm therapy. There was no statistically significant difference in efficacy during acute therapy, although the rate of crossover motivated by a lack of response was higher among Pyr-Cm recipients. The difference in efficacy was evidenced during the maintenance phase of treatment; the relapse rate was twice as high among patients in the Pyr-Cm group (P = .02). The rate of side effects due to both regimens was similar, although the toxic effects of Pyr-Cm led to fewer discontinuations of therapy than did those of Pyr-Sdz (11% vs. 30%, respectively; P = .001). Pyr-Sdz appears to be the most effective treatment of TE. Pyr-Cm is a valuable alternative but is less effective for long-term prevention of relapses. To compare pyrimethamine plus clindamycin (PC) to pyrimethamine plus sulfadiazine (PS) as a treatment for toxoplasmic encephalitis (TE) in patients with the acquired immunodeficiency syndrome (AIDS).
                Randomized, unblinded phase II, multicenter trial with provision for crossover for failure or intolerance of the assigned regimen.
                University hospitals.
                Eighty-four patients with presumptive TE were entered. Thirteen were excluded when they were found to have another diagnosis, and 12 were excluded because they did not meet entry criteria. The baseline characteristics in the remaining 26 patients randomized to PC and 33 randomized to PS were comparable.
                Patients were treated for 6 weeks with pyrimethamine and folinic acid plus either sulfadiazine or clindamycin. Clindamycin was given intravenously during the first 3 weeks.
                There was a trend toward greater survival in patients randomized to PS (hazard ratio, 3.25; 95% CI, 0.63 to 16.8; P = 0.13), but most study deaths were not directly related to TE. In contrast, patients randomized to PC appeared more likely to achieve complete clinical (odds ratio, 0.67; CI, 0.2 to 1.97; P greater than 0.2) and radiologic responses (odds ratio, 0.28; CI, 0.08 to 0.96; P = 0.02). Multivariate analysis revealed drug effects to be largely independent of other variables. Similar efficacy of the treatments was also suggested by a hazard analysis of resolution of abnormal mental status, fever, and headache. Skin rash was the most common adverse event in both treatment arms. Because of toxicity, six patients randomized to PC and 11 patients randomized to PS had to switch to the alternate treatment, but only three were unable to complete therapy after crossover.
                The results of several end points of efficacy, taken together, suggest that the relative efficacy of PC approximately equals that of PS. PC appears to be an acceptable alternative in patients unable to tolerate PS.
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.