Comparison of high and low doses of trimethoprim-sulfamethoxazole for primary prevention of toxoplasmic encephalitis in human immunodeficiency virus-infected patients.
To evaluate the influence of the dose of co-trimoxazole prophylaxis on the risk of toxoplasmosis in human immunodeficiency virus (HIV)-infected patients, we performed a nested case-control study of 32 patients with toxoplasmosis (case patients) and 64 patients without toxoplasmosis (control patients) who were matched by CD4 cell count and Toxoplasma gondii serostatus; these patients were from a cohort of 521 HIV-infected patients who underwent a diagnostic neuroimaging study between March 1993 and January 1997. Twenty-seven (84.4%) of 32 case patients and 33 (51.6%) of 64 control patients received low doses of co-trimoxazole, a finding associated with an adjusted odds ratio (OR) of 9.36 (95% confidence interval [CI], 2.05-42.75) and indicating 89% protective efficacy for high doses. Fifteen (46.9%) of 32 case patients and 16 (25%) of 64 control patients were exposed to rifampin (adjusted OR, 3.38; 95% CI, 1.08-10.61). These results indicate that high doses of co-trimoxazole appear to be more effective than low doses for lowering the risk of toxoplasmosis in HIV-infected patients and that rifampin therapy may reduce the efficacy of co-trimoxazole.
Ribera
E
E
Servicio de Enfermedades Infecciosas, Hospital General Vall d'Hebron, 08035 Barcelona, Spain. eribera@hg.vhebron.es.
Fernandez-Sola
A
A
Juste
C
C
Rovira
A
A
Romero
F J
FJ
Armadans-Gil
L
L
Ruiz
I
I
Ocaña
I
I
Pahissa
A
A
D017088:AIDS-Related Opportunistic Infections / Q000517:prevention & control; D000328:Adult; D000818:Animals; D000890:Anti-Infective Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D000904:Antibiotics, Antitubercular / Q000627:therapeutic use; D016022:Case-Control Studies; D004305:Dose-Response Relationship, Drug; D004359:Drug Therapy, Combination; D004660:Encephalitis / Q000150:complications / Q000469:parasitology / Q000517:prevention & control*; D005260:Female; D015658:HIV Infections / Q000150:complications / Q000188:drug therapy*; D006801:Humans; D008297:Male; D012293:Rifampin / Q000627:therapeutic use; D014122:Toxoplasma / Q000187:drug effects*; D016781:Toxoplasmosis, Cerebral / Q000150:complications / Q000517:prevention & control*; D016896:Treatment Outcome; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000008:administration & dosage* / Q000627:therapeutic use
D000890:Anti-Infective Agents; D000904:Antibiotics, Antitubercular; D015662:Trimethoprim, Sulfamethoxazole Drug Combination; D012293:Rifampin