The tolerance for zidovudine plus thrice weekly or daily trimethoprim-sulfamethoxazole with and without leucovorin for primary prophylaxis in advanced HIV disease. California Collaborative Treatment Group.
OBJECTIVE
Trimethoprim-sulfamethoxazole (TMP/SMX) is the preferred agent for prophylaxis of Pneumocystis carinii pneumonia (PCP) in patients with HIV infection, but frequent adverse events limit its usefulness. Intermittent dosing and supplementation with leucovorin have been tried in attempts to improve tolerance. We evaluated these strategies in persons with advanced HIV disease.


METHODS
One hundred seven patients were enrolled. All had HIV infection, < 200 CD4+ lymphocytes per mm3, and no history of PCP. Fifty-two were randomized to TMP/SMX twice daily (BID); of these, 26 were randomized to leucovorin with each dose. Fifty-five patients were randomized to TMP/SMX (BID) 3 times per week; of these, 27 were randomized to leucovorin with each dose. All patients took zidovudine concurrently.


RESULTS
The 24-week risk of discontinuation due to protocol-defined limiting toxicity was 24% with thrice-weekly TMP/SMX versus 42% with daily TMP/SMX (risk ratio 0.4; 95% CI 0.2 to 1.0). The risks of discontinuation for any reason were 41% and 59% (risk ratio 0.4; 95% CI 0.2 to 0.8). Clinical toxicity, such as headache and gastrointestinal distress, accounted for the observed difference in tolerance between dosing regimens. The 24-week risk of discontinuation due to protocol-defined toxicity was 33% in both the leucovorin and non-leucovorin groups (risk ratio 1.1; 95% CI 0.5 to 2.5). The risks of discontinuation for any reason were 53% and 47% (risk ratio 0.8; 95% CI 0.3 to 1.7).


CONCLUSIONS
Intermittent therapy with TMP/SMX BID thrice weekly is better tolerated than daily BID therapy. Leucovorin use does not improve tolerance for chronic TMP/SMX dosing in AIDS, even among patients taking tablets daily.
Department of Medicine, University of California San Diego, La Jolla.
S A
SA
Bozzette
D
D
Forthal
F R
FR
Sattler
C
C
Kemper
D D
DD
Richman
J G
JG
Tilles
J
J
Leedom
J A
JA
McCutchan
D017088:AIDS-Related Opportunistic Infections / Q000517:prevention & control* / Q000821:virology; D000293:Adolescent; D000328:Adult; D001855:Bone Marrow Diseases / Q000139:chemically induced / Q000517:prevention & control*; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D005260:Female; D015658:HIV Infections / Q000188:drug therapy; D006801:Humans; D002955:Leucovorin / Q000627:therapeutic use*; D008297:Male; D011020:Pneumonia, Pneumocystis / Q000517:prevention & control* / Q000821:virology; D016016:Proportional Hazards Models; D016896:Treatment Outcome; D015662:Trimethoprim, Sulfamethoxazole Drug Combination / Q000008:administration & dosage / Q000009:adverse effects*; D015215:Zidovudine / Q000009:adverse effects* / Q000627:therapeutic use
D015215:Zidovudine; D015662:Trimethoprim, Sulfamethoxazole Drug Combination; D002955:Leucovorin