Rapid Oral Desensitization to Trimethoprim-Sulfamethoxazole (TMP-SMZ): Use in Prophylaxis for Pneumocystis carinii Pneumonia in Patients with AIDS Who Were Previously Intolerant to TMP-SMZ

Abstract

Trimethoprim-sulfamethoxazole (TMP-SMZ) is the drug of choice as prophylaxis for Pneumocystis carinii pneumonia in patients with AIDS. However, adverse reactions ascribed to TMP-SMZ are common in such patients. We previously described a rapid method of oral TMP-SMZ desensitization in patients with AIDS and varying degrees of intolerance to the drug. To assess the feasibility, safety, and long-term clinical utility of our desensitization protocol, we retrospectively studied 22 consecutive patients who underwent desensitization. Prior to the procedure each of the study subjects had exhibited moderate to severe reactions to TMP-SMZ. Desensitization was successfully completed in 19 (86%) of the patients. The three patients for whom desensitization failed experienced chills and/or vomiting that resolved promptly with symptomatic therapy. One of the 19 patients was unavailable for long-term follow-up. Of the remaining 18 patients, three discontinued taking TMP-SMZ within 2 weeks of desensitization because of macular rash and fever. The other 15 (71%) of the evaluable patients tolerated both desensitization and subsequent prophylaxis and took TMP-SMZ for a mean of 14 months (in some cases, for as long as 41 months). None had P. carinii pneumonia while receiving TMP-SMZ. These results indicate that most patients who are presumed to be TMP-SMZ-intolerant can be rapidly desensitized with oral TMP-SMZ and subsequently receive the drug for protracted periods as effective prophylaxis for P. carinii pneumonia.

Safety and Efficacy of <i>Juniperus ashei</i> Sublingual-Swallow Ultra-Rush Pollen Immunotherapy in Cypress Rhinoconjunctivitis

“…Routes of administration that can be used in drug tolerance protocols include the oral, subcutaneous, and intravenous routes and even nasal or bronchial nebulization [26]. Good examples of the efficacy of these protocols have been reported in AIDS patients [27,28,29]. Although the mechanisms responsible for this tolerance to rush administration are unknown, it can be hypothesized that the mechanisms involved in conventional immunotherapy are subsequently activated, as illustrated by the marked increase of IgG4 production observed after 4 months in the present study.…”

Trimethoprim-Sulfamethoxazole Revisited

“…47,[50][51][52][53][54] Some adverse reactions seem to be dose related (rash, fever, liver enzyme abnormalities, and GI disturbances), while others seem to be independent of dose (neutropenia, anemia, and azotemia). 49 The treatment of HIV-infected patients with drug-associated hypersensitivity reactions remains controversial, with symptomatic treatment through the reaction 45,55 and gradual reintroduction of the drug (desensitization) 56,57 proving to be successful strategies.…”

A randomized, pilot trial comparing full versus escalating dose regimens for the desensitization of AIDS patients allergic to sulfonamides

“…Oral desensitization to this class of drugs has been effective in most cases (50% to 80%), but the best regimen to accomplish this remains to be determined [7][8][9][10][11][12]. In a previous experience with oral desensitization, we were able to successfully reintroduce sulfonamides to almost 80% of the patients, by using escalating doses [13].…”

“…Oral desensitization of AIDS patients allergic to sulfonamides has been attempted by using different doses or regimens, with a variable reported rate of success [6][7][8][9][10][11]. However, there are still answered questions about the impact of the type of desensitization www.infecto.org.br/bjid.htm regimen (full versus escalating doses) on the outcome of patients submitted to re-exposure to sulfonamides.…”