Bactrim (Trimethoprim/sulfamethoxazole) Desensitization

7/09/04

Question: How is desensitization to bactrim (Trimethoprim/sulfamethoxazole) accomplished for patients who have shown an allergic reaction to this drug?

Link Directly to Fulltext Article at Publisher

<3>

Unique Identifier:9972526

Authors: Koopmans PP. Burger DM.

Institution: Department of General Internal Medicine, University Hospital Nijmegen St. Radboud, The Netherlands.

Title: Managing drug reactions to sulfonamides and other drugs in HIV infection: desensitization rather than rechallenge?. [Review] [43 refs]

Source: Pharmacy World & Science. 20(6):253-7, 1998 Dec.

Abstract: Drug reactions in patients with HIV infection, e.g. fever or rash, are a frequently occurring clinical problem. These side effects particularly are observed with sulfonamides; however, many other drugs have also shown to induce allergic reactions when given to patients with HIV infection. The production of hydroxylamines has been put forward as one of the explanations for these high incidence of reactions on drugs. Since sulfonamides are the first choice of therapy for the treatment and prophylaxis of Pneumocystis carinii pneumonia, several strategies have been developed to circumvent drug reactions. In general rechallenge or desensitization are recommended in literature. This article discusses the results and risks of rechallenge and desensitization with sulfonamides or other drugs, as mentioned in the literature. Furthermore preliminary results of rechallenge with a sulfonamide, which is not metabolized into hydroxylamines, are presented. From the data in the literature it is concluded that desensitization should be preferred to rechallenge. [References: 43]

<5>

Unique Identifier:9617304

Authors: Ryan C. Madalon M. Wortham DW. Graziano FM.

Institution: University of Wisconsin Hospital and Clinics, Department of Internal Medicine, Madison 53792-3244, USA.

Title: Sulfa hypersensitivity in patients with HIV infection: onset, treatment, critical review of the literature. [Review] [17 refs]

Source: WMJ. 97(5):23-7, 1998 May.

Abstract: Trimethoprim/Sulfamethoxazole is the most effective medication used in both the treatment and prevention of Pneumocystis carinii pneumonia (PCP) in patients with HIV/AIDS. Its use, however, is accompanied by a high incidence of adverse reactions, especially fever, myalgia and rash (sulfa hypersensitivity). In a group of our patients, we have examined the clinical parameters at the time of onset of sulfa hypersensitivity, and the success of a desensitization protocol for this adverse event. We also have performed a comprehensive review of the literature on sulfa hypersensitivity and have compared our results to those previously reported in the literature. Our findings indicate that the sulfa hypersensitivity reaction is more likely to develop in patients with advanced disease and that desensitization can restore tolerability to the drug in approximately two thirds of those who attempt it. [References: 17]

<7>

Unique Identifier:8835054

Authors: Cortese LM. Soucy DM. Endy TP.

Institution: Henry M Jackson Foundation for the Advancement of Military Medicine, Walter Reed Army Medical Center, Washington, DC, USA.

Title: Trimethoprim/sulfamethoxazole desensitization. [Review] [10 refs]

Source: Annals of Pharmacotherapy. 30(2):184-6, 1996 Feb.

Abstract: Although alternative therapy for PCP remains limited, the role of TMP/SMX desensitization becomes increasingly important in patients with AIDS. Various successful desensitization protocols have been described in this article. As there are no established guidelines, it appears that the desensitization procedure can occur in small successive doses given each day or one small dose given daily. An evaluation of the severity of allergic reaction can be used to determine the type of dosing regimen. We believe that protocols starting with low doses and slow titration to full-dose therapy, as used at our institution, should be efficacious. Monitoring of the patient after the desensitization procedure should continue, as sensitivity may reoccur. In addition, while the patient is undergoing desensitization, some investigators recommend that alternative therapy be continued until full-dose TMP/SMX therapy is achieved. Also, it is important to realize that once a patient is successfully desensitized, medication compliance must be maintained because, theoretically, reexposure to the drug after a lapse in therapy may result in hypersensitivity reactions. Therefore, this procedure and the possibility of serious adverse effects, such as Stevens-Johnson syndrome and anaphylaxis, should be evaluated carefully and discussed thoroughly with each patient prior to initiation of therapy. Finally, a study of sufficient size should be performed to evaluate the efficacy of desensitization regimens and establish specific dosing guidelines. [References: 10] CAS Registry/EC Number 0 (Anti-Infective Agents). 8064-90-2 (Trimethoprim-Sulfamethoxazole Combination).

 1.9087.1.155