Nelfinavir desensitization

Antimicrobial Desensitization: A Review of Published Protocols

Antimicrobial desensitization represents a last-line option for patients with no alternative therapies, where the benefits of this intensive process must outweigh the potential harm from drug exposure. The goal of antimicrobial desensitization procedures is to establish a temporary state of tolerance to drugs that may otherwise cause hypersensitivity reactions. While no universal antimicrobial desensitization protocols exist, this review critically analyzes previously published desensitization protocols. The purpose of this review is to provide a greater insight for clinicians and institutions to ensure desensitization procedures are efficacious while minimizing potential for patient harm. With an increasing rate of antimicrobial resistance and the critical need to preserve antimicrobial agents, desensitization may represent another option in our antimicrobial stewardship toolkit.

Amprenavir-induced maculopapular exanthem followed by desensitization in a patient with late-stage human immunodeficiency virus

BACKGROUND

Amprenavir, a human immunodeficiency virus type 1 (HIV-1) protease inhibitor, is approved for the treatment of HIV infection in combination with other antiretroviral agents in treatment-naive and experienced patients. Amprenavir is generally well tolerated. However, cutaneous hypersensitivity reactions to amprenavir occur in up to 28% of patients, with treatment discontinuation required in 3% of cases.

OBJECTIVE

To report successful desensitization to amprenavir after the occurrence of a maculopapular exanthem in an HIV-infected patient with late-stage disease and limited antiretroviral treatment options.

METHODS

Incremental doses of 0.025, 0.1, 0.25, 1, 2.5, 7.5, 25, 50, 100, 300, 600, and 1,200 mg of amprenavir oral solution were administered via percutaneous endoscopic gastrostomy tube at 20- to 30-minute intervals.

RESULTS

The patient successfully tolerated amprenavir desensitization and has continued therapy without recurrence of rash at 19 months of follow-up.

CONCLUSION

Desensitization may permit the continued use of amprenavir in HIV-positive patients with a history of amprenavir-induced maculopapular eruptions who have limited alternate treatment options.

The abacavir hypersensitivity reaction: a review

BACKGROUND

Abacavir sulfate is a recent addition to the nucleoside reverse-transcriptase inhibitor class of antiretroviral agents used in the treatment of HIV infection. It is approved for use in combination with other antiretroviral agents. Its tolerability has been studied, but the overall clinical relevance of the findings has yet to be determined.

OBJECTIVES

This review investigates available data on the abacavir hypersensitivity reaction (HSR) and provides a clinical perspective on maximizing this agent's tolerability and effective incorporation into antiretroviral regimens.

METHODS

Relevant data were identified through MEDLINE and AIDSLINE searches of the English-language literature from 1966 through 2002 using the terms abacavir and 1592U89, the investigational new drug designation for abacavir. The reference lists of identified articles were searched for additional documents. Additional information was obtained from the US Food and Drug Administration and the drug's manufacturer.

RESULTS

The abacavir HSR occurs in <5% of all patients started on therapy; the incidence appears to be unaffected by specific demographic characteristics or disease stage. Accurate diagnosis and appropriate patient education are essential, because reintroduction of abacavir in a patient with a history of possible HSR has been shown to result in a profound worsening of symptoms, including acute, severe hypersensitivity syndrome and possible death-even with aggressive treatment. Careful evaluation is necessary to distinguish an HSR from other manifestations of antiretroviral therapy. Despite the risk of HSR, compared with other anti-HIV medications, abacavir has demonstrated an overall favorable adverse-event profile.

CONCLUSIONS

The risk of abacavir HSR must be taken into consideration when selecting initial antiretroviral therapy for patients with HIV infection. Careful, appropriate evaluation is necessary to rule out an HSR and determine whether the medication can be continued.