Setting: Tertiary care hospital in the Upper Midwest, United States.
Objective: Rapid desensitization to para-aminosalicylic acid (PAS) in a patient with previous hypersensitivity reaction and a review of published PAS desensitization protocols.
Design: Composition and implementation of a short-course PAS desensitization protocol for a 34-year-old woman with multidrug-resistant (MDR) pulmonary tuberculosis, incorporating published experiences of PAS desensitization over the past 50 years.
Results: We composed a protocol and successfully desensitized our patient to PAS (Paser granules). By starting with a low dose (50 mg), then doubling the PAS dose on each successive day, our patient was able to tolerate full dose in 1 week. No steroids were required and no adverse reactions were encountered. Previous published PAS desensitization protocols used starting doses of 10-500 mg, desensitization time ranges from 7 to 54 days and commonly used steroids or corticotropin.
Conclusion: Rapid desensitization to PAS can be successfully conducted within 1 week without the use of steroids or corticotropin. Given the limited number of drugs available for many patients with MDR-TB, desensitization to PAS is a valid alternative to drug discontinuation for patients with hypersensitivity reactions.