Late latent syphilis in a patient with end-stage renal disease and presumptive penicillin allergy.

Purpose Pharmacotherapy challenges in a case of late latent syphilis complicated by end-stage renal disease and presumptive penicillin allergy are described. Summary A 58-year-old white woman was admitted to the hospital for symptoms including altered mental status, shortness of breath, and chest pain. The initial workup isolated syphilis immunoglobulin G antibody. A treponemal test was reactive, and a nontreponemal test was nonreactive; analysis of cerebrospinal fluid did not indicate neurosyphilis. The patient was diagnosed as having late latent syphilis of unknown duration, for which the standard treatment is intramuscular penicillin G benzathine 2.4 million units once weekly for three weeks. Given the patient’s advanced renal disease and other serious comorbidities, there were concerns about the potential need for renal dosage adjustment and repeated desensitization. However, given the slow absorption and long half-life of penicillin G and published data indicating its safe use in the context of hemodialysis, the treating clinicians decided to proceed with penicillin G therapy at the usual dose after an oral penicillin desensitization protocol; repeat desensitization before two subsequent injections was not performed. The patient completed the full course of penicillin G without incident. Notably, skin testing was not performed to definitively establish penicillin allergy. Microbiological testing to determine a cure of syphilis was not performed. Conclusion After the completion of an oral desensitization protocol, the standard three-dose regimen of intramuscular penicillin G for late latent syphilis was safely administered to a hemodialysis patient without dosage adjustment or repeated desensitization.