A 53-year-old man with a history of systemic lupus erythematosus (SLE) presents with hematuria. A renal biopsy demonstrates proliferative glomerulonephritis and the patient is started on cyclophosphamide.
Which of the following conditions is this patient at risk for developing with the initiation of this medication?
A. Peripheral neuropathyHemorrhagic cystitis. Cyclophosphamide is a nitrogen mustard alkylating agent used to treat cancers and autoimmune disorders such as SLE and the vasculitides. With respect to SLE, cyclophosphamide is used primarily in patients with renal pathology. Side effects of cyclophosphamide include hemorrhagic cystitis, bladder cancer, and myelosuppression. Fortunately, patients can be administered mesna and encouraged to drink liberal amounts of fluids to prevent these complications. (A) Peripheral neuropathy is a toxic side effect of vincristine use. Other causes of peripheral neuropathy include phenytoin, alcohol, isoniazid, and antiretroviral therapy. (B) Hearing loss, specifically cochlear dysfunction, can be seen with cisplatin and carboplatin. Other causes of hearing loss include aminoglycosides. (D) Thyroid abnormalities can be seen with amiodarone (useful both in supraventricular arrhythmias and ventricular arrhythmias) as well as lithium (useful in the prophylactic treatment of bipolar disorder).