A 46-year-old woman suffering from systemic lupus erythematosus (SLE) develops hematuria and proteinuria. She was diagnosed with SLE four years ago and has been treated with hydroxychloroquine and prednisone. A renal biopsy is performed and shows diffuse proliferative glomerulonephritis. She is started on cyclophosphamide, and hydroxychloroquine is stopped. This new therapeutic regimen puts her at an increased risk for which of the following conditions?

Question

A 46-year-old woman suffering from systemic lupus erythematosus (SLE) develops hematuria and proteinuria.  She was diagnosed with SLE four years ago and has been treated with hydroxychloroquine and prednisone.  A renal biopsy is performed and shows diffuse proliferative glomerulonephritis.  She is started on cyclophosphamide, and hydroxychloroquine is stopped.  This new therapeutic regimen puts her at an increased risk for which of the following conditions?

Quizplus · Accepted Answer

Cyclophosphamide is an alkylating agent frequently used as an immunosuppressant in systemic lupus erythematosus (SLE), vasculitis and certain cancers. Regarding SLE, cyclophosphamide is reserved for patients with significant renal or central nervous system problems. Unfortunately, cyclophosphamide has many side effects. Serious side effects include acute hemorrhagic cystitis, bladder carcinoma, sterility, and myelosuppression. Hemorrhagic cystitis and bladder cancer are caused by acrolein, a bladder-toxic metabolite of cyclophosphamide. Drinking plenty of fluids, voiding frequently, and taking mesna are all helpful in preventing these complications. (Choice A) Cochlear dysfunction is a side effect of cisplatin and carboplatin, both of which may be used to treat testicular, ovarian and bladder cancer. Aminoglycosides also may cause cochlear dysfunction. (Choice B) Ethambutol and hydroxychloroquine have been implicated in causing optic neuritis. (Choice D) Toxic causes of peripheral neuropathy include phenytoin, isoniazid, vincristine, heavy metals, and heavy alcohol use. (Choice E) Digital vasospasm (Raynaud phenomenon) may be caused by beta-blockers and ergotamine. (Choice F) Amiodarone and lithium are associated with thyroid dysfunction. (Choice G) Gout is a side effect of cyclosporine. (Choice H) Although alcohol use and gallstones account for the majority of cases of acute pancreatitis, certain drugs have also been implicated. Cyclophosphamide is not commonly associated with pancreatitis. Educational objective: Long-term cyclophosphamide use is associated with the increased incidence of acute hemorrhagic cystitis and bladder carcinoma.

A 46-Year-Old Woman Suffering from Systemic Lupus Erythematosus (SLE) Develops