The role of distal third radius dual energy X-ray absorptiometry (DXA) and central DXA in evaluating for osteopenia and osteoporosis in men receiving androgen deprivation therapy for prostate cancer.

The authors assessed the use of distal third radius dual energy X-ray absorptiometry (DXA) concomitantly with central (hip and lumbar spine) DXA to identify men with osteopenia or osteoporosis receiving androgen deprivation therapy (ADT) for prostate cancer. Initial classification with central DXA demonstrated 60 (17%) normal, 187 (55%) osteopenic, and 96 (28%) osteoporotic patients. Sixteen of 60 (27%) normal patients were reclassified as osteopenic (14) or osteoporotic (2), and 20 of 187 (11%) osteopenic patients were reclassified as osteoporotic with the combination of central DXA plus distal third radius DXA. The difference in reclassification was statistically significant. The addition of distal third radius to central DXA scanning in men with bone loss associated with ADT identifies a statistically significant number of men being reclassified as having osteopenia or osteoporosis. Combined central and distal third radius DXA scanning should be considered routine in the evaluation of all men suspected of bone loss associated with ADT. This has specific significant clinical relevance because of the large number of men with nonevaluable central DXA studies. Fracture risk prediction and treatment recommendations based on this reclassification will need to be determined by follow-up studies.

Obstructive nephropathy secondary to sulfasalazine calculi.

The incidence of drug-induced stone disease is 0.44%. A 57-year-old woman with ulcerative colitis presented with obstructive nephropathy and pyelonephritis. She underwent cystoscopy, bilateral retrograde pyelography, and bilateral ureteral stent placement. A 6-cm bladder calculus and two 3-mm right distal ureteral calculi were discovered. Later, cystolithotomy was performed. The stone analysis demonstrated sulfapyridine, a sulfasalazine metabolite. Patients with inflammatory bowel disease can develop urolithiasis owing to acidic urine and low-volume urine production. Patients receiving aminosalicylates are at an increased risk of urolithiasis and may benefit from oral hydration and urinary alkalization.