Acute kidney injury due to anabolic steroid and vitamin supplement abuse: report of two cases and a literature review.

BACKGROUND: The use of anabolic steroids and vitamin supplements has reached alarming proportions in the last decades. Adverse effects have been documented and include virilization, feminization, adverse lipid profile, psychiatric disorders, cardiac and liver disease. Acute kidney injury (AKI) is not frequently described. The purpose of this study is to report two cases of AKI associated with anabolic steroid and vitamin supplement abuse. CASE REPORT: Two men, aged 21 and 30 years, presented to the Emergency Department with abdominal pain, nausea and vomiting. They reported the use of anabolic steroids and veterinary supplements with vitamins A, D and E. Laboratory tests showed AKI (serum urea 79 and 52 mg/dl, serum creatinine 3.9 and 1.9 mg/dl) and hypercalcemia (calcium 13.2 and 11 mEq/l). Kidney biopsies showed inflammatory interstitial nephritis and acute tubular necrosis. Treatment consisted of vigorous hydration with simultaneous use of furosemide and discontinuation of the vitamins and anabolic substances, and resulted in recovery of renal function. CONCLUSIONS: AKI is an important complication of anabolic steroid and vitamin supplement abuse. The exact pathophysiology of this type of AKI remains unclear. The main cause of renal dysfunction in these cases seems to be the vitamin D intoxication and drug-induced interstitial nephritis. It is mandatory to start early treatment for serious hypercalcemia, with vigorous venous hydration, diuretics and corticosteroids.

Intestinal permeability and malabsorption of rifampin and isoniazid in active pulmonary tuberculosis

Low antimycobacterial drug concentrations have been observed in tuberculosis (TB) patients under treatment. The lactulose/mannitol urinary excretion test (L/M), normally used to measure intestinal permeability, may be useful to assess drug absorption. The objective of this research was to study intestinal absorptive function and bioavailability of rifampin and isoniazid in TB patients. A cross sectional study was done with 41 patients and 28 healthy controls, using the L/M test. The bioavailabilities of rifampin (R) and isoniazid (H) were evaluated in 18 patients receiving full doses. Urinary excretion of mannitol and lactulose, measured by HPLC, was significantly lower in TB patients. The serum concentrations of the drugs were below the expected range for R (8-24 mcg/mL) or H (3-6 mcg/mL) in 16/18 patients. Analyzing the drugs individually, 12/18 patients had low serum concentrations of R, 13/18 for H and 8/18 for both drugs. We suggest that there is a decrease in the functional absorptive area of the intestine in TB patients, which would explain the reduced serum concentrations of antituberculosis drugs. There is a need for new approaches to improve drug bioavailability in TB patients.

Intestinal permeability and malabsorption of rifampin and isoniazid in active pulmonary tuberculosis.

Low antimycobacterial drug concentrations have been observed in tuberculosis (TB) patients under treatment. The lactulose/mannitol urinary excretion test (L/M), normally used to measure intestinal permeability, may be useful to assess drug absorption. The objective of this research was to study intestinal absorptive function and bioavailability of rifampin and isoniazid in TB patients. A cross sectional study was done with 41 patients and 28 healthy controls, using the L/M test. The bioavailabilities of rifampin (R) and isoniazid (H) were evaluated in 18 patients receiving full doses. Urinary excretion of mannitol and lactulose, measured by HPLC, was significantly lower in TB patients. The serum concentrations of the drugs were below the expected range for R (8-24 mcg/mL) or H (3-6 mcg/mL) in 16/18 patients. Analyzing the drugs individually, 12/18 patients had low serum concentrations of R, 13/18 for H and 8/18 for both drugs. We suggest that there is a decrease in the functional absorptive area of the intestine in TB patients, which would explain the reduced serum concentrations of antituberculosis drugs. There is a need for new approaches to improve drug bioavailability in TB patients.