Acute uric acid nephropathy (AUAN, also acute urate nephropathy) is a rapidly worsening (decreasing) kidney function (acute kidney injury) that is caused by high levels of uric acid in the urine (hyperuricosuria). Causes
Acute uric acid nephropathy is usually seen as part of the acute tumour lysis syndrome in patients undergoing chemotherapy or radiation therapy for the treatment of malignancies with rapid cell turnover, such as leukemia and lymphoma. It may also occur in these patients before treatment is begun, due to spontaneous tumor cell lysis (high incidence in Burkitts lymphoma). Acute uric acid nephropathy can also be caused by an acute attack of gout. Pathophysiology
Acute uric acid nephropathy is caused by deposition of uric acid crystals within the kidney interstitium and tubules, leading to partial or complete obstruction of collecting ducts, renal pelvis, or ureter. This obstruction is usually bilateral, and patients follow the clinical course of acute kidney failure. Diagnosis
The picture of acute kidney failure is observed: decreased urine production and rapidly rising serum creatinine levels. Acute uric acid nephropathy is differentiated from other forms of acute kidney failure by the finding of a urine uric acid/creatinine ratio > 1 in a random urine sample. Prevention
Patients at risk for acute uric acid nephropathy can be given allopurinol or rasburicase (a recombinant urate oxidase) prior to treatment with cytotoxic drugs. Treatment
Treatment is focused on preventing deposition of uric acid within the urinary system by increasing urine volume with potent diuretics such as furosemide.
Ethinylestradiol/norethisterone (EE/NET), or ethinylestradiol/norethindrone, is a combination birth control pill which contains ethinylestradiol (EE), an estrogen and norethisterone (NET), a progestin. It is used for birth control, symptoms of menstruation, endometriosis, and menopausal symptoms. Other uses include acne. It is taken by mouth. Some preparations of EE/NET additionally contain an iron supplement in the form of ferrous fumarate.Side effects can include nausea, headache, blood clots, breast pain, depression, and liver problems. Use is not recommended during pregnancy, the initial three weeks after childbirth, and in those at high risk of blood clots. It, however, may be started immediately after a miscarriage or abortion. Smoking while using combined birth control pills is not recommended. It works by stopping ovulation, making the uterus not suitable for implantation, and making the mucus at the opening to the cervix thick.This combination pill was approved for medical use in the United States in 1964. It is on the World Health Organizations List of Essential Medicines. It is available as a generic medication. It is marketed under a large number of brand names. In 2020, it was the 45th most commonly prescribed medication in the United States, with more than 14 million prescriptions. See also
Mestranol/norethisterone
Oral contraceptive formulations
List of combined sex-hormonal preparations


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