Renal failure, acute creatinine clearance

O Equations to estimate creatinine clearance that incorporate a single creatinine concentration (e.g., Cockcroft-Gault) may underestimate or overestimate kidney function depending on whether acute renal failure is worsening or resolving. 

The initial dose of allopurinol is based on the patient s renal function. Patients with creatinine clearances of 50 mL/minute or less should receive a starting dose of less than 300 mg/day to minimize adverse effects. The relationship between dose of allopurinol and its most severe side effects is controversial. However, the dose can be adjusted upward as needed and tolerated. It is reasonable to reduce the dose temporarily in patients who develop reversible acute renal failure. 

Abnormal renal function, including acute renal failure, decreased serum creatinine clearance, and increased serum creatinine... 

Carvounis CP, Nisar S, Guro-Razuman S (2002) Significance of the fractional excretion of urea in the differential diagnosis of acute renal failure. Kidney Int 62 2223-2229 Dunn SR, Qi Z, Bottinger EP et al. (2004) Utility of endogenous creatinine clearance as a measure of renal function in mice. Kidney Int 65 1959-1967... 

A 43-year-old woman with rheumatoid arthritis developed dizziness having taken celecoxib 200 mg/day for 2 weeks. At the start of treatment she had normal renal function (104). Her serum creatinine was 670 pmol/l (7.4 mg/dl) and blood urea nitrogen 30 mmol/1 (90 mg/dl). Creatinine clearance was 16 ml/minute. Urinalysis was normal and casts were not present. Urinary chemical analysis showed a sodium concentration of 18 mmol/1, a fractional excretion of sodium of 0.3, and a renal failure index of 0.493, consistent with prerenal acute renal insufficiency. Celecoxib was withdrawn. Although her renal function then improved, her serum creatinine was still abnormal (4.7 mg/dl) 1 month later. 

TABLE 41—7. Estimation of Creatinine Clearance in Patients with Acute Renal Failure... 

Often defined as failure of >500 mg amphotericin B, initial renal insufficiency (creatinine >2.5 mg/dL or creatinine clearance <25 mL/min), a significant increase in creatinine (to 2.5 mg/dL for adults or 1.5 mg/dL for children), or severe acute administration-related toxicity. 

Acute renal failure developed in a woman taking captopril when she started to take aspirin for arthritis. Renal function improved when both were stopped. However, in a re-analysis of data from the Hypertension Optimal Treatment (HOT) study, long-term low-dose aspirin 75 mg daily had no effect on changes in serum creatinine, estimated creatinine clearance or the number of patients developing renal impairment, when compared with placebo. Of 18 790 treated hypertensive patients, 41% receiv an ACE inhibitor. ... 

A study in 4 healthy subjects found that indometacin 150 mg daily given with triamterene 200 mg daily over a 3-day period reduced the creatinine clearance in 2 subjects by 62% and 72%, respectively. Renal function returned to normal after a month. Indometacin alone caused an average 10% fall in creatinine clearance, but triamterene alone caused no consistent change in renal function. No adverse reactions were seen in 18 other subjects treated in the same way with indometacin and furosemide, hydrochlorothiazide or spironolactone. Five patients are reported to have rapidly developed acute renal failure after receiving indometacin and triamterene, either concurrently or sequentially. " ... 

Relative contraindications include unacceptable medical risk for isolation, unmanageable coagulation disturbance, severe reparative dysfunction, acute or severe chronic renal failure (creatinine clearance below 30 ml/min), liver cirrhosis greater than Child B, leukocytes below 1500 GPT/1, thrombocytes below 50,000 GPT/1. 

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