Drugs in kidney diseases . Shiva Seyrafian M.D. Nephrologist 1391/2/30- - 19/5/2012. Drugs and the Kidney. Drugs and the normal kidney Drugs toxic to the kidney Prescribing in kidney disease Case presentation. Normal Kidney Function . 1 Extra Cellular Fluid Volume control
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(vitamin D3 metabolism)
Patients are asymptomatic or may have flank pain, hematuria, pyuria and crystaluria.
Patients should not take NSAIDs prior to procedures that involve the administration of iodinated contrast media.
All NSAIDs, including topically administered forms, should be terminated in patients suspected of having NSAID-induced acute interstitial nephritis. Although there is no definitive evidence that corticosteroid therapy is beneficial in this setting, a course of prednisone may be considered in patients whose renal failure persists more than one to two weeks after the NSAID has been discontinued.
The primary benefit of nonionic contrast agents, whether low or iso-osmolal, is seen in high-risk patients (eg, serum creatinine ≥1.5 mg/dL [132 micromol/L] or a GFR <60 mL/min per 1.73 m2), particularly if they are diabetic.
As a result, these agents should be used instead of ionic high osmolal agents.
Incidence: zero to over 50 percent
The use, if clinically possible, of ultrasonography, magnetic resonance imaging or CT scanning without radiocontrast agents, particularly in high-risk patients.
The use of lower doses of contrast and avoidance of repetitive studies that are closely spaced (within 48 to 72 hours). Very small amounts of contrast (<10 mL) have been safely used in patients with advanced kidney disease for examination of poorly maturing arteriovenous fistula.
Avoidance of volume depletion or nonsteroidalantiinflammatory drugs, both of which can increase renal vasoconstriction.
The administration of intravenous saline or possibly sodium bicarbonate.
The administration of the antioxidant acetylcysteine.
The use of selected low or iso-osmolal nonionic contrast agents.
There are two major concerns:
Factors can potentiate renal dysfunction:
Triamterene is a potential nephrotoxin, frequently inducing crystalluria and cast formation, and rarely causing stone formation or reversible acute renal failure.
The excretion of triamterene crystals and granular casts occurs in as many as one-half of patients. this finding is not seen with amiloride.
Triamterene may contribute to 1 in every 200 to 250 stones.
Reversible acute renal failure is another rare problem with triamterene (but not other potassium-sparing diuretics). Two different mechanisms have been described: intratubular obstruction by crystals; and concurrent therapy with a NSAID.
Diagnosis-Lead may be measured in whole blood, bone, and, following administration of a chelating agent, urine. If the blood lead level is greater than 10 mcg/dL (0.48 micromol/L), levels should be rechecked four weeks after the identified source of lead exposure is eliminated.
Drugs with MW >500 daltons poorly cleared by conventional HD membranes.
Protein or tissue binding or lipid soluble are not dialyzed properly.
For drugs not removed by HD, it is unusual to be removed by peritoneal dialysis.
High-flux membranes (porous) are more permeable to drugs.
TABLE 57-2 -- Drugs That Have Active or Toxic Metabolites in Dialysis Patients
TABLE 57-2-- Drugs That Have Active or Toxic Metabolites in Dialysis Patients cont…..
QuinidineSerotonin reuptake inhibitorsSpironolactoneSulfonylureasSulindac
T ½ often prolonged