Pharm Study Guide Assignment 2

. How will renal insufficiency affect drug elimination? The kidney is the primary organ of excretion for most drugs. The general theme of metabolism is to produce drug metabolites that are more water Soluble and more easily removed by the kidneys. The kidney Can then remove these substances from the plasma and excrete them in the urine. The kidney is a Complex organ with Several important functions, including excretion of waste products and maintenance of fluid and electrolyte balance in the body. Glomerular filtration is the first Step toward production of urine Containing excreted drug. Filtration preserves plasma proteins while removing free drugs and other waste products from the plasma. The large volume of fluid filtered through the glomerulus is an ideal vehicle for drug removal. AS the ultrafiltrate is formed, drugs that are free in the plasma and not bound to plasma proteins or blood cells are filtered. Filtration may be Slower for drugs that are large because of the Size of the pores through which filtration occurs; very large drugs may not be filtered at all. The pores of the glomerulus Contain a fixed negative Charge, So filtration may also be affected by drug Charge. (Patients with poor renal function may have higher levels of drugs secondary to decreased excretion of metabolites. Renal blood flow affects glomerular filtration as well. Less flow=less filtration and less excretion of drugs)