Renal excretion of cimetidine.

摘要: The renal excretion and certain pharmacokinetic properties of cimetidine were studied in anesthetized rats undergoing moderate osmotic diuresis. When concentrations plasma (Pcim) low, ca. 2 micrograms/ml, the clearance (Ccim) was 2.64-fold greater than glomerular filtration rate (GFR). Ccim lower at higher concentrations, e.g., 200 Ccim/GFR 1.24. animals with low Pcim alkalotic (bicarbonate infusion), 1.82 (different from control, P less 0.01). In nonalkalotic animals, not influenced by changes urine flow rate. High levels completely blocked net secretion cation, tetraethylammonium ion, but did inhibit anion p-aminohippurate. half-time 43 to 49 min. apparent volume distribution 3.6-fold estimated total body water. We conclude that is secreted organic cation transport mechanism it probably undergoes passive reabsorption (nonionic diffusion) a modest extent when alkaline. relatively long half-life drug body, despite its very high clearance, attributable large distribution.