Muscle Relaxants and Renal Failure

Abstract

Of all the drugs used in anesthesia, muscle relaxants are among the most affected by renal failure. The uremic state is associated with a variety of derangements which predispose for adverse drug reactions. These include: decreased renal excretion of drugs and their metabolites, decreased renal metabolism, altered pharmacokinetics including bioavailability, volumes of distribution (V D ), changes in protein binding, lipid solubility, total body weight, altered pharmacodynamics, hepatic metabolism, and altered elimination. In addition, there may be changes in end organ response [1]. Acidosis affects the action of some drugs and is the result of metabolism of others. Antacids decrease the absorption of many drugs. Bennett et al. [2] compiled an extensive list of guidelines for the prescription of drugs in renal failure. Dosage assessments for renal failure and the effects of dialysis upon each drug are listed as well as toxicity and adverse systemic side effects. In general, the loading dose of a drug in renal failure is similar to that for a patient without end-stage renal disease (ESRD).