Drugs and the kidney

The kidneys play a very important part in the control of drug therapy particularly with regard to excretion and metabolism. By virtue of their rich blood supply and their unique concentrating powers they are exposed to high levels of drugs and are therefore potentially vulnerable to damage. Furthermore, in states of diminished renal function they are unable to excrete certain drugs and their metabolites at an adequate rate to keep blood concentrations below the limits of toxicity. Careful attention must therefore be paid to dosage regimens particularly with drugs that are therapeutically necessary and toxic agents should be avoided when a less toxic alternative can be used. Measurement of blood levels should be performed when possible so as to avoid overdosage. Further modification of dosages may be necessary with toxic drugs and when patients are on dialysis programmes.