[Individualization of drug therapy in renal or liver insufficiency]

Individualisation of drug dosage in patients with renal or hepatic failure may prevent excessive drug accumulation and thus potentially reduce adverse drug reactions and costs. In renal failure, renal function may be estimated by combined evaluation of serum creatinine values and patient characteristics. Then individual elimination capacity of a given drug in the individual patient may be calculated and dosage accordingly adjusted. In severe liver cirrhosis, after peroral administration of drugs with a high extraction ratio each single dose has to be reduced because of increased bioavailability and decreased clearance. After i.v. administration and dosing of drugs with a low extraction ratio maintenance dose should be reduced either by prolonging the dosing interval or by decreasing each single dose.