Drug Use in Patients with Renal Failure

In general, dosage adjustment in RF is not required when (a) renal elimination of the drug is 50 mL/min, and for most antibiotics, when GFR is still > 20 mL/min. For drugs with narrow margin of safety and the main elimination is by renal excretion (e.g. aminoglycosides, vancomycin, digoxin), dosage adjustment is required in all degrees of RF. Drug dosage in RF can be estimated from calculation or dosing tables. Drug use in RF should be avoided if too risky (eg. tetracycline) and other safer drugs are available. The dosage estimation should be refi ned by titration of effi cacy and safety in individual patients. Supplemental dose postHD is required when HD clearance is at least 30% of total body clearance. Predictably, this is for drugs with MW < 500 D, water soluble, uncharged, minimal protein binding, and V d < 1 L/kg. Alteration in pharmacokinetics and pharmacodynamics of drugs in RF causes increased risk of adverse drug reactions. Multiple medications in patients with RF cause increased drug interactions in these patients.