Evaluation of dosage adjustment in patients with renal impairment

Intern Med J. Jan-Feb 2003;33(1-2):10-3. doi: 10.1046/j.1445-5994.2003.00330.x.

Abstract

Aims: To determine whether appropriate dosage adjustments are made in patients with significant renal impairment for drugs with a high fractional renal clearance.

Methods: Evaluation of dosage adjustment was performed in patients who were admitted to a 480-bed metropolitan hospital (Princess Alexandra Hospital, Brisbane, Australia) with an estimated creatinine clearance of < or =40 mL/min. All drugs had a high fractional renal excretion. A prescribed dose within 30% of the calculated dose was considered appropriate.

Results: Doses were found to be inappropriately high in 111 (44.8%) of 248 admission prescriptions of the targeted drugs. Doses were appropriately reduced in hospital in 26 patients (23.4%). Seventy-three (29.3%) prescriptions were continued with excessive doses. Only 34 prescriptions for the target drugs were initiated in hospital, of which 88.2% were appropriately dosed.

Conclusions: A significant percentage of patients with renal impairment are admitted to hospital on inappropriately high doses of drugs, with a high fractional renal excretion and low therapeutic index. Doses are appropriately reduced in hospital in some patients but there is still room for improvement [corrected].

MeSH terms

  • Administration, Oral
  • Adrenergic beta-Antagonists / administration & dosage
  • Adult
  • Aged
  • Aged, 80 and over
  • Angiotensin-Converting Enzyme Inhibitors / administration & dosage
  • Dose-Response Relationship, Drug
  • Female
  • Humans
  • Hypoglycemic Agents / administration & dosage*
  • Male
  • Medical Audit
  • Medication Errors / statistics & numerical data*
  • Metabolic Clearance Rate
  • Metformin / administration & dosage*
  • Metformin / pharmacokinetics
  • Middle Aged
  • Pharmaceutical Preparations / administration & dosage*
  • Practice Patterns, Physicians' / standards
  • Renal Insufficiency / metabolism*

Substances

  • Adrenergic beta-Antagonists
  • Angiotensin-Converting Enzyme Inhibitors
  • Hypoglycemic Agents
  • Pharmaceutical Preparations
  • Metformin