Evaluation of dosage adjustment in patients with renal impairment.
OBJECTIVE
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].
Pillans
P I
PI
Department of Clinical Pharmacology, Princess Alexandra Hospital, Brisbane, Queensland, Australia. peter_pillans@health.qld.gov.au
Landsberg
P G
PG
Fleming
A M
AM
Fanning
M
M
Sturtevant
J M
JM
D000284:Administration, Oral; D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000008:administration & dosage; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D007004:Hypoglycemic Agents / Q000008:administration & dosage*; D008297:Male; D008485:Medical Audit; D008508:Medication Errors / Q000706:statistics & numerical data*; D008657:Metabolic Clearance Rate; D008687:Metformin / Q000008:administration & dosage* / Q000493:pharmacokinetics; D008875:Middle Aged; D004364:Pharmaceutical Preparations / Q000008:administration & dosage*; D010818:Practice Patterns, Physicians' / Q000592:standards; D051437:Renal Insufficiency / Q000378:metabolism*
D000319:Adrenergic beta-Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D007004:Hypoglycemic Agents; D004364:Pharmaceutical Preparations; D008687:Metformin