A review of dosing recommendations for overweight and obese patients.

Abstract

Aim: To evaluate the literature regarding medication dosage recommendations for overweight and obese patients, and to determine if these recommendations are reflected in standard pharmacy reference texts (Australian Medicines Handbook, Drugdex® Micromedex, MIMS, Therapeutic Guidelines and The Royal Children’s Hospital Paediatric Pharmacopoeia).

Method: Relevant literature was identified by extensive database searching, including The Cochrane Library, ACP Journal Club, Evidence Based Medicine, MEDLINE, Embase, CINAHL, BMJ Best Practice, Up-To-Date, as well as numerous clinical practice guideline websites. MESH search terms used were: obesity, overweight, dose response, drug therapy, dosing, and dose. Relevant citations were selected based on title and abstract content. Reference lists of relevant retrievals were also appraised. Any articles relating to antineoplastic agents were excluded.

Results: Thirty articles were retrieved that provided recommendations for dosing of a total of 75 medications or classes of medications in overweight and/or obese patients. Dosing recommendations were found for medications from the following classes: anti-infectives, neuromuscular blockers, benzodiazepines, anaesthetic agents, antihypertensives, methylxanthines, antiepileptics, anticoagulants, opioids. Of these, 29% of the dose recommendations for the medications retrieved were reflected in at least one standard pharmacy reference text.

Conclusion: There is a paucity of high quality information available regarding medication dosing for overweight and obese patients. Of the literature retrieved, many based recommendations for dosing on small, single centre studies or expert opinion. Several references provided conflicting recommendations for the same medication. Often no recommendation was provided in the standard pharmacy reference text with regards to dosing in overweight or obese patients. In the cases where a recommendation was made, this was frequently different to those recommendations found in the literature. Further research is needed to guide clinicians in regards to dosing of medications for overweight and obese patients.