Polypharmacy, Dosing Trends, and Drug-Drug Interaction Patterns After High-Level Limb Amputation Surgery

Objective The aim of this study was to examine perioperative medication patterns surrounding major amputation surgeries. Design A retrospective chart review of 216 cases of major amputations (transfemoral, hip disarticulation, hemipelvectomy, forequarter) at an academic hospital was conducted, examining medications, dosing changes, and drug-drug interaction warnings preoperatively and postoperatively. Results Medications increased in 76.9% (166/216), remained the same in 10.6% (23/216), and decreased in 12.5% (27/216) of cases. Average number of medications was 7 preoperatively and 10 postoperatively. In 189 cases with preoperative medications present, postoperative dosing remained the same for 74.3%, increased for 9.2%, decreased for 7.6%, and was unknown for 8.9% of medications. Increases in each of type C (monitor therapy), D (consider therapy modification), and X (avoid combination) drug-drug interaction warnings were seen respectively in 59.7%, 62.0%, and 5.1% of cases. Conclusion Polypharmacy is involved preoperatively and increased postoperatively in most cases of major limb amputation, with agent dosing remaining the same or increased in most cases. Drug-drug interaction warnings also increase. These occur at a time of abrupt changes to the body's size, compartments, and physiologic responses. More research and clinical attention are warranted given anticipated changes in pharmacokinetics and pharmacodynamics.

Automated summary

Most major limb amputation cases involve polypharmacy preoperatively and increased medication use or maintenance postoperatively. Drug-drug interaction warnings also increase, indicating the need for further research and clinical attention.