Prolonged post-operative hydrocodone usage due to psychotropic drug interaction

Objectives: To explore pain outcomes in patients prescribed hydrocodone and psychotropic medications with or without CYP2D6 inhibition activity.

Methods: Patients hospitalized for lower/limited upper extremity injuries who were prescribed hydrocodone alongside a psychotropic medication were considered for this study (n=224). A subset of these patients (n=178) was prescribed a psychotropic medication known to inhibit CYP2D6, while the remainder (n=46) were prescribed psychotropic medications without CYP2D6 inhibition activity. Patient demographics and pain outcomes were collected by electronic health record review and interviews.

Results: Patients taking a psychotropic inhibitor of CYP2D6 exhibited longer duration of opioid use post-discharge (median 33 days [IQR 10-99]) compared with patients taking a psychotropic non-inhibitor (4 days [2-20], p<0.001). No significant differences were observed with in-hospital pain outcomes, including total dose of hydrocodone administered, duration of hydrocodone use, pain index scores, and the occurrence of common mild/moderate/severe hydrocodone side effects.

Conclusions: Patients prescribed at least one psychotropic inhibitor of CYP2D6 were more likely to continue using hydrocodone for up to 3 months following surgery. Knowledge of these critical drug-drug interactions could enhance clinical practice and improve patient outcomes. This study highlights negative post-operative pain outcomes in patients prescribed hydrocodone alongside a psychotropic inhibitor of CYP2D6. The results of this study indicate that patients taking psychotropic medications that inhibit CYP2D6 are at increased risk for prolonged hydrocodone use following orthopedic surgery.