Duloxetine to Prevent Chronic Postsurgical Pain After Inguinal Hernia Repair in Patients at High Risk

The clinical trial will be conducted in 14 Spanish hospitals. It is estimated, based on our previous studies, that 2855 patients scheduled for elective inguinal hernia surgery will have to be assessed to detect patients with ≥ 27% level of risk for Chronic Post-Surgical Pain (CPSP). These high-risk patients will be randomized to 2 treatment groups: one will receive duloxetine for 2 weeks prior to surgery and 1 week after surgery (intervention group) and the other the placebo (control group) during the same periods. The primary outcome will be a ≥ 50% decrease in the CPSP incidence in the intervention group compared to the placebo group, 4 months after surgery.

Prospective, multicenter, double-blind randomized double-blind controlled trial. In the first phase the investigators use the Chronic Post-Surgical Pain (CPSP) risk model to select patients scheduled for inguinal hernia repair with a ≥27% level of risk for CPSP. A total of 2855 patients will be screened in 14 Spanish hospitals (Hospital del Mar (Barcelona) / Hospital Germans Trias i Pujol (Badalona) / H Vall d'Hebrón (Barcelona) / Hospital de Bellvitge (Barcelona) / Hospital de Cruces (Bilbao) / Hospital 12 de Octubre (Madrid) / Hospital de Valme (Sevilla) / Hospital de Son Espases (Palma de Mallorca) / Hospital Son Llatzer (Palma de Mallorca) / Hospital General de Valladolid (Valladolid)/ Hospital General de Alicante (Alicante)/ Hospital Lluís Alcanyís de Xativa). The high-risk patients will be randomized to 2 treatment groups to receive 30 mg/d of duloxetine for 2 weeks prior to surgery and 1 week after surgery (intervention group) or placebo (control group) during the same periods. The primary outcome will be a decrease in the CPSP incidence at 4 months in the intervention group compared to the placebo group with an odds ratio of 0.44 as the effect size. The investigators estimate that it will be necessary to treat 294 participants (147 in each group). Participants that might have CPSP will be detected in follow-up telephone interviews approximately 3 months after surgery. Participants who report pain at that time will be scheduled for an appointment at their hospital's pain clinic to confirm the CPSP diagnosis by exhaustive physical examination and to assess pain intensity, characteristics, and degree of interference with daily living.