Oral herpes simplex reactivation after intrathecal morphine: a prospective randomized trial in an obstetric...

There is now evidence for an association between the use of epidural morphine and reactivation of herpes simplex labialis (HSL). There are no studies that definitively demonstrate the relationship between HSL reactivation and spinal intrathecal morphine. To investigate this relationship, we randomized and prospectively studied 100 obstetric patients with a history of HSL undergoing cesarean delivery under spinal anesthesia. One group received intrathecal morphine plus IV morphine via patient-controlled analgesia (ITM+PCA group) for postoperative analgesia, and a second group received only IV morphine via patient-controlled analgesia for postoperative analgesia (PCA-only group). Patients were followed for a 30-day period. In the ITM+PCA group 19 (38%) patients had HSL reactivation whereas eight (16.6%) had HSL reactivation in the morphine PCA-only group (P = 0.028). The incidence of pruritus in the ITM+PCA group was also more frequent in the early postoperative period. Our data show HSL reactivation in both the ITM+PCA group and PCA-only morphine group, with a more frequent incidence in the ITM+PCA group.