OBJECTIVE

This analysis compared opioid-related adverse events (ORADEs) observed with fentanyl iontophoretic transdermal system (ITS) versus morphine intravenous (iv.) patient-controlled analgesia (PCA) in the management of postoperative pain.

METHODS

Safety data from four Phase IIIB randomized, active-comparator trials were pooled for this analysis (n = 1288 fentanyl ITS and 1313 morphine iv. PCA patients). Treatment-emergent adverse events were collected via spontaneous report. In this post hoc analysis, ORADEs were defined as apnea, confusion, constipation, dyspnea, hypotension, hypoventilation, hypoxia, ileus, nausea, pruritus, somnolence, tachycardia, urinary retention and vomiting. Odds ratios (OR) and 95% CI were calculated for all ORADEs and p-values were based on logistic regression with treatment as effect.

RESULTS

There were fewer patients in the fentanyl ITS group compared with the morphine iv. PCA group who experienced at least one ORADE (52.7 vs 59.1%, respectively; OR: 0.772: 95% CI: 0.661-0.901; p = 0.0011). The ORADEs that occurred less frequently in the fentanyl ITS group than in the morphine iv. PCA group included hypotension (3.7 vs 5.5%, respectively; OR: 0.667; 95% CI: 0.459-0.969; p = 0.0338), hypoventilation (0.9 vs 1.9%, respectively; OR: 0.444; 95% CI: 0.217-0.906; p = 0.0256), nausea (40.3 vs 44.5%, respectively; OR: 0.842; 95% CI: 0.721-0.984; p = 0.0310), pruritus (5.5 vs 9.4%, respectively; OR: 0.559; 95% CI: 0.413-0.757; p = 0.0002) and tachycardia (1.6 vs 2.8%, respectively; OR: 0.489; 95% CI: 0.277-0.863; p = 0.0136). No ORADEs occurred more frequently in the fentanyl ITS group compared with the morphine iv. PCA group.

CONCLUSIONS

Fentanyl ITS, in the management of acute postoperative pain, offered safety advantages in terms of ORADEs compared with morphine iv. PCA.