Evaluation of transdermal fentanyl patches for analgesia in cats undergoing onychectomy

• Published in: Journal of the American Veterinary Medical Association Vol. 217; no. 7; p. 1013
• Main Authors: Franks, J N, Boothe, H W, Taylor, L, Geller, S, Carroll, G L, Cracas, V, Boothe, D M
• Format: Journal Article
• Language: English
• Published: United States 01.10.2000
• Subjects: Administration, Cutaneous; Analgesia - economics; Analgesia - veterinary; Animals; Body Temperature - drug effects; Butorphanol - blood; Butorphanol - therapeutic use; Cats - surgery; Fentanyl - administration & dosage; Fentanyl - blood; Fentanyl - therapeutic use; Hoof and Claw - surgery; Postoperative Complications - drug therapy; Postoperative Complications - etiology; Postoperative Complications - veterinary; Tendons - surgery
• ISSN: 0003-1488; 1943-569X
• DOI: 10.2460/javma.2000.217.1013

To evaluate efficacy and safety of using transdermal fentanyl patches (TFP) for analgesia in cats undergoing onychectomy. Randomized controlled clinical trial. 45 client-owned cats weighing > or = 2.7 kg (5.9 lb) undergoing onychectomy, onychectomy and ovariohysterectomy, or onychectomy and castration. Cats were randomly assigned to be treated with a TFP (25 micrograms/h) or butorphanol; TFP were applied a minimum of 4 hours before surgery (approx 8 hours prior to extubation). Rectal temperature, heart rate, respiratory rate, force applied by the forelimbs, and serum fentanyl concentration were measured, and temperament, recovery, degree of sedation, severity of pain, severity of lameness, and appetite were scored before and periodically for up to 40 hours after surgery. Cats treated with a TFP had better recovery scores at 2 of 4 evaluation times, lower sedation scores at 2 of 8 evaluation times, and lower pain scores at 6 of 8 evaluation times, compared with cats treated with butorphanol. Use of a pressure-sensitive mat to evaluate force applied by the forelimbs did not reveal any differences between groups but did reveal a significant difference between preoperative and postoperative values. Mean +/- SD serum fentanyl concentrations were 1.56 +/- 1.08, 4.85 +/- 2.38, 4.87 +/- 1.56, and 4.35 +/- 2.97 ng/ml approximately 8, 24, 32, and 48 hours, respectively, after TFP placement. Results suggest that use of a TFP (25 micrograms/h) for postoperative analgesia in cats undergoing onychectomy with or without surgical sterilization is safe and effective.