John Neubert1, Joyson J. Karakunnel2, Jaime Brahim3, Raymond A. Dionne4*
1Department of Orthodontics, College of Dentistry, University of Florida, Florida, USA
2Med Immune, School of Medicine, University of Maryland, USA
3Department of Oral Surgery, School of Dentistry, University of Maryland, USA
*4Department of Pharmacology, Brody School of Medicine, East Carolina University, USA
*Corresponding author: Raymond A. Dionne, Department of Pharmacology, Brody School of Medicine, Department of Foundational Sciences, School of Dental Medicine, East Carolina University, 6S19 Brody Medical Sciences Building, 600 Moye Boulevard, Greenville NC 27834-4354, USA, Tel: +1 2527442108; Fax: +1 2527443203; E-mail: email@example.com
Received date: 2 March, 2017; Accepted date: 4 April, 2017; Published date: 10 April, 2017
Capsaicin, a member of the vanilloid class, binds to the Transient Receptor Potential Channel-Vanilloid Subtype 1 (TRPV-1), a Ligand-Gated Calcium Ionophore commonly known as VR-1 producing a selective activation followed by ablation of pain specific neurons. The analgesic potential of local administration of capsaicin as a prototype of the vanilloid class was evaluated post-operatively in the oral surgery model of acute pain. Subjects in this double-blinded, placebo and positive controlled trial randomly received placebo or capsaicin 24 hours prior to oral surgery and ketorolac or placebo immediately prior to surgery. The dose of capsaicin was chosen to minimize discomfort following the injection (24 hours prior to tooth removal) that might permit patients to identify which treatment group they had been assigned to. One impacted third molar was removed and patients rated their pain every 20 minutes for a total of 240 minutes and then at home at 12, 24, and 48 hours using a 100 mm VAS. The capsaicin group reported significantly less pain compared to the placebo group at the 60, 80 and 100-minute observations after surgery. There was no significant difference between groups at the 12, 24, and 48-hour observations post-operatively. Rescue medication usage was similar among all three groups. There were a greater percentage of patients without side effects in the capsaicin group.
These data indicate that 100µg capsaicin demonstrates  analgesic activity in a clinical model predictive of analgesia for vanilloid receptor ablation in humans. The relatively short duration of analgesia may be due to incomplete receptor inactivation due to dose-limiting discomfort initially produced by sub-mucosal administration of capsaicin and the contribution of other nociceptive fibers over time not containing TRPV1 receptors.