title: Dental impaction pain model as a potential tool to evaluate drugs with efficacy in neuropathic pain.
abstract: Intravenous lidocaine, a nonspecific Na-channel blocker, was used to assess the dental impaction model for evaluation of neuropathic pain drugs. Sixty patients, experiencing moderate or severe pain after removal of > or = 2 third molars, were randomized (2:2:1:1) to lidocaine (4 mg/kg; maximal dose 300 mg), oxycodone/acetaminophen (10/650 mg), placebo, and active placebo (diphenhydramine, 50 mg). Lidocaine provided a modest degree of pain relief. Predefined endpoints of total pain relief and sum of pain intensity at 2, 4, and 6 hours showed numerically, not statistically significantly, greater pain relief versus placebo. A significantly greater effect over placebo was observed in peak effect and at shorter time points (30 minutes and 1 hour), consistent with the pharmacokinetic profile (plasma concentration of approximately 2 mug/mL). Oxycodone/acetaminophen provided significantly greater analgesia versus placebo, validating study conduct, and significantly greater pain relief was observed versus lidocaine, which is consistent with a smaller portion of dental extraction pain being of neuropathic origin.
authors.affiliation: Department of Clinical Immunology & Analgesia, Merck Research Laboratories, Rahway, New Jersey, USA.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Malmstrom
authors.forename: Paul
authors.initials: P
authors.lastname: Kotey
authors.forename: Megan
authors.initials: M
authors.lastname: McGratty
authors.forename: Rohini
authors.initials: R
authors.lastname: Ramakrishnan
authors.forename: Keith
authors.initials: K
authors.lastname: Gottesdiener
authors.forename: Alise
authors.initials: A
authors.lastname: Reicin
authors.forename: John A
authors.initials: JA
authors.lastname: Wagner
mesh_terms: D000082:Acetaminophen / Q000627:therapeutic use; D000293:Adolescent; D000328:Adult; D018712:Analgesics, Non-Narcotic / Q000627:therapeutic use*; D000701:Analgesics, Opioid / Q000627:therapeutic use*; D000779:Anesthetics, Local / Q000097:blood / Q000493:pharmacokinetics / Q000627:therapeutic use*; D004311:Double-Blind Method; D004338:Drug Combinations; D005260:Female; D006801:Humans; D008012:Lidocaine / Q000097:blood / Q000493:pharmacokinetics / Q000627:therapeutic use; D008297:Male; D009437:Neuralgia / Q000188:drug therapy* / Q000209:etiology; D010098:Oxycodone / Q000627:therapeutic use; D010147:Pain Measurement; D010149:Postoperative Pain / Q000188:drug therapy* / Q000209:etiology; D010523:Peripheral Nervous System Diseases / Q000150:complications; D010865:Pilot Projects; D014081:Tooth Extraction / Q000009:adverse effects*
chemical_list: D018712:Analgesics, Non-Narcotic; D000701:Analgesics, Opioid; D000779:Anesthetics, Local; D004338:Drug Combinations; D000082:Acetaminophen; D008012:Lidocaine; D010098:Oxycodone