naloxone and Pulpitis

The purpose of this prospective clinical trial was to investigate the analgesic efficacy of three oral medication groups on postoperative endodontic pain in male and female dental patients, with an emphasis on analgesic differences between the sexes. Forty-three patients were administered ibuprofen 600 mg, placebo, or pentazocine 50 mg/0.5 mg naloxone in a randomized, double-blinded manner. Beginning immediately after endodontic treatment, patients took the assigned medication every 6 hours for 24 hours and recorded their degree of discomfort on a 100-mm visual analog scale. Statistical analysis of the data showed that ibuprofen 600 mg provided statistically significantly greater analgesia than placebo at 6 and 12 hours (P = 0.0014 and 0.0024), and pentazocine/naloxone provided statistically significantly greater analgesia than placebo at 12 hours (P = 0.0084). Sex-dependent differences were noted within the pentazocine/naloxone group, which showed significantly greater analgesia in females compared with males (P = 0.007).

Topics: Analgesics, Non-Narcotic; Analgesics, Opioid; Double-Blind Method; Drug Combinations; Female; Humans; Ibuprofen; Likelihood Functions; Linear Models; Male; Naloxone; Pain Measurement; Pain, Postoperative; Pentazocine; Periapical Periodontitis; Prospective Studies; Pulpitis; Root Canal Therapy; Sex Factors; Surveys and Questionnaires; Toothache

A physiological role of substance P (SP) in inflammatory reaction was examined in the rat incisor pulp and inferior lip. SP content in pulps and lips significantly increased after antidromic stimulation of the inferior alveolar nerve. Following the same stimulation, vascular permeability also increased significantly in pulps and lips, and this permeability response was significantly inhibited by an SP-antagonist. Morphine reduced the permeability response to antidromic stimulation in pulps but had no effect in lips. N-methyl levallorphan (a peripherally selective narcotic antagonist) prevented the morphine-induced reduction, and was more potent than naloxone. Morphine caused a marked increase of SP content in pulps following antidromic stimulation of the inferior alveolar nerve but failed in lips. These suggest a possibility that a peripheral SP release-suppressive mechanism by opiates may exist in pulps but not in lips. The permeability response to antidromic stimulation was also reduced by aspirin and a bradykinin antagonist in both of the tissues, indicating that prostaglandin and bradykinin may be related to this response. Since mepyramine and methysergide inhibited the permeability response in lips but were inactive in pulps, there is a difference in participation of histamine and serotonin between the two tissues. SP injection into the dental pulp and lip induced dye leakage. This response was inhibited by compound 48/80 pretreatment in lips whereas it was resistant in pulps. Histamine content in lips decreased significantly after antidromic stimulation and compound 48/80 pretreatment, but it was not changed in pulps. The present results suggest that in lips after being released from the peripheral sensory nerve endings SP may act on vascular system through histamine release from mast cells, while in pulps SP may directly cause vascular response because mast cells may be few or not exist.

Topics: Animals; Capillary Permeability; Cheilitis; Dental Pulp; Evoked Potentials; Histamine Release; Levallorphan; Lip; Morphine; Naloxone; Pulpitis; Rats; Substance P