title: Potentiation of narcotic-induced antinociception by tripelennamine in morphine-tolerant and drug-naive mice.
abstract: The ability of tripelennamine and chlorpheniramine to potentiate morphine- and pentazocine-induced antinociception in drug-naive and morphine-tolerant mice was tested utilizing the hot-plate method. Both tripelennamine and chlorpheniramine alone produced dose-dependent increases in hot plate latency which were naloxone reversible. Cross-tolerance developed between tripelennamine and morphine, whereas no cross-tolerance developed between chlorpheniramine and morphine. Neither tripelennamine nor chlorpheniramine significantly potentiated morphine-induced antinociception in drug-naive mice. The effects of tripelennamine and morphine were additive. Tripelennamine but not chlorpheniramine, however, significantly potentiated antinociception produced by low but not high doses of pentazocine in drug-naive mice. Furthermore, in morphine-tolerant mice, tripelennamine, but not chlorpheniramine, potentiated both morphine- and pentazocine-induced antinociception. It is concluded that the abuse of various narcotic-tripelennamine combinations can be attributed, at least in part, to a specific property of tripelennamine to potentiate narcotic effects in the drug-naive and morphine-tolerant state.
mesh_terms: D000698:Analgesia; D000818:Animals; D002744:Chlorpheniramine / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004361:Drug Tolerance; D008297:Male; D051379:Mice; D009020:Morphine / Q000494:pharmacology*; D009270:Naloxone / Q000494:pharmacology; D010423:Pentazocine / Q000494:pharmacology; D014309:Tripelennamine / Q000494:pharmacology*
chemical_list: D009270:Naloxone; D014309:Tripelennamine; D002744:Chlorpheniramine; D009020:Morphine; D010423:Pentazocine