CarbacholAnalgesiaAnalgesia, EpiduralAnalgesia, ObstetricalAnalgesia, Patient-ControlledAnalgesics, OpioidPain, PostoperativeCholinergic AgonistsMorphinePain MeasurementBupivacaineAnesthetics, LocalAcupuncture AnalgesiaFentanylReceptors, MuscarinicAnalgesicsAnesthesia, EpiduralMuscarinic AgonistsMeperidineLabor PainSufentanilPainInjections, SpinalNerve BlockLabor, ObstetricAtropineAnesthesia, ObstetricalParasympathomimeticsAmidesMuscarinic AntagonistsAnesthesia, SpinalTramadolMuscle, SmoothAnalgesics, Non-NarcoticDouble-Blind MethodReceptor, Muscarinic M3Dose-Response Relationship, DrugNaloxoneCesarean SectionPostoperative Nausea and VomitingPain ThresholdInterpleural AnalgesiaQuinuclidinyl BenzilateGuinea PigsClonidineDrug ToleranceReceptors, Opioid, muMuscle ContractionAnesthesia, GeneralConscious SedationKetorolacLabor Stage, FirstReceptor, Muscarinic M2HydromorphoneLidocaineCalciumPain ManagementAnesthesia, CaudalPirenzepineN-MethylscopolamineAnesthesia and AnalgesiaKetamineFemoral NervePiperidinesPregnancyParasympatholyticsTracheaReceptors, OpioidPirinitramideHypnotics and SedativesRats, Sprague-DawleyNeostigmineButorphanolAlfentanilIleumNalbuphineAcetylcholineNarcotic AntagonistsAnesthetics, CombinedCholinergic AgentsAnesthesia, ConductionThoracotomyOpioid PeptidesHistamineElectroacupunctureMepivacainePruritusKetoprofenParotid GlandAdjuvants, AnesthesiaPlacebo EffectReceptor, Muscarinic M1Morphine DerivativesHyperalgesiaInositol PhosphatesTime FactorsProspective StudiesPhosphatidylinositolsAnesthesia, LocalPeriaqueductal Gray