A comparison of the cardiorespiratory effects of ciramadol, dezocine, morphine and pentazocine in the anesthetized dog.
The effects of bolus and infusion of ciramadol, dezocine, morphine and pentazocine were examined in anesthetized dogs. Cardiopulmonary parameters, blood PCO2, PO2 and pH and plasma histamine determinations were made. Ciramadol (2 and 8 mg/kg) did not exhibit any major activity. Dezocine produced slight respiratory depression at 2 mg/kg but no cardiopulmonary effects were observed at this dose. At 8 mg/kg there were also reductions in pulmonary compliance (Cdyn) and resistance (RL), tidal volume (VT) and a marked arterial hypotension. Morphine (2 mg/kg) elicited significant effects on all parameters examined: marked bronchoconstriction, increased arterial PCO2 and pH and corresponding decrease in PO2, slight increase in heart rate and dramatic arterial hypotension. Morphine was the only agent studied to elevate plasma histamine. Histamine (0.015 mg/kg) mimicked the cardiopulmonary actions of morphine but was virtually devoid of effect on blood gases and pH. Pentazocine (8 mg/kg) did not produce bronchoconstriction but did increase VT and reduce respiratory frequency. It produced increases in arterial PCO2 and reductions in pH and PO2. There was a slight bradycardia and hypotension within this dose. These results demonstrate that both ciramadol and dezocine possess less potential than either morphine or pentazocine for producing bronchoconstriction, respiratory depression, hypotension and histamine release.
D000701:Analgesics, Opioid / Q000494:pharmacology*; D000758:Anesthesia; D000818:Animals; D001596:Benzylamines / Q000494:pharmacology; D019086:Bridged Bicyclo Compounds, Heterocyclic; D001952:Bridged-Ring Compounds / Q000494:pharmacology; D003511:Cyclohexanols / Q000494:pharmacology; D003516:Cycloparaffins / Q000494:pharmacology; D003864:Depression, Chemical; D004285:Dogs; D005260:Female; D005740:Gases / Q000097:blood; D006321:Heart / Q000187:drug effects*; D006632:Histamine / Q000097:blood; D008297:Male; D009020:Morphine / Q000494:pharmacology; D010423:Pentazocine / Q000494:pharmacology; D012137:Respiratory System / Q000187:drug effects*; D013764:Tetrahydronaphthalenes
D000701:Analgesics, Opioid; D001596:Benzylamines; D019086:Bridged Bicyclo Compounds, Heterocyclic; D001952:Bridged-Ring Compounds; D003511:Cyclohexanols; D003516:Cycloparaffins; D005740:Gases; D013764:Tetrahydronaphthalenes; D009020:Morphine; D006632:Histamine; C018273:ciramadol; D010423:Pentazocine; C010827:dezocine