Temporal factors in the enhancement of morphine analgesia by desipramine.
Administration of desipramine, the tricyclic noradrenergic agent, for 7 days pre-operatively, had been found to potentiate postoperative morphine analgesia. In this study we investigated the necessary timing of administration of desipramine in its action to potentiate morphine analgesia. We report that the administration of desipramine for only 3 days, starting 7 days before surgery, also potentiated postoperative morphine analgesia and that the analgesia observed was not different from that in patients receiving a full 7 days of desipramine pre-operatively. The potentiation of morphine analgesia observed was most evident as a prolongation of the analgesic response. Patients who also received desipramine for only 3 days, but starting 3 days pre-operatively had an analgesic response to postoperative morphine that was the same as that in patients receiving placebo. The ability of the administration of desipramine early in the pre-operative week to interact with postoperative morphine and the lack of response when desipramine was given late in the week does not have an explanation at present. However, it may reflect the known latency in humans to the onset of the central effects of tricyclic antidepressants (TCAs).
Gordon
Newton C
NC
Department of Medicine, Anatomy and Oral Surgery and Division of Neurosciences, University of California at San Francisco, San Francisco, CA 94143-0452A USA Department of Emergency Medicine, Kaiser Foundation Hospital, Hayward, CAUSA.
Heller
Philip H
PH
Gear
Robert W
RW
Levine
Jon D
JD
D000328:Adult; D003891:Desipramine / Q000627:therapeutic use*; D004311:Double-Blind Method; D004357:Drug Synergism; D005260:Female; D006801:Humans; D008297:Male; D009020:Morphine / Q000627:therapeutic use*; D010147:Pain Measurement; D010149:Postoperative Pain / Q000188:drug therapy* / Q000523:psychology; D013997:Time Factors
D009020:Morphine; D003891:Desipramine