Citation

Bateman DN. Medicine (Abingdon) 2012; 40(3): 141-143.

Copyright

(Copyright © 2012, Medicine Publishing)

DOI

10.1016/j.mpmed.2011.12.028

PMID

unavailable

Abstract

Opioids cause a well-recognized toxidrome including respiratory depression, decreased conscious level, pin point pupils and hypotension. In overdose their toxicity relates to both the amount ingested and speed of absorption. Addicts run into difficulty when a supply changes or adulterants are added, or they have had a period of relative abstinence resulting in loss of tolerance. Some opioids, such as dextropropoxyphene, methadone and tramadol, have additional properties that account for their toxicity. Naloxone is the opioid antagonist of choice and its dose should be titrated according to clinical response. Duration of action is relatively short and repeated doses or infusion may be required. Paradoxical increase in toxicity may be seen if some drug is unabsorbed in the gut before naloxone administration as gut motility recommences.