Excellent review of opioid toxicity
July 10, 2012, 9:48 pm
Management of Opioid Analgesic Overdose. Boyer EW. N Engl J Med 2012 Jul 12;367:146-55.
No abstract available online
This is an excellent review of issues involved in managing opioid overdose, that has the distinct advantage of offering strong opinions on some controversial topics. While I’m not sure that I agree with everything Dr. Boyer advocates in this article, I appreciate an author who takes positions and says what he thinks. (This is more rare than you might imagine.)
Some of the important points made in this review:
- Since patients with opioid overdoses are at risk for compartment syndrome, the clinician should palpate all major muscle groups looking for firmness, swelling or tenderness.
- The initial dose of naloxone should be small (0.04 mg in adults), followed every 2-3 minutes with escalating doses of 0.5 mg, 2.0 mg, 4 mg, 10 mg, and 15 mg until there is adequate response. Lack of response after the 15 mg dose suggests that opioid overdose is not the cause of respiratory or CNS depression.
- The pharmacokinetics of opioid medications may be altered in pediatric and geriatric patients, who must be observed carefully.
- Aside from children and the elderly, patients whose respiratory rate improves after administration of naloxone should be observed for 4 to 6 hours before discharge is considered.
Dr. Boyer points out the following pitfalls in managing opioid overdose:
- failure to appreciate that naloxone will prevent recurrence of opioid toxicity
- failure to recognize that response to a low dose of naloxone does not necessarily indicate mild toxicity
- failure to recognize concomitant acetaminophen toxicity in a patient with opioid overdose who may have ingested a combination product
- failure to appreciate that children and the elderly may have prolonged or recurrent toxicity because of altered metabolism
There are some statements in this article to which I take exception. For example, Dr. Boyer states that: “Naloxone can be administered without compunction in any patients, including patients with opioid dependence.” Maybe it’s just me, butI still would have some compunction, having seen too many cases in which precipitation of acute withdrawal turned quite unpleasant — although starting at the ultralow dose recommended in this review would probably minimize these reactions. In addition, I am not sure that Dr. Boyer is on firm ground when he states that naloxone absolutely does not cause pulmonary edema. This issue is still controversial. Unfortunately, there is no discussion of nebulized naloxone. And, finally, there is no mention of what I believe is a frequent pitfall in management: unnecessarily administering naloxone to a patient who might be slightly drowsy, but is not having respiratory depression or airway compromise.
Nonetheless, a review well worth reading. Recommended.