Naloxone for the Reversal of Opioid Adverse Effects

Marcia L. Buck, PharmD, FCCP


Pediatr Pharm. 2002;8(8) 

In This Article

Adverse Effects

As described earlier, naloxone produces little clinically significant pharmacologic effect in the absence of endogenous or exogenous opioids, so there are few adverse effects associated with its use. The abrupt reversal of an opioid by naloxone may produce symptoms of acute withdrawal such as agitation, nausea and vomiting, diarrhea, diaphoresis, tachycardia, hypertension, shivering, yawning, tremors, or seizures in patients with physiologic dependence, including neonates whose mothers were chronic opioid users. In postoperative patients, particularly those with underlying cardiac disease, the administration of naloxone has been associated with changes in blood pressure, ventricular tachycardia or fibrillation, asystole, and pulmonary edema. The mechanism for these reactions may be an increase in sympathetic tone induced directly by naloxone or mediated indirectly through hypercapnia.[10,26]

While most patients tolerate naloxone without incident, the potential for long-term adverse effects on neurologic development in infancy is not known. There is concern that administration at the time of delivery may adversely affect the release of endorphins and response to opioids in neonates.[12] In a study of young rats, administration of naloxone over a 15 day period produced hyperalgesia and a blunted response to morphine lasting up to three months.[27]


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.