Severe hypertension induced by naloxone

Am J Med Sci. 1985 Aug;290(2):70-2. doi: 10.1097/00000441-198508000-00005.


To evaluate the role of endogenous opioid peptides in regulating the blood pressure of hypertensive individuals, we administered the opiate antagonist, naloxone. One individual developed a severe hypertensive response, mean arterial pressure rising from a baseline of 107 mmHg to 147 mmHg 145 min after naloxone injection and infusion. After stopping naloxone, his blood pressure rapidly returned to baseline. Re-challenge with naloxone and clonidine resulted in a modest reduction of blood pressure in contrast to the profound hypotension induced by clonidine alone during a third session. Thus, endogenous opioids appear to regulate blood pressure in some hypertensive patients and opiate antagonists must be administered with caution to these individuals.

Publication types

  • Case Reports
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Blood Pressure / drug effects
  • Clonidine / pharmacology
  • Endorphins / blood
  • Humans
  • Hypertension / blood
  • Hypertension / chemically induced*
  • Male
  • Middle Aged
  • Naloxone / adverse effects*
  • Naloxone / pharmacology
  • beta-Endorphin


  • Endorphins
  • Naloxone
  • beta-Endorphin
  • Clonidine