Side Effects


Typical opioid withdrawal syndrome is expected with naloxone which may be caused by the abrupt withdrawal of opioid in persons physically dependent on them.


Commonly reported adverse events reported with NYXOID® and other naloxone formulations include:1,2

  • Very common (≥ 10%): Nausea
  • Common (≥ 1%, < 10%): Dizziness, headache, tachycardia, hypotension, hypertension, vomiting.


Incomplete reversal

The duration of action of most opioids may exceed that of NYXOID® nasal spray resulting in a return of respiratory and/or CNS depression after an initial improvement in symptoms.


Reversal of respiratory depression by partial agonists or mixed agonist/antagonists such as buprenorphine may be incomplete.1 If an incomplete response occurs, respiration should be mechanically assisted.


Opioid withdrawal

Receiving naloxone can lead to a rapid reversal of the opioid effect which can cause an acute withdrawal syndrome in such patients. Patients who are receiving opioids for the relief of chronic pain may experience pain and opioid withdrawal symptoms when naloxone is administered.1,2


The use of NYXOID® nasal spray in patients who are opioid-dependent may bring about opioid withdrawal characterised by the following signs and symptoms1: body aches, diarrhoea, tachycardia, fever, runny nose, sneezing, piloerection, sweating, yawning, nausea or vomiting, nervousness, restlessness or irritability, shivering or trembling, abdominal cramps, weakness and increased blood pressure.


If these signs and symptoms occur no further NYXOID® should be given.


Reference: 1. NYXOID® nasal spray Product Information, September 2018. 2. McKeage K, Lyseng-Williamson KA. Naloxone nasal spray (Nyxoid) in opioid overdose: a profile of its use in the EU. Drug Ther Perspect 2018;34:150-156.