Naloksonin

Naloksonin is an opioid receptor antagonist used to reverse acute opioid toxicity. In many languages, the term naloksonin refers to the drug more widely known in English as naloxone. It works by competitively binding to mu-opioid receptors, blocking opioids from producing their depressant effects on respiration and consciousness.

Naloksonin is indicated for suspected opioid overdose presenting with life-threatening respiratory depression or diminished levels of consciousness. It is administered by emergency responders, clinicians, and in some places by trained laypersons. The reversal of opioid effects is usually rapid, but the duration of naloksonin’s action is shorter than that of many opioids, so respiratory depression can recur as the drug wears off. Patients must be monitored and additional doses may be required.

Pharmacokinetically, naloksonin is poorly absorbed orally, so it is given parenterally or intranasally. Common routes include intravenous, intramuscular, and intranasal administration. Onset is typically minutes, with intravenous effects seen within 1–2 minutes and intranasal onset within several minutes; duration of action ranges from about 30 to 120 minutes, depending on factors such as dose and the specific opioid involved. Metabolism occurs in the liver, and excretion is primarily via urine.

Common safety considerations include the potential for withdrawal symptoms in opioid-dependent individuals, including agitation, nausea, vomiting, sweating, and an increased heart rate or blood pressure. Serious adverse reactions are rare but may occur, particularly in patients with cardiovascular disease or hypersensitivity. Naloksonin is generally used under medical supervision, with ongoing monitoring for signs of recurrent overdose and the need for re-dosing.

Naloksonin is available in various formulations, including injectable preparations and nasal sprays, and is included in many opioid overdose response programs worldwide.