Indications
Naloxone Hydrochloride is an emergency medicine used to reverse the effects of opioid drugs, such as Morphine, Pethidine, Fentanyl, Tramadol, Methadone and Heroin. It is used for suspected opioid overdose, when breathing becomes slow or stops, and to reverse breathing depression caused by opioids given during surgery or labour, including in newborn babies whose mothers received opioids.
How It Works
Naloxone is an opioid antagonist (blocker). It attaches to the same receptors in the brain and spinal cord that opioids use, pushes the opioid off them and blocks its action. This quickly restores breathing and consciousness. It has little effect in a person who has not taken an opioid.
Dosage and Administration
Naloxone injection is given by a doctor, nurse or trained responder into a vein, muscle or under the skin. The dose is set by the doctor and may be repeated every few minutes until breathing improves. Because many opioids last longer than Naloxone, the person must be watched closely and may need further doses. Doses for newborns and children are worked out by the doctor.
Interactions
- Opioid painkillers and cough medicines: Naloxone blocks their effect, including pain relief.
- Buprenorphine: its effect is only partly reversed and higher doses may be needed.
- In people dependent on opioids, Naloxone can trigger sudden withdrawal symptoms.
Contraindications
Not used in people with known allergy to Naloxone. There are few other absolute restrictions in a life-threatening overdose; the doctor will weigh the risks.
Side Effects
In people who regularly use opioids, sudden withdrawal may cause restlessness, agitation, sweating, yawning, runny nose, goose bumps, nausea, vomiting, stomach cramps, diarrhoea, shivering and fast heartbeat. Pain may return quickly after surgery. Rarely, high blood pressure, irregular heartbeat, fits or fluid in the lungs may occur.
Get urgent medical help if, after Naloxone, breathing slows again, the person becomes drowsy again, or there is chest pain, a fit, or severe breathlessness. Always call for emergency help in a suspected overdose, even if the person wakes up.
Pregnancy and Lactation
Naloxone may be used in pregnancy when needed to save life. In a mother who is dependent on opioids it may cause withdrawal in both mother and baby, so the doctor uses it carefully. It is unlikely to harm a breastfed baby when given as a short treatment.
Precautions and Warnings
- The person must stay under medical observation, because the opioid may outlast Naloxone and symptoms can come back.
- Used with care in people with heart disease or those who have received heart-affecting medicines.
- In newborns of opioid-dependent mothers, sudden withdrawal can be dangerous.
- Naloxone does not reverse overdose of non-opioid drugs such as alcohol or sleeping tablets of the benzodiazepine type.
Overdose
Naloxone itself has a wide safety margin. Too much in an opioid-dependent person mainly causes severe withdrawal symptoms, which are treated in hospital.
Therapeutic Class
Opioid antagonist (antidote).
Storage
Store below 30°C, away from light, as directed on the pack. Do not freeze. Keep out of the reach of children.
Prepared by the Oshud Alo team from standard drug references. For information only; always follow your doctor's advice.