Nalbufin

Indications

Nalbuphine Hydrochloride is an opioid painkiller given by injection. It is used to relieve moderate to severe pain, for example after surgery or injury, as pain relief before and during operations, as an addition to anaesthesia, and sometimes for pain during labour.

How It Works

Nalbuphine acts on opioid receptors in the brain and spinal cord in a mixed way: it switches on kappa receptors, which reduces pain, and partly blocks mu receptors. Because of this, its effect on breathing reaches a ceiling, so higher doses do not keep slowing breathing as much as pure opioids such as Morphine. It also causes sedation.

Dosage and Administration

Nalbuphine injection is given by a doctor or nurse into a vein, muscle or under the skin. The dose is decided for each patient based on the pain, body weight and medical condition, and may be repeated at set intervals with a maximum daily limit. Doses for anaesthesia and for children are set by the specialist. Patients are monitored for breathing and sedation after each dose.

Interactions

• Benzodiazepines (such as Diazepam or Midazolam), sleeping pills, other opioids, general anaesthetics, Gabapentin, Pregabalin, sedating antihistamines and alcohol add to sedation and can slow breathing dangerously.
• In people who regularly use opioids such as Morphine, Methadone or Heroin, Nalbuphine can cause withdrawal symptoms and may reduce the pain-relieving effect of those opioids.
• MAO inhibitors and serotonergic medicines should be used with caution.

Contraindications

• Allergy to Nalbuphine.
• Severe breathing depression or acute severe asthma without monitoring and resuscitation equipment.
• Known or suspected blockage of the stomach or bowel, including paralytic ileus.

Side Effects

The most common side effect is sleepiness. Others include sweating, clamminess, nausea, vomiting, dizziness, vertigo, dry mouth and headache. Pain or irritation can occur at the injection site.

Less common effects include slowed breathing, low or high blood pressure, slow or fast heartbeat, confusion, nervousness, unusual dreams, blurred vision and allergic reactions. Long-term use can lead to dependence.

Get urgent medical help, or alert the nurse straight away, if breathing becomes slow or shallow, the person is very hard to wake, lips turn blue, or there is fainting, a severe rash, or swelling of the face and throat.

Pregnancy and Lactation

Nalbuphine should be used in pregnancy only if clearly needed. When given during labour it can cause a slow heartbeat in the baby, breathing problems, drowsiness and floppiness in the newborn, so the baby is monitored. Long use in pregnancy can cause withdrawal in the newborn. Small amounts pass into breast milk; occasional doses are usually acceptable, but watch the baby for sleepiness or feeding problems and follow medical advice.

Precautions and Warnings

Doctors use it carefully in people with head injury or raised pressure in the skull, lung disease, sleep apnoea, liver or kidney problems, heart attack, biliary tract surgery, thyroid problems, older people, and those with a history of substance misuse. Do not drink alcohol. Do not drive or use machinery after receiving it until fully alert.

Overdose

Overdose causes marked sleepiness, slowed breathing and confusion. It is treated in hospital with oxygen, breathing support and the opioid antidote Naloxone if needed.

Therapeutic Class

Opioid analgesic, mixed agonist-antagonist (kappa agonist, partial mu antagonist).

Storage

Hospital medicine: store as directed on the pack, usually below 30°C, protected from light. Do not freeze. Keep out of the reach of children.