naloxone hydrochloride dihydrate: clinical use

Prescribing considerations

• Naloxone is not a substitute for airway management, ventilation or emergency care.
• Balance restoration of adequate ventilation against abrupt loss of analgesia and precipitated withdrawal where controlled reversal is appropriate.
• Ensure take-home nasal naloxone recipients and potential responders are trained to recognise overdose, administer the device and call 999.
• Nasal absorption may be altered by damaged nasal mucosa or septal defects.
• Buprenorphine toxicity may respond incompletely and require respiratory support.

Contraindications and cautions

• Hypersensitivity to naloxone or an excipient.
• Use particular caution with opioid dependence or substantial opioid exposure, cardiovascular disease, potentially cardiotoxic co-medication and newborns of opioid-dependent mothers.

Monitoring

• Airway, respiratory rate, oxygen saturation, consciousness and response to resuscitation.
• Recurrence of opioid toxicity because opioid effects may outlast naloxone.
• Blood pressure, pulse and cardiac rhythm where clinically indicated.
• Acute withdrawal, vomiting, agitation and return of pain.

Clinical pharmacology

Naloxone is a competitive opioid-receptor antagonist with high receptor affinity and no clinically useful opioid-agonist activity. It is rapidly metabolised in the liver, mainly by glucuronide conjugation, and excreted in urine. Its duration may be shorter than that of the responsible opioid.

Formulation and product differences

• The nasal product is a ready-to-use, single-dose device for rapid emergency use by trained non-medical or healthcare responders; it must not be primed or reused.
• Selected injectable products are clear solutions in ampoules for professional injection or infusion; routes and dilution instructions are product-specific.
• Intravenous administration has the fastest effect; intramuscular administration has a slower onset but may act for longer.

Nasal preparation

Route: Nasal

Strengths: 1.8 mg

Injection

Route: Parenteral

Strengths: 400 micrograms/1 mL, 400 micrograms/mL, 0.4 mg/mL