17 - Treatment of opioid overdose

Treatment of opioid overdose

498 The Maudsley® Prescribing Guidelines in Psychiatry CHAPTER 4 Opioid dependence Prescribing for opioid dependence The treatment of opioid dependence is a rapidly changing and dynamic field. A decade or so ago, maintenance treatment with methadone was the dominant approach. The introduction of buprenorphine in different formulations, the positive experience of unsupervised consumption of opioids during the pandemic and the emergence of ­high-­potency opioids in the illicit supply chain have contributed to a sea-­change in practice.1,2 The pharmacological interventions used for opioid-­dependent people in the UK and most developed countries include: ■ ■Harm minimisation measures, e.g. take-­home naloxone. ■ ■Maintenance treatment with opioid substitution treatment (OST) such as methadone or buprenorphine (Box 4.4). ■ ■Naltrexone for relapse prevention (although patient acceptability of this is low). Treatment of opioid overdose Opioid overdose is a preventable cause of death in the opioid-­using population. This includes overdose of illicit opioids such as heroin and more potent opioids such as fentanyl and nitazenes, and overdose of prescribed opioids such as methadone or buprenorphine. Opioid overdose is characterised clinically by the presence of: ■ ■unconsciousness ■ ■a low respiratory rate (<12) Box 4.4  Considerations when initiating opioid substitution treatment (OST) ■ ■The aim of treatment is to minimise or abolish withdrawal symptoms without endangering the patient. ■ ■All opioids are respiratory depressants. ■ ■Prescribed opioids such as methadone and buprenorphine have low lethal doses in drug-­naïve individuals. ■ ■Even in patients prescribed them long term, tolerance can be lost over a matter of days. ■ ■OST can be fatal, whereas opioid withdrawal is not life-­threatening. ■ ■The undoubted risk of opioid toxicity should be weighed against the risk of self-­discharge from hospital against medical advice because of intolerable opiate withdrawal. Self-­discharge carries risks, with an eightfold increased probability of drug-­related death in the 2 days following ­self-­discharge.3 Opioid-­dependent patients may also delay seeking care for their physical health problems because of the fear of withdrawal.4 ■ ■Non-­specialist doctors should seek guidance either from established local protocols regarding initiation of opioid substitution (opioid agonist) treatment or from specialist drug services before prescribing opioid substitution treatment. ■ ■The key patient safety questions to ask before you prescribe OST are: ■ ■Is OST warranted (i.e. am I confident this patient is currently dependent on opioids)? ■ ■Am I confident that the patient will tolerate the dose of OST I am about to give them? ■ ■It is important to document the reasoning for prescribing or not prescribing.

Addictions and substance misuse CHAPTER 4 ■ ■pin-­point pupils ■ ■cyanosis ■ ■cold, clammy skin. Naloxone is an opioid receptor antagonist that can reverse opioid overdose. It is available in pre-­loaded syringes to give IM or IV or as a nasal spray.4 For patients who have taken buprenorphine, fentanyl or nitazenes,5,6 repeated naloxone boluses may be necessary to reverse toxicity because of their high affinity for opiate receptors. Naloxone injection Naloxone 400mcg IM/IV should be prescribed ‘as required’ for any in-­patient with suspected harmful opioid use or dependence and should be kept in the resuscitation bag on the ward. Anyone can give naloxone to prevent an overdose death. Patients discharged from in-­patient wards should be warned about loss of tolerance and they and their family members should be provided with naloxone training and take-­home ­naloxone.8 A summary of what to do in case of opioid overdose is shown in Figure 4.2 and training in take-­home naloxone covers these actions. Intranasal naloxone Concentrated intranasal naloxone in doses of 2mg per kit is an alternative to intramuscular naloxone4 with greater ease of use and acceptability to lay people.9 The 2mg dose gives an equivalent time to onset of action to 400mcg IM but produces a longer lasting peak.9,10 Call 999 and ask for an ambulance Give basic life support 30 chest compressions and 2 rescue breaths Give naloxone (either IM naloxone 400mcg OR one dose of nasal naloxone) Give 3 cycles of basic life support (30 chest compressions and 2 rescue breaths) if possible Repeat giving naloxone and 3 cycles of life support until ambulance arrives or patient is breathing normally Figure 4.2  Flowchart for naloxone administration. Adapted from WHO (2014).7