4.10.1 Opioid maintenance prescribing

Opioid maintenance prescribing

ChoiceDrugDosage
For information only: Usual drugs prescribed for substitute prescribingBuprenorphine sublingual tablets 400micrograms, 2mg, 8mgDose: Dose will be titrated depending on the individual patient (max. 24mg daily); withdraw gradually; see BNF for further details
Or
Reserve Suboxone® for when there is a risk of dose diversion for parenteral administration

Suboxone® (buprenorphine 2mg / naloxone 500micrograms; buprenorphine 8mg / naloxone 2mg; buprenorphine 16mg / naloxone 4mg) sublingual tablets

Dose dependent on individual patient (max 24mg buprenorphine daily).Titrate gradually upwards with daily supervised consumption until at least 2 weeks after stable dose reached; see BNF for further details

Or
Methadone oral solution 1mg/mlDose:
Dose will be titrated depending on the individual patient but the maintenance dose range is 60-120mg daily. Do not start (or re-start after a break) above 30mg methadone daily. Titrate gradually upwards with daily supervised consumption until at least 2 weeks after stable dose reached

Prescribing Notes

General Information

  • Supervised self-administration of medication by pharmacists optimises compliance and minimises leakage into the illicit market. However, safety must be balanced against the need to provide a patient-centred approach when considering requests for increased take-home doses. Ideally new patients should be started on a supervision regime of at least 6 days per week for a minimum of three months. After 3 months of supervised consumption an assessment of the patient’s stability should be undertaken.
  • If patients miss methadone or buprenorphine doses for whatever reason, they need to be reassessed for intoxication and withdrawal before methadone administration is recommenced. It may be appropriate to reduce the dose and titrate back up to the original dose if the patient has not had methadone for more than three days, as their tolerance may be reduced. If patients have abstained from methadone for five days or more, they will require an assessment of their tolerance before they are re-inducted onto methadone.
  • Use methadone 1mg/ml. The stronger formulation (10mg/ml) should not be used.
  • Methadone tablets should not be used routinely for opioid maintenance prescribing. They are occasionally prescribed in exceptional circumstances for patients travelling abroad.
  • There is a small evidence base that dihydrocodeine can be used effectively for maintenance. Dihydrocodeine should only be initiated by clinicians with appropriate specialist competencies.
  • Caution is required in prescribing medications for patients who attend out of hours or emergency department (ED) stating they have not had their usual supply of methadone or buprenorphine that day.
  • All medications, in particular methadone, should be stored in a child secure area.

Hospital admission of drug misusers

  • Usually methadone or buprenorphine should not be dispensed as ‘take home’ medicines to avoid any risk of ‘double prescribing’.
  • Drug misusers may be admitted to hospital for treatment of conditions common to other patients or directly related to their drug misuse. In either case, hospital medical staff should take proper account of any drug misuse and any treatment being provided in the community.
  • Adjunctive therapy may be required for the management of opioid withdrawal symptoms. Loperamide may be used for the control of diarrhoea; mebeverine for controlling stomach cramps; paracetamol and NSAIDs for muscular pains and headaches; metoclopramide or prochlorperazine may be useful for nausea or vomiting (see BNF for further details).
  • Seek specialist advice before prescribing lofexidine.
  • Full or comprehensive assessment of drug misusers requires specialist knowledge and expertise.
  • Good communication between hospital and community is essential for safe patient care. Patients will usually have a named keyworker and a named pharmacy. They will be receiving treatment from their own GP, a specialist GP provider, or local drug treatment services .

Acute pain management for drug misusers

  • Contact the relevant pain control team for advice.
  • Drug misusers in pain will have needs for pharmacological and other interventions similar to non-drug users.
  • Acute pain requires full analgesic management in patients dependent on opioids. These patients may have a lower tolerance of pain together with a higher tolerance of opioid analgesic effects
  • If pain is mild to moderate, non-opioid analgesia (as used in the general population) is the initial treatment of choice together with appropriate education and advice.
  • For more severe pain, if opioid analgesia is indicated, the treatment will depend on whether the patient is taking full agonist opioids such as methadone, partial agonist opioids such as buprenorphine, or opioid antagonists such as naltrexone. If the patient is dependent on full agonists the opioid pain relief should be in addition to the usual opioid treatment dose and the amount of pain relief medication titrated against pain while monitoring respiratory function. Sub-therapeutic doses should be avoided.
  • Splitting the dose of methadone in order to control pain is an option for some patients taking methadone (e.g. from once daily to twice daily). If the patient is dependent on a partial agonist, such as buprenorphine, specialist advice should be sought but, if the buprenorphine is continued, especially high doses of full agonist opioids will be required initially, with careful monitoring and anticipated dose reduction in the subsequent 36 to 72 hours.
  • Opioid antagonists such as naltrexone will render opioid analgesia ineffective.
  • Consider symptomatic treatments, e.g. loperamide for the control of diarrhoea; mebeverine for controlling stomach cramps; paracetamol and NSAIDs for pain
  • Pregnant women dependent on opioids and in labour should have full pain management as indicated. Once they are tolerant to their maintenance opioid they will need additional analgesia. However the need for monitoring of the respiratory function of the woman and the foetus or neonate should be taken into account.
  • Newborn infants whose mothers are being maintained on methadone should not be given naloxone post-delivery except on the advice of a paediatrician.
  • It is important to be extremely careful when prescribing additional drugs such as sedatives. It may be necessary, in some cases, to contact the relevant pain control team for further advice on improving pain control.
  • Chronic pain management can be complex and requires good joint working arrangements as well as specialist knowledge. Chronic pain management for patients who are receiving substitute prescribing for drug misuse is not covered in the NI Formulary; information sources include “Alcohol and drug misuse prevention and treatment guidance”  (Department of Health, 2017)