Recommended actions pre-op:

All elective surgical patients should attend a pre-assessment clinic and a plan made for their medication assisted treatment (MAT). If patients are on high doses of MAT, consider referral to the Inpatient Pain Management Team and/or contacting the appropriate anaesthetist to assist peri-operative planning.

1. Confirm the dose of MAT and usual dispensing arrangements with the prescriber and the dispensing pharmacist.
2. Ask the patient about current illicit use of substances as well as alcohol and smoking history.
3. Send urine for toxicology screening.
4. If the patient usually takes methadone, perform an ECG.
5. Liaise with the clinical pharmacy team and / or ward staff to ensure that daily doses of MAT are in stock and available to be administered on the ward.
6. The pharmacy team can assist in ensuring a clear plan is in place for discharge. Aim to avoid missed or duplicate doses of MAT.
7. Usual MAT can be given on morning of surgery despite fasting guidelines - use sugar free formulations of Methadone only.

Post operatively:

1. Where surgery allows, continue usual MAT prescription post-operatively and aim to treat pain separately.
   1. MAT rarely provides adequate analgesia alone (see Key points under section 9).
   2. This patient group will likely need larger doses of opioids than opioid naive patients and should be carefully monitored for side effects and toxicity.
   3. It can be useful to calculate the daily oral morphine equivalent dose to guide likely opioid requirements.
2. Where possible, regional anaesthesia / local anaesthesia will be used peri-operatively. Intra-operatively, a variety of analgesics may be used by the anaesthetist. Surgical pain responds well to paracetamol and NSAIDs (when not contraindicated) and should be prescribed in line with local guidance on analgesia.
3. If the surgery would usually require a short course of ‘take home’ analgesia including an opioid prescription such as dihydrocodeine or tramadol, be cautious in this patient group.
   1. This can be added to the patient’s daily dispensing regime if appropriate. Be aware of the risk of take home opioids being taken all at once following discharge.

Guidance for specific MATs:

Buprenorphine, including Buvidal and Espranor, is a partial opioid-agonist with a high affinity for opioid receptors. The effect of an additional opioid is usually reduced. Strong opioids can be given but high doses may be required. Please ensure MAT is continued.

Methadone conversions are not simple or linear – seek advice from the Drug Liaison team or Inpatient Pain Management Team and use an opioid conversion reference to estimate the daily morphine equivalent dose.

When doing an opioid conversion, always reduce the opioid equivalent dose by at least 25% to avoid side effects, oversedation or intoxication. Start conservatively; more can be given if needed.

Advance planning should avoid the problem of withdrawal symptoms for elective patients but staff should be vigilant for signs of withdrawal e.g. sweating, dilated pupils, increased pain (non-wound related), frequent yawning or nausea. If concerned, refer to the COWS protocol - see Opioid dependence suspected or declared by patient.

Lack of oral route

For planned surgery, it is unlikely an oral route will be unavailable for more than 24 – 48 hours. If the patient is expected to remain nil by mouth for an extended period of time, an alternative enteral route e.g. NGT or PEG should be arranged in advance.

If an enteral route becomes unavailable:

• monitor for symptoms of withdrawal and seek specialist advice from the Inpatient Pain Management Team, Anaesthetist or Drug Liaison Service.
• Buprenorphine should still be able to be given sublingually despite a lack of oral route but can be converted to morphine if needed.
• For patients who usually receive MAT who are nil by mouth and experiencing withdrawal symptoms, breakthrough doses of subcutaneous morphine can be given 4 hourly as a short-term measure only.
• For patients with acute pain, as required doses of morphine can be given 2 hourly whilst monitoring for intoxication.
• IV replacement may be needed if the enteral route continues to be unavailable – see Emergency surgical admission.

Resume MAT as soon as clinically appropriate. If doses are omitted for more than three days, seek specialist advice from the Drug Liaison Service regarding re-titration.