Substance Misuse Question Bank

Before initiating opioid substitution therapy (OST) in custody, perform a Clinical Opiate Withdrawal Scale (COWS) assessment to objectively confirm withdrawal, guide induction dose and prevent overdose - prison healthcare must mirror community standards (equivalence of care).

Per the UK Orange Book (Drug misuse and dependence: UK clinical guidelines on clinical management, 2017) and PHE/NHS England prison healthcare guidance, COWS scores 11 signs (pulse, sweating, restlessness, pupil size, bone/joint aches, rhinorrhoea, GI upset, tremor, yawning, anxiety, piloerection): 5–12 mild, 13–24 moderate, 25–36 moderately severe, >36 severe. Methadone induction is typically 10–30 mg on day 1 (maximum 40 mg given opioid-naïve overdose risk in those with uncertain tolerance), titrating by 5–10 mg every 3–5 days toward maintenance 60–120 mg. Buprenorphine requires COWS ≥8–12 before the first dose to avoid precipitated withdrawal - start 4–8 mg sublingual, escalating to 12–16 mg by day 2–3.

The period immediately following release is the highest-risk window for fatal overdose because of lost tolerance - supply take-home naloxone, deliver harm-reduction education and arrange rapid community keyworker linkage. Refusing OST without clinical assessment, or starting opioids without COWS, breaches equivalence of care and risks fatal overdose.

Remember: Prison OST = COWS first, then titrate; methadone max 40 mg on day 1; supply take-home naloxone on release.

The correct initial methadone dose per the UK Drug Misuse and Dependence Clinical Guidelines (Orange Book, 2017) is 10–20 mg daily, with an absolute maximum of 30 mg on day 1. This patient has objective moderate withdrawal (lacrimation, rhinorrhoea, myalgia, mild anxiety), confirmed opiate use on urinalysis, and no observed dosing history - so tolerance cannot be assumed.

Why low induction matters: Methadone has a long and variable half-life (24–36 hours). Plasma levels accumulate over the first week and peak respiratory depression occurs on days 3–5, not at first dose. Most methadone-related deaths happen during induction in the first 2 weeks, and the risk is multiplied by concurrent benzodiazepines or alcohol. Doses ≥30 mg on day 1 (options A, D, E) carry an unacceptable overdose risk; 5–10 mg (option C) under-treats and risks ongoing illicit opioid use.

Titration: Increase by 5–10 mg every 3–7 days based on Clinical Opiate Withdrawal Scale (COWS) and urinalysis; usual maintenance is 60–120 mg/day. Daily supervised consumption is recommended for ≥3 months after stabilisation.

Guideline: 'Drug misuse and dependence: UK guidelines on clinical management' (Department of Health/PHE, 2017 - the Orange Book).

Remember: Start methadone 10–20 mg (max 30 mg day 1); peak respiratory depression days 3–5; titrate slowly with supervised consumption.

Buprenorphine is optimal for this patient given moderate dependence (0.3g daily, intranasal), employment requiring alertness, and psychosocial stability. As a partial mu-opioid agonist, buprenorphine offers significant advantages over full agonists in this clinical context.

Key advantages of buprenorphine:

• Ceiling effect for respiratory depression (safer overdose profile)
• Less sedation and better cognitive function (critical for employment)
• Flexible dosing - alternate-day or thrice-weekly once stable
• Easier withdrawal long-term compared to methadone
• Lower diversion potential with naloxone combination

Patient factors favouring buprenorphine: moderate (not severe) dependence, employment requiring concentration, psychosocial stability, no polysubstance use, motivated for treatment. The 2017 Orange Guidelines recommend buprenorphine as first-line for suitable patients.

Why not methadone? Equally effective for retention and illicit use suppression, but causes more sedation, cognitive slowing, QTc prolongation, and greater dependence. Reserved for severe dependence, failed buprenorphine, or patient preference.

Induction considerations: Requires COWS ≥11 (moderate withdrawal) before first dose to prevent precipitated withdrawal. Start 2-4mg sublingual, increase to 12-16mg by day 2-3. Target maintenance: 12-24mg daily.

Remember: Buprenorphine = "work-friendly OST" - safer, less sedating, better quality of life for employed, stable patients.