Opioid substitution therapy and withdrawal — structured clinical viva

This is a transfer and risk-communication viva, not an automatic switch. Methadone 100 mg is a substantial full-agonist dose; jumping to buprenorphine without adequate withdrawal precipitates severe withdrawal. One missed dose plus remote heroin use does not equal a safe naltrexone start this week.^[2][4]

QTc 465 ms needs context (sex-specific cut-offs, electrolytes, symptoms, interacting drugs). Krantz et al. frame systematic QTc screening — borderline values prompt review, dose consideration, and shared decisions, not necessarily panic cessation without a plan.^[1]

Buprenorphine transfer usually requires specialist protocol: reduce methadone, wait for objective withdrawal (COWS), then induct carefully. Benefits may include partial-agonist respiratory ceiling and take-home logistics — not zero risk.^[4][6]

Naltrexone implant/XR requires completed detox and is not a one-week “cure.” X:BOT highlights induction difficulty versus buprenorphine–naloxone. Implants are jurisdiction-specific.^[3]

Frame retention mortality: leaving OAT impulsively for unproven online plans raises overdose risk.^[5]