| Drug | Class | Adult | Paediatric | Notes |
|---|---|---|---|---|
| Buprenorphine-naloxone (opioid maintenance)[1] | Opioid partial agonist + antagonist | Sublingual induction 4 mg, repeat 4 mg every 1–2 h to relief (target 8–24 mg/day); maintenance once daily | — | First-line opioid agonist therapy per NIMHANS; lower overdose risk than methadone; precipitates withdrawal if started during opioid intoxication; combined with naloxone reduces injection misuse |
| Methadone (alternative opioid maintenance)[1] | Long-acting opioid full agonist | Start 10–30 mg PO daily, titrate by 5–10 mg every 2–3 days to 60–120 mg/day | — | Where available; daily supervised dispensing initially; ECG for QTc; drug interactions; cautious in respiratory disease |
| Naloxone (overdose reversal)[1] | Opioid receptor antagonist | 0.4–2 mg IM/IV/intranasal; repeat every 2–3 min until response; intranasal 4 mg as community take-home | 0.01 mg/kg IV/IM, repeat | Distribute to opioid users, household members, first responders; reverses respiratory depression but short half-life — observe and re-dose; do not delay if suspected overdose |
| Naltrexone (alcohol or opioid relapse prevention)[1] | Opioid receptor antagonist | Oral 50 mg PO daily; IM 380 mg every 4 weeks | — | Reduces craving and heavy drinking; do not start until ≥7 days opioid-free for opioid use; warn about reduced opioid analgesic response in emergency |
| Acamprosate (alcohol abstinence maintenance)[1] | Glutamate-modulating agent | 666 mg PO TDS (333 mg TDS if <60 kg) | — | Maintenance abstinence after detox; renal dose adjustment; start within 5 days of last drink |
| Varenicline (smoking cessation)[1] | α4β2 nicotinic partial agonist | 0.5 mg PO daily × 3 days, 0.5 mg BD × 4 days, then 1 mg BD × 11 weeks | — | Most effective single agent for smoking cessation; nausea; rare neuropsychiatric symptoms; recently revalidated as safe |
| Nicotine replacement therapy (patch + gum)[1] | Nicotine substitution | Patch 21 mg/24 h × 4 weeks then 14 mg × 2 weeks then 7 mg × 2 weeks; gum/lozenge 2–4 mg PRN for cravings | — | First-line widely available; combine patch (basal) + gum (acute cravings) for higher quit rates |
| Bupropion (smoking cessation)[1] | NDRI antidepressant | 150 mg PO daily × 3 days then 150 mg BD × 7–12 weeks | — | Alternative cessation agent; contraindicated in seizure disorder, eating disorder, MAOI co-use; start 1–2 weeks before quit date |
Diagnosis and pharmacological + psychosocial management of alcohol, opioid, and tobacco use disorders in adults including primary-care brief intervention.