Psychoactive Substance-Use Disorders: Intoxication, Withdrawal, Treatment and Relapse Prevention

Learning objectives

• Define psychoactive substance use, harmful use, intoxication, withdrawal and substance-use disorder (SUD).
• Recognise alcohol, opioid, sedative, stimulant, cannabis, tobacco and multiple-substance presentations.
• Perform a non-judgemental assessment including medical complications, mental health, HIV/hepatitis, pregnancy, violence and suicide risk.
• Manage immediate overdose and withdrawal emergencies safely.
• Explain psychosocial treatment, medication-assisted treatment, harm reduction, relapse prevention and referral.

1. Essential terminology

2. Principles of assessment

Ask, do not assume

Introduce the topic routinely: “I ask everyone about alcohol, medicines and other substances because they affect sleep, mood, seizures and treatment.” Ask what, how much, how often, route, last use, source, mixing, overdose history and whether the person injects. Clarify the patient’s own goals: safer use, reduction, abstinence, detoxification or treatment of a complication.

Screen for severity and consequences

• Loss of control, craving, failed attempts to cut down, tolerance and withdrawal.
• Work/school impairment, relationship conflict, legal problems, financial harm and unsafe sex.
• Injuries, blackouts, seizures, liver disease, pancreatitis, neuropathy, malnutrition and sleep problems.
• Depression, anxiety, psychosis, trauma, self-harm, suicide, violence and safeguarding.
• HIV, hepatitis B/C, tuberculosis, sexually transmitted infections, pregnancy and injection-related infections.

Validated tools can structure—not replace—clinical judgement: AUDIT/AUDIT-C for alcohol, ASSIST for multiple substances, DAST for drugs, CAGE as a brief alcohol screen, and a withdrawal scale such as CIWA-Ar only when staff are trained and a protocol is available.

Examination and investigations

Record airway, breathing, circulation, temperature, mental state, pupils, respiratory rate, oxygen saturation, glucose, hydration, nutrition and injuries. Look for tremor, sweating, jaundice, needle marks, cellulitis, abscess, endocarditis, neuropathy and liver disease. Targeted tests may include full blood count, electrolytes, renal/liver function, glucose, pregnancy test, ECG, creatine kinase, toxicology, HIV/hepatitis tests and infection work-up. A negative rapid toxicology screen does not exclude use or a dangerous co-ingestant.

3. Emergency approach: intoxication and overdose

ABCDE and observation

1. Call for help; protect staff and patient from violence or falls.
2. Open and protect the airway, place an unconscious breathing patient in the recovery position, suction and prepare ventilation.
3. Give oxygen for hypoxaemia, check respiratory rate and continuous saturation; ventilate if needed.
4. Check glucose and temperature; treat hypoglycaemia according to emergency protocol.
5. Look for trauma, aspiration, seizures, hyperthermia, arrhythmia, serotonin syndrome and anticholinergic toxicity.

Opioid overdose

Typical signs are reduced consciousness, slow or absent breathing, pinpoint pupils, cyanosis and snoring or gurgling. Call emergency help, provide airway support and rescue ventilation. Give naloxone without delaying ventilation:

• Naloxone: 0.4 mg IV/IM/SC, or a lower titrated dose in an opioid-dependent person when respiratory depression is less severe; repeat every 2–3 minutes until adequate breathing. Intranasal products follow their labelled strength and may need repeat doses.
• Continue observation because naloxone may wear off before methadone, sustained-release opioids or potent synthetic opioids. Recurrent respiratory depression requires repeated doses or infusion under senior guidance.

Do not let a revived person leave immediately. Explain precipitated withdrawal, assess for aspiration/trauma and provide overdose-prevention education and take-home naloxone where available.

Alcohol intoxication

Protect the airway, check glucose, assess trauma and monitor ventilation. Do not assume reduced consciousness is “just alcohol”—consider head injury, hypoglycaemia, stroke, opioid co-use or infection. Avoid routine stimulants; use supportive care and treat complications.

Stimulant intoxication

Agitation, paranoia, hypertension, tachycardia, hyperthermia, chest pain or seizures may follow cocaine, amphetamine or other stimulants. Reduce stimulation, monitor temperature/ECG and use a benzodiazepine according to emergency protocol for severe agitation or seizures. Treat hyperthermia with active cooling and urgent senior care. Evaluate chest pain as possible acute coronary syndrome; avoid physical restraint where possible.

Sedative or mixed overdose

Support airway and ventilation. Flumazenil is rarely appropriate because it can precipitate seizures and withdrawal, particularly in mixed overdose or chronic benzodiazepine use; seek toxicology/senior advice. Never give alcohol or another sedative as a home “antidote”.

4. Alcohol-use disorder and withdrawal

Withdrawal spectrum

High-risk features include previous withdrawal seizure or delirium, heavy daily use, serious comorbidity, pregnancy, older age, malnutrition, unstable housing, polysubstance use and lack of support. Do not manage high-risk withdrawal alone in an outpatient setting.

Medication principles

• Benzodiazepines: diazepam or chlordiazepoxide is commonly used in a symptom-triggered or fixed-dose protocol. For example, a trained service may use diazepam 10–20 mg initially and repeat according to a local withdrawal score, with careful observation for oversedation and respiratory depression. Liver disease, older age and respiratory disease often require a shorter-acting option and lower doses.
• Thiamine: give before or alongside carbohydrate when feasible. A common prophylactic example is 100 mg orally daily; suspected Wernicke encephalopathy (confusion, ataxia, ophthalmoplegia) requires urgent parenteral high-dose thiamine according to hospital protocol, often 200–500 mg IV two or three times daily.
• Correct magnesium, potassium, phosphate, dehydration and hypoglycaemia. Treat infection, pancreatitis, bleeding and liver failure.

Never combine unsupervised benzodiazepines with alcohol, opioids or other sedatives. A withdrawal score is not a substitute for clinical observation.

Long-term alcohol treatment

Use motivational interviewing, relapse-prevention counselling, mutual-support groups, family work and treatment of depression, trauma and sleep disorder. Acamprosate, naltrexone or disulfiram may be considered where registered and clinically appropriate; check liver/renal function, opioid use, pregnancy and local availability. Disulfiram requires informed consent and reliable supervision. Naltrexone must not be started while opioids are being used or before an adequate opioid-free interval because it can precipitate withdrawal.

5. Opioid-use disorder

Withdrawal

Yawning, lacrimation, rhinorrhoea, piloerection, myalgia, abdominal cramps, diarrhoea, vomiting, dilated pupils, anxiety and insomnia are distressing but usually not fatal in a healthy adult. Assess dehydration, pregnancy, infection, suicide risk and concurrent alcohol/benzodiazepine dependence. Symptomatic treatment may include fluids, antiemetics, loperamide where appropriate, paracetamol/NSAID if safe, and clonidine under blood-pressure monitoring.

Medication-assisted treatment

• Opioid agonist maintenance: methadone or buprenorphine reduces illicit opioid use, overdose and HIV risk and improves retention. Initiation and dose changes must occur in an accredited programme with observed or closely supervised dosing.
• Buprenorphine: begin only when objective moderate withdrawal is present to reduce precipitated withdrawal; typical sublingual induction is divided low doses followed by titration under a specialist protocol.
• Methadone: start low and increase slowly because the half-life accumulates; ECG and interaction review may be needed. Never use a diverted dose as a self-treatment plan.
• Naltrexone: an opioid antagonist option for selected, fully detoxified patients who can maintain an opioid-free interval and have suitable liver function; it does not treat acute withdrawal.

Offer sterile injecting equipment where legally and locally available, HIV/HBV/HCV testing and treatment, condoms, wound care, overdose education and naloxone.

6. Stimulant, cannabis, sedative and tobacco disorders

Stimulants

There is no universally effective substitution medicine. Treat sleep deprivation, depression, psychosis, cardiovascular complications and malnutrition; use CBT, contingency management where available, motivational interviewing and relapse-prevention planning. Avoid prescribing stimulants or benzodiazepines without a clear specialist indication.

Cannabis

Assess impaired memory, motivation, anxiety, panic, psychosis risk, driving and respiratory exposure. Cannabis can worsen psychosis vulnerability and interact with sedatives. Provide motivational and CBT-based treatment; screen for other substances and suicide risk.

Benzodiazepines and other sedatives

Dependence may develop after regular prescribed or illicit use. Abrupt cessation can cause severe anxiety, seizures and delirium. Use a supervised gradual taper, often converting to a longer-acting medicine where appropriate, with specialist input. Avoid concurrent alcohol/opioids and review the original indication.

Tobacco and nicotine

Ask about cigarettes, shisha and smokeless tobacco. Combine brief advice with behavioural support and nicotine replacement therapy (patch plus short-acting gum/lozenge where available), varenicline or bupropion when suitable and locally registered. Check pregnancy, seizure history, psychiatric symptoms and interactions.

7. Co-occurring mental illness and HIV

Depression, anxiety, PTSD, psychosis and bipolar disorder commonly coexist with SUD. Substance use may be an attempt to manage trauma or symptoms, while intoxication and withdrawal can mimic primary illness. Ask whether symptoms occur only during intoxication/withdrawal or persist during sustained abstinence. Screen for HIV, hepatitis, TB, sexual risk and injection-related infection. Coordinate addiction, mental-health, HIV and primary-care services rather than excluding a patient from one service because another problem exists.

8. Psychosocial treatment and engagement

• Motivational interviewing: explore ambivalence, reflect the patient’s goals and support one small achievable change.
• CBT and relapse prevention: identify triggers, cravings, thoughts, high-risk situations and alternative coping responses.
• Contingency management: structured, ethical reinforcement of treatment goals where programmes can provide it.
• Family and social care: involve supportive relatives with consent; address housing, food, school/work and intimate-partner violence.
• Trauma-informed care: prioritise safety and choice; do not force trauma disclosure before the patient is ready.
• Harm reduction: naloxone, safer injecting information, infection prevention, condoms, planned use reduction and low-threshold follow-up save lives even when abstinence is not yet the goal.

9. Pregnancy, adolescents and safeguarding

Screen privately for pregnancy, coercion, violence, child protection and exploitation. Do not abruptly stop alcohol, opioids or benzodiazepines in pregnancy without medical support; maternal withdrawal can harm both patient and fetus. Opioid agonist treatment is often safer than unstable illicit use and should be specialist-led. Adolescents need confidential, developmentally appropriate care, family involvement when safe, and a safeguarding response to trafficking or sexual exploitation.

10. Discharge and relapse-prevention checklist

1. Document the substance, last use, dependence/withdrawal risk, overdose history and medical/psychiatric diagnoses.
2. Give a written medicine and follow-up plan; reconcile ART, TB therapy, analgesics, sedatives and contraception.
3. Provide warning signs: difficult breathing, chest pain, seizure, severe confusion, high fever, suicidal intent or inability to keep fluids down.
4. Provide naloxone and overdose education when opioid risk exists; teach family or peers rescue breathing and emergency calling.
5. Arrange an actual referral appointment, not just a phone number. Include social worker, peer support, HIV clinic and mental-health care as needed.
6. Plan for lapses without punishment; ask what happened, restore safety and revise triggers/support.

Clinical cases

Quick self-test

1. What are the first three priorities in suspected opioid overdose?
2. Why is abrupt cessation of alcohol or benzodiazepines dangerous?
3. Name four features that increase risk of severe alcohol withdrawal.
4. Why can naltrexone precipitate opioid withdrawal?
5. List three harm-reduction interventions that can be offered even when abstinence is not yet achieved.

Key take-home messages

• Use person-first language and assess substance use routinely and privately.
• Overdose and withdrawal are medical emergencies; ABCDE and observation come first.
• Alcohol and benzodiazepine withdrawal can cause seizures and delirium; opioid overdose requires ventilation and naloxone.
• Medication-assisted treatment, psychosocial care and harm reduction are complementary, not competing approaches.
• Treat HIV, mental illness, trauma, pregnancy, pain and social adversity alongside the SUD.

References and further reading

• World Health Organization. mhGAP training manual: disorders due to substance use: WHO training module.
• World Health Organization. International standards for the treatment of drug use disorders: WHO/UNODC standards.
• World Health Organization. Community management of opioid overdose: WHO guideline.
• World Health Organization. Guidelines for psychosocially assisted pharmacological treatment of opioid dependence: WHO guideline.
• World Health Organization. Opioid overdose fact sheet: WHO fact sheet.
• Uganda Ministry of Health. Consolidated Guidelines for the Prevention and Treatment of HIV and AIDS in Uganda, 2022: Uganda HIV guidelines.