Heroin Withdrawal is a clinical syndrome that occurs after abrupt reduction or cessation of heroin use in individuals who have developed physical dependence. Heroin dependence is a chronic relapsing brain disorder characterized by compulsive heroin-seeking and use despite harmful consequences.

Withdrawal occurs because chronic heroin exposure produces neuroadaptation in the central nervous system. When heroin intake stops, the body develops a state of increased neuronal activity resulting in characteristic physical and psychological symptoms.

Epidemiology

• Heroin withdrawal occurs among individuals with prolonged or regular heroin use

• The severity of withdrawal depends on duration of use, dose, frequency of use, route of administration, and individual factors

• Although heroin withdrawal is usually not life-threatening, severe symptoms increase the risk of relapse and overdose after loss of tolerance

Risk Factors

• Long-term heroin use

• High daily heroin consumption

• Frequent injection use

• Previous withdrawal episodes

• Coexisting mental health disorders

• Poor social support

• Previous unsuccessful attempts to stop heroin use

• Concurrent use of other substances

Pathophysiology

Heroin is rapidly converted to morphine, which binds to μ-opioid receptors in the brain and spinal cord. Repeated stimulation of these receptors causes neuroadaptation involving increased neuronal excitability and changes in neurotransmitter activity.

When heroin is discontinued, reduced opioid receptor stimulation leads to excessive noradrenergic activity, producing autonomic symptoms such as sweating, anxiety, tachycardia, gastrointestinal symptoms, and muscle pain.

Clinical Presentation

Withdrawal symptoms usually begin within 6–12 hours after the last heroin dose, peak within 2–3 days, and gradually improve over several days.

Diagnostic Features

• Myalgia

• Gooseflesh

• Diarrhoea

• Rhinorrhoea

• Lacrimation

• Agitation

• Anxiety

• Insomnia

• Sweating

• Yawning

• Abdominal cramping

• Dilated pupils

• Nausea and vomiting

Additional Features

• Restlessness

• Drug craving

• Irritability

• Increased heart rate

• Increased blood pressure

• Difficulty concentrating

Diagnostic Criteria

Diagnosis is clinical and requires:

• Cessation of or reduction in heavy and prolonged heroin use

• Development of characteristic withdrawal symptoms within hours to days after stopping heroin

Withdrawal is characterized by:

• Dysphoric mood

• Nausea or vomiting

• Muscle aches

• Lacrimation or rhinorrhoea

• Pupillary dilation

• Sweating or gooseflesh

• Diarrhoea

• Yawning

• Fever

• Insomnia

Symptoms should cause clinically significant distress or impairment and should not be better explained by another medical condition or substance withdrawal.

Differential Diagnosis

• Opioid intoxication

• Alcohol withdrawal

• Stimulant withdrawal

• Gastrointestinal infection

• Anxiety disorders

• Acute medical illness causing abdominal symptoms

• Medication-related withdrawal syndromes

Investigations

Diagnosis is mainly clinical.

Investigations help identify complications and coexisting conditions.

Laboratory Investigations

• Urine drug screening

• HIV testing with appropriate counselling and consent

• Hepatitis B and hepatitis C screening

• Full blood count

• Renal function tests

• Liver function tests

• Electrolytes

• Pregnancy test where appropriate

Additional Assessment

• Mental health assessment

• Suicide risk assessment

• Assessment of injection-related complications

• Assessment of other substance use

Management

Treatment Goals

• Relieve withdrawal symptoms

• Prevent relapse to heroin use

• Reduce overdose risk

• Support long-term recovery

• Address medical and psychosocial complications

Non-Pharmacological Management

• Provide psychoeducation regarding opioid dependence and withdrawal

• Use motivational interviewing to support behavioural change

• Provide counselling and relapse prevention therapy

• Encourage therapeutic group therapy in structured rehabilitation settings

• Provide support groups for abstinence

• Educate about HIV and hepatitis transmission risks associated with needle sharing

• Encourage harm reduction practices

• Provide family and social support

• Address housing, employment, and social challenges

Pharmacological Management

Medication to Prevent Relapse and Reduce Heroin Reuse

Methadone 30–120 mg orally once daily for a minimum of 1 year.

Notes:

• Dose should be individualized according to withdrawal symptoms, cravings, and clinical response

• Monitor for sedation, respiratory depression, and drug interactions

• Long-term maintenance treatment reduces relapse and overdose risk

OR

Buprenorphine 2–8 mg orally once daily for a minimum of 1 year.

Notes:

• Dose should be adjusted according to withdrawal symptoms and cravings

• Initiate after objective signs of opioid withdrawal to reduce risk of precipitated withdrawal

OR

Naltrexone 25–50 mg orally once daily for 6 months.

Notes:

• Initiate after complete opioid detoxification

• Confirm absence of opioid dependence before starting treatment

• Monitor adherence and liver function where clinically indicated

Symptomatic Treatment

Difficulty Sleeping

Diazepam 5–20 mg orally once daily for a minimum of 7 days.

Notes:

• Use short-term only due to risk of dependence

• Monitor for sedation and respiratory depression

OR

Promethazine 50 mg orally once daily at bedtime.

Notes:

• Dose should be titrated according to symptom resolution

• Monitor for sedation

OR

Chlorpromazine 50–100 mg orally once daily at bedtime.

Notes:

• Dose should be titrated according to symptom resolution

• Monitor for extrapyramidal symptoms and sedation

Abdominal Cramps

Hyoscine butyl bromide 20 mg orally every 8–24 hours.

Notes:

• Dose should be titrated according to symptom resolution

OR

Diclofenac 50 mg orally every 8 hours.

Notes:

• Dose should be adjusted according to symptom severity

• Avoid or use cautiously in patients with gastrointestinal bleeding, renal impairment, or contraindications to NSAIDs

Diarrhoea

Loperamide 4 mg orally as a stat dose, then 2 mg after each loose stool.

Notes:

• Dose should be titrated according to symptom resolution

• Avoid excessive use because high doses may cause cardiac complications

Referral Criteria

Refer to the next level of care if:

• Severe withdrawal symptoms

• Pregnancy

• Severe dehydration

• Coexisting psychiatric illness

• Suicidal thoughts or self-harm risk

• Severe medical complications

• Failure of opioid substitution treatment

• Need for inpatient rehabilitation

• Suspected overdose risk

Complications

• Relapse to heroin use

• Opioid overdose after loss of tolerance

• HIV infection

• Hepatitis B and hepatitis C

• Depression

• Anxiety disorders

• Social and occupational impairment

• Injection-related infections

Prevention

• Early identification of opioid dependence

• Access to opioid substitution therapy

• Harm reduction programmes

• HIV and hepatitis prevention services

• Psychosocial support

• Long-term follow-up after detoxification

Prognosis

Heroin withdrawal symptoms usually resolve with appropriate treatment. However, relapse is common without ongoing medication-assisted treatment and psychosocial support. Long-term opioid substitution therapy significantly improves recovery outcomes and reduces overdose risk.

Patient Education

• Heroin dependence is a treatable chronic medical condition

• Withdrawal symptoms are temporary but can be distressing

• Do not stop opioid substitution medicines without medical guidance

• Avoid returning to previous heroin doses after stopping because overdose risk is increased

• Attend counselling and follow-up appointments

• Avoid sharing needles to prevent HIV and hepatitis transmission

• Seek urgent medical care for overdose symptoms or severe withdrawal complications