Substance use disorders like opioids, cannabis, tobacco etc

1. Substance use disorder

2. Classification
• Acute intoxication
• Harmful use
• Dependence
• Withdrawl
• Psychotic disorder
• Amnestic disorder
• Residual and late onset psychiatric disorder

3. Etiology

4. Assessment of drug user
• History
• MSE
• Physical examination
• Urine screening
• Blood testing: FBC, LFT, discuss need for HIV/Hepatitis screening

5. Management
• Residential rehabilitation, hospital or community
• Drug users receiving methadone or who misuse stimulants are offered
rewards (e.g. vouchers for goods or services) for negative drug tests or
harm reduction (e.g. hepatitis and HIV tests).
• • Effective psycho-social interventions include cognitive– behavioural
therapy, motivational interviewing (see Chapter 18) and self-help
groups. •
• Medication can be useful (see specific substances below). •
• Infection (HIV and hepatitis C) is the greatest risk associated with
injecting drug use; harm-reduction strategies aim to minimise infection
(e.g. needle exchange) and improve safety.

6. Specific Drugs

7. Opoids
Heroine, morphine, pethidine, codeine, tramadol etc.
Intoxication
Respiratory depression, hypotension, pulmonary edema,hypothermia, Cardiac
conduction defect ( prolonged QRS, arrhythmia, heart block)
Treatment: ABC, Naloxone(0.4-2 mg IV, repeat if necessary)
Withdrawl:
• from 6-24 hrs to 5-7 days
• Clinical findings: flu like symptoms( rhinorrhea, lacrimation), sweating, abdominal
cramping, nausea, vomiting, hypertension, tachycardia, tachypnea etc.

8. Opoid withdrawl
• Treatment: Methadone
• Dosing depends on severity of withdrawl symptoms:
Mild: No prescription
Moderate: 10 – 20 mg
Severe: 20-30 mg
Increase dose till clinical stable, then gradually reduce over 4-6 months
Naltrexone: After completion of detox. Prescribe naltrexone to prevent
relapse.

9. Tobacco
• Consumed via: smoking, chewing
• Addiction occurs due to nicotine.
• Physical effects:
Respiratory: COPD, Asthma, Bronchiectesis, Lung Cancer
CVS: MI, Stroke, Peripheral artery disease
GI: Peptic ulcer disease, alimentary canal cancers.

10. Nicotine withdrawl
• Within 24 hours
• Irritablity, agitation, decrease sleep, increase appetite
Treatment:
1. Nicotine replacement therapy: Nicotine gums (2mg), Nicotine
patches(21 mg)
2. Bupropion
3. Varenicillin

12. Methods of smoking cessation

14. THANK YOU
References
1. Oxford Handbook of Psychiatry
2. Psychiatry at a glance
3. An illustrated coloured textbook of psychiatry
4. Davidsons principles and practice of medicine