Forensic Medicine and Toxicology
Sociomedical Toxicology: Drug Dependence and Abuse
Sociomedical toxicology for MBBS: dependence, tolerance and withdrawal, tobacco, cannabis, opioids, stimulants and solvents, and the NDPS Act, mapped to NMC code FM12.1.
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Sociomedical Toxicology: Drug Dependence and Abuse
Sociomedical toxicology for MBBS: dependence, tolerance and withdrawal, tobacco, cannabis, opioids, stimulants and solvents, and the NDPS Act, mapped to NMC code FM12.1.
Sociomedical toxicology addresses the social poisons: drugs of dependence and abuse. This chapter defines dependence, tolerance and withdrawal, surveys tobacco, cannabis, opioids, stimulants, hallucinogens and solvents, and outlines the legal framework and the management of dependence in the Indian context.
High-yield: Sociomedical Toxicology: Drug Dependence and Abuse
- Dependence is a compulsion to keep taking a drug, while tolerance is a reduced effect from the same dose over time.
- Withdrawal is the cluster of symptoms that appear when a drug of dependence is stopped, and its features often oppose the drug's own effects.
- The Narcotic Drugs and Psychotropic Substances Act 1985 is the principal Indian law controlling drugs of abuse.
- Tobacco use is a leading preventable cause of death, and its toxic effects come mainly from nicotine dependence and combustion products.
- Cannabis in India is used as bhang, ganja and charas, and acute intoxication causes euphoria, conjunctival congestion and impaired coordination.
- Opioid dependence produces a withdrawal syndrome of yawning, lacrimation, dilated pupils, gooseflesh, cramps and diarrhoea.
- Opioid dependence is managed with substitution using buprenorphine or methadone alongside psychosocial support.
- Alcohol dependence can lead to Wernicke encephalopathy, which is prevented and treated with thiamine given before glucose.
- Amphetamines and cocaine are stimulants that cause euphoria, dilated pupils, hypertension and the risk of stroke and arrhythmia.
- Cocaine can cause coronary spasm, and beta-blockers alone are avoided as they may worsen it through unopposed alpha effect.
- Hallucinogens such as LSD cause perceptual distortion and, occasionally, flashbacks long after use.
- Volatile solvent (inhalant) abuse can cause sudden sniffing death from cardiac arrhythmia.
- Fitness-to-drive and drunkenness examination assesses gait, speech, pupils and coordination and records blood alcohol where relevant.
- Body packing, the concealment of drug packets in the gut, is a medico-legal emergency if a packet ruptures.
- A harm-reduction approach combines detoxification, substitution, counselling and rehabilitation rather than punishment alone.
Key terms in drug dependence
- **Dependence:** A compulsion to continue a drug, with physical or psychological need.
- **Tolerance:** A given dose produces less effect over time, so the dose is escalated.
- **Withdrawal:** Symptoms on stopping, often the opposite of the drug's acute effects.
- **Governing law:** The Narcotic Drugs and Psychotropic Substances Act 1985 controls drugs of abuse in India.
NMC competencies in this chapter
- **FM12.1:** Sociomedical toxicology: dependence, tobacco, cannabis, stimulants, hallucinogens and solvents
Frequently Asked Questions
What is the difference between tolerance and dependence?
Tolerance means a given dose has less effect over time, so more is needed. Dependence is the compulsion to keep taking the drug, with a withdrawal syndrome when it is stopped.
Which law controls drugs of abuse in India?
The Narcotic Drugs and Psychotropic Substances Act 1985 is the principal legislation regulating narcotic and psychotropic substances and penalising their misuse.
How is opioid dependence managed?
With substitution therapy using buprenorphine or methadone alongside counselling and rehabilitation, an approach that reduces harm more effectively than abrupt withdrawal alone.
Why is thiamine given before glucose in alcohol dependence?
Giving glucose first can precipitate Wernicke encephalopathy in a thiamine-deficient person, so thiamine is given before or with intravenous glucose.
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