Drug and Alcohol Abuse — Important Points

1. Commonly abused drugs

The major groups are:

• Opioids
• Cannabinoids
• Coca alkaloids

Most are obtained from flowering plants, while some are obtained from fungi.

2. Opioids

• Opioids bind to specific opioid receptors in the central nervous system (CNS) and gastrointestinal tract.
• Heroin (smack) = diacetylmorphine
• Heroin is obtained by acetylation of morphine.
• Morphine is obtained from the poppy plant, Papaver somniferum.
• Heroin is a depressant and slows down body functions.
• Morphine is an effective sedative and painkiller and is medically useful, particularly after surgery.

NEET fact:
Morphine → acetylation → Heroin (diacetylmorphine)

3. Cannabinoids

• Cannabinoids interact mainly with cannabinoid receptors in the brain.
• Natural cannabinoids are obtained from the inflorescences of Cannabis sativa.
• Cannabis products include:
  • Marijuana
  • Hashish
  • Charas
  • Ganja
• They can affect the cardiovascular system.

4. Cocaine

• Cocaine is a coca alkaloid.
• Obtained from Erythroxylum coca.
• It interferes with the transport of the neurotransmitter dopamine.
• Common names: coke, crack
• It has a powerful stimulant effect on the CNS.
• It can produce euphoria and increased energy.
• Excessive doses can cause hallucinations.

5. Hallucinogenic plants

Important examples:

• Atropa belladonna
• Datura

These plants have been used historically in folk medicine and religious rituals.

6. Other drugs that may be abused

Examples include:

• Barbiturates
• Amphetamines
• Benzodiazepines

Although many have legitimate medical uses, their misuse can be harmful.

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Tobacco and Smoking

Nicotine

• Tobacco contains nicotine, an alkaloid.
• Nicotine stimulates the adrenal gland.
• This causes release of:
  • Adrenaline
  • Nor-adrenaline
• Effects:
  • Increased blood pressure
  • Increased heart rate

Harmful effects of smoking

Smoking is associated with increased risk of:

• Lung cancer
• Urinary bladder cancer
• Throat cancer
• Bronchitis
• Emphysema
• Coronary heart disease
• Gastric ulcer

Tobacco chewing

• Associated with increased risk of oral cavity cancer.

Carbon monoxide

Smoking increases CO concentration in blood.

CO binds strongly with haemoglobin, forming carboxyhaemoglobin, thereby reducing the oxygen-carrying capacity of blood and causing oxygen deficiency in tissues.

⭐ Most Important NEET Facts

Drug/substance	Source	Major point
Heroin	Papaver somniferum	Diacetylmorphine; CNS depressant
Morphine	Papaver somniferum	Sedative & painkiller
Cannabinoids	Cannabis sativa	Affect cannabinoid receptors
Cocaine	Erythroxylum coca	CNS stimulant; affects dopamine
Nicotine	Tobacco	Increases BP and heart rate
CO	Tobacco smoke	Reduces oxygen transport

Exam shortcut:
Papaver → Morphine → Heroin
Cannabis → Cannabinoids
Erythroxylum → Cocaine
Tobacco → Nicotine → ↑BP + ↑Heart rate