CNS Drugs: Pharmacology

CNS Drugs Classification

• CNS drugs are divided into two groups: CNS depressants and CNS stimulants
• CNS depressants are further divided into eight subgroups

CNS Depressants

• Sedatives & Hypnotics
• Analgesic & antipyretic
• Anti-Anxiety (Anxiolytic)
• Anaesthetics
• Antidepressant
• Antiepileptic
• Drugs used in Parkinson's disease
• Antipsychotics

Sedatives & Hypnotics

• Insomnia: characterized by inability to sleep, anxiety, and inability to concentrate
• Sedatives: drugs that cause tranquility, comfort, and relaxation without causing sleep
• Hypnotics: drugs that cause natural sleep

Barbiturates

• Therapeutic uses:
  • Sedative in anxiety
  • Hypnotic in insomnia
  • Induction agent in anesthesia
  • Anti-convulsant in epilepsy
• Classification of Barbiturates:
  • Ultra short acting (5-10 minutes): used before general anesthesia (e.g., thiopental)
  • Short acting (2-4 hours): (e.g., secobarbital)
  • Intermediate acting (4-6 hours): (e.g., pentobarbital)
  • Long acting (6-12 hours): (e.g., phenobarbitone)

Non-Barbiturates

• Benzodiazepines:
  • Therapeutic uses:
    • Hypnotic sedative
    • Anxiolytic
    • Anti-convulsant
    • Used in irritable bowel syndrome
    • Muscle relaxant
• Examples of non-barbiturates:
  • Emazepam
  • Diazepam