Drugs Acting on Central Nervous System

Drugs Acting on Central Nervous System.

Antipsychotic Drugs

The psychotic drugs are classified in to three major groups:--

(a) Anxiety disorders (phobia and sleeping disorders).

(b) Effective / mood disorders (depression)(c) Personality disorders (Schizophrenia).

A. Anxiolytic Drugs

Benzodiazepines (BZD). Diazepam, Lurazepam, Midazolam.

Mode of action

Binding of GABA  to it's receptor trigger an opening of chloride conductance. The influx of chloride ions causes hyperpolarization that moves the post synaptic of action potential and neural firing.

Actions

Reduction of anxiety (at low doses), Seductive and hypotonic actions (at higher doses), Anticonvulsant , Muscle relaxant.

• Barbiturate.

Mode of action

Interfere with sodium and potassium transport across cell membranes.

Actions

Depression of CNS (at low doses), Hypnosis and anesthesia ( at high doses), Respiratory depression , Enzyme induction ( p-450 microsomal enzyme in liver.

• Busiprone. 
• Useful in the treatment of generalized anxiety disorders.

Actions

Tricyclic/Polycyclic.