Classification and Pharmacological actions of Barbiturates

Barbiturates belong to the class of Sedative and hypnotic drugs. Sedative is a drug which calms the subject without inducing sleep . And hypnotic is a drug which calms a subject by inducing sleep. Barbiturates are seldom used now and had been replaced by Benzodiazepines.

Classification of Barbiturates
Barbiturates are classified in four categories-
1. Long acting- Phenobarbitone
2. Short acting- Butobarbitone , Pentobarbitone
3.Ultra short acting- Thiopentone , Methohexitone

Pharmacological actions of Barbiturates
Barbiturates exert a number of pharmacological effects like-
1. CNS- It depresses the CNS. In low doses it produces drowsiness or sedation. In high dose it causes hypnosis . They also have anticonvulsant property.
2. Respiratory system- Barbiturates exert a dose dependent respiratory depression.
3. CVS- High doses causes decrease in B. P and heart rate.
4. Kidney- They reduce blood flow.
5. Smooth muscle- It decreases motility of bowel.