Sedative and hypnotic

  • At lower dose medicine work as sedative.
  • At higher dose same medicine works as hypnotics.

Mechanism of  action of sedative:-

  • in neuron GABA is present on which receptor like Barbiturates,ion channel receptor and Benzodiazapines is present on which medicine bind and excess of chloride ion enter which hyperpolarise and cause CNS depressant.
  • Barbiturate is GABA mimetic.
  • Barbiturate bind to receptor channel doesn’t open but increases the binding of GABA.
  • Benzodiazapine is facilitatory of GABA.

Barbiturate :-

  • Barbiturate increases the duration of channel opening.
  • Dose response curve is steep so the medicine is unsafe.
  • Highly addictive.
  • Enzyme inducer
  • Antrograde amnesia

Benzodiazapine 

  1. High frequency of channel opening.
  2. Dose response curve flat
  3. less addictive
  4. Antrograde amnesia
  5. less enzyme inducer
  6. Antidote is flumazenil
  • only two barbiturate is commonly used.
  • phenobarbitone-epilepsy.
  • Thiopentane-Anaesthesia 

Benzodiazapine (long acting)

  • Diazepam
  • Flurazepam
  • Nitrazepam
  • Flunitrazepam
  • All form active metabolite.
  • Avoided in elderly patients
  • Avoided in liver failure patients.

Short acting BZD  don’t form active metabolite.

  • S- short acting BZD.
  • T-Temazepam.
  • O-oxazepam
  • L-Lorazepam
  • E-Estazolam.
  • Used in elderly patients.
  • short acting.
  • Used in liver failure patients.
  • Shortest acting BZD- midazolam.

Sleep phase

  • REM(dream remember)
  • Non-REM(dream not remember)
  • If we give benzodiazepines or barbiturate the sleep time get increased but sleep phase doesn’t increase equally.
  • Distortion of sleep artitect.

DOC for insomnia 

  • zolpidem
  • zopiclone
  • Eszopiclone
  • zaleplon

Endocrine physiology