Mechanism of action Benzodiazepines/Diazepam/Clobazem/Clonazepam/Loxazepum:
Binds to specific,high affinity sites on the cell membrane that are adjacent to the GABA receptor(in brain)
↑ Affinity of GABA receptor for GABA.
When GABA binds with it’s receptor →Opening of channel
Entry of from ECF to ICF.
Hyper-polarization & stabilzation of the cell membrane.
Pharmacological effects of Benzodiazepines/Diazepam:
- Muscle relaxation.
[B]On respiratory system:Respiartory depression by-
- ↓ sensitivity to .
- Medullary depression.
- Relief GIT disorder such as IBS.
- Reduce nocturnal HCl secretion.
- No significant effect at theraputic dose.
- IN high dose-↓BP.
Indication of Diazepam/Benzodiazepines/
- Anxiety=as anxiolytic.
- For insomnia.
- Sedation=as sedative.
- Hypnosis=as hypnotic.
- Seizure disorder=Epilepsy.Tetanus,Eclampsia.
- Muscle rigidity=as muscle relaxant.
- As diagnostic aids or for treatment in psychiatry.
- For control of ethanol or other sedative & hypnotic with drawal states.
Adverse effects of Benzodiazepines/Diazpam/Clonazepum:
[A] Over dose:Acute toxic effect (fatal)
[B] Normal dose:Undesired effect
- Hange over effect.
[C] Tolerance & dependency due to prolonged use:
- Pharmacokinetic tolerance:By barbiturate due to rapid metabolism by hepatic microsomal enz,induced by barbiturate.
- Pharmacodynamic tolerance:By BDZ due to down regulation of receptor.
Contraindication of diazepam: Myasthenia gravis.