Flashcards in Benzodiazepines Deck (13):
Name some common benzodiazapienes?
Diazepam and Lorazepam and Midazolam
What are the common uses of Diazepam?
1. Seizures/Status Epilepticus - first line
2. Alcohol withdrawal - first line
3. Sedation for interventional procedures,
if general anaesthesia is unnecessary or undesirable.
4. Anxiety - For short-term treatment of severe, disabling or distressing anxiety
5. Insomnia - short-term treatment of severe, disabling or distressing insomnia.
**1 and 2 are the main uses for diazepam
**4 and 5 require a quick acting one e.g. temazapam
**3 medazolam used for sedation
What are the contra-indications of using diazepam?
- Respiratory impairment
- Neuromuscular disease (e.g. myasthenia gravis)
- Liver failure as they may precipitate hepatic encephalopathy
When should diazepam be used with caution?
In the elderly
What are the common interactions with benzodiazepines?
- Other sedating drugs e.g. alcohol and opiods
- CYP450 inhibitors as they are metabolised by the liver so these drugs may enhance their effects
What are the side effects of benzodiapines?
- Drowsiness, sedation and coma
- In overdose there is less respiratory depression than in opioids but there is a decrease in airway reflexes which can cause airway obstruction and death
- Withdrawl if suddenly stopped
How is diazepam excreted?
- Hepatically metabolised
- Excreted in urine
How do benzodiazepines work?
Benzodiazepines work on the GABA receptor.
By binding to the GABAa receptor and enhancing GABA binding to the receptor benzodiazepines cause an increase of Chlorine into the cell reducing chlorines presence in the synaptic cleft.
This causes a reduction in synaptic transmission.
What overall effects to benzodiazepines have?
Increased Sleepiness/Drowsiness and sedation
What other substance also works on the GABAa receptor?
Ethanol (alcohol) so long term use can cause patients to become tolerant
What happens when you have sudden withdrawal of alcohol?
There is no longer the inhibition of the GABA receptor so you get an excitatory withdraws effect than can be life threatening
Why can benzodiazepines be used in alcohol withdrawal?
Like alcohol benzodiazepines have an effect on the GABA receptor so when withdrawing people from alcohol to avoid the excitatory effect of alcohol withdrawal benzodiazepines can be used in a more controlled gradual way.