Benzodiazepine Summary:

Benzodiazepines are one of the most commonly perscribed drug classes in the western world. The main use is for anxiety-related conditions including insomnia and depression. Depending on teh reason for perscribing, the dose is very important. 

At low doses, benzodiazepines are anxiolytic, however, at high doses they become sedative and hyponotic. 

The mechanism of action for benzodiazepines is through GABA attenuation. Benzodiazepines bind to a recptor that enhances the effect of GABA. They essentially work to increase the length of time that GABA remains on the receptor, thus allowing more negatively charged ions (such as chloride) into the cell. This hyperpolarises the cell and makes them much less excitable.

 

Although there are different types of GABA, and different benzodiazepines will have an affinity for either one or multiple, all benzodiazepines will cause:

  • Sedation at lower doses
  • A reduction in anxiety
  • Anterograde amnesia at higher doses
  • Anticonvulsant activity
  • Muscle relaxant activity

GABA

 


Anterograde Amnesia

his means that you will not remember the events that ocurred on the drug, but are semi concious. Useful for surgeries where the doctor or surgeon needs you to be semi awake but dont want them to remember the surgery


Indications:

  • Depression
  • Schisophrenia
  • PTSD
  • Generalised anxiety disorder
  • Specific phobias
  • Social anxiety disorder
  • OCD

Adverse Reactions:

  • Highly addicitve, so they are usually only used for short amounts of time
  • Abrupt cessation of treatment will cause withdrawal symptoms
  • Confusion
  • Anxiety
  • Agitation
  • Restlessness
  • Rebound insomnia
  • Tension
  • Seizures (sometimes)
  • Tolerance is common for both sleep inducing and anxyiolytic actions
  • Drowsiness
  • Cognitive impariment
  • Respiratory depression
  • Ataxia (higher doses)
  • Confusion
  • Sleep apnoea

Fortunatly, in the event of a benzodiazepine overdose there exists an antidote known as ___. 

 

Flumazenil

This is the antidote for benzodiazepines. It is a GABA antagonist that rapidly reverses the effects of benzodiazepines. As such, it is well known to precipitate withdrawal symptoms.  

Available as IV only.


Common interactions:

  • CNS depressants
    • Agonistic interactions
  • CYP3A4 inhibitors
    • Antifungals like ketoconazole, verapril, omeprazole, erythromyecin, fluoxine, HIV antivirals
  • CYP3A4 inducers
    • St johns wort, carbamazepine, penytoin, rifampicin
       

Drugs:

Alprolazapam

Xanax is commonly used in panic disorders.

Generic Name: Alprolazapam Brand Name: Xanax
Receptor: INSERT Source: INSERT
Main Action: INSERT
Common Dosage: xxx Suitable during pregnancy? INSERT

Clonazepam

Clonazepam is sometimes used as an anti-epliptic.

Generic Name: Clonazepam Brand Name: Rivotril
Receptor: INSERT Source: INSERT
Main Action: INSERT
Common Dosage: xxx Suitable during pregnancy? INSERT

Diazepam

This is the prototype benzodiazepine. It is long lasting, and the most common form prescribed today.

Generic Name: Diazepam Brand Name: Vallium
Receptor: INSERT Source: INSERT
Main Action: INSERT
Common Dosage: xxx Suitable during pregnancy? INSERT

Flunitrazepam

INSERT

Generic Name: Flunitrazepam Brand Name: Rohypnol
Receptor: INSERT Source: INSERT
Main Action: INSERT
Common Dosage: xxx Suitable during pregnancy? INSERT

Lorazepam

Lorazepam is mainly used to treat epilepsy for grand mal seizures.

Generic Name: Lorazepam Brand Name: Ativan
Receptor: INSERT Source: INSERT
Main Action: INSERT
Common Dosage: xxx Suitable during pregnancy? INSERT

Midazolam

Midazolam causes a lot of anterograde amnesia so is commonly used for surgery.

Generic Name: Midazolam Brand Name: Hypnovel
Receptor: INSERT Source: INSERT
Main Action: INSERT
Common Dosage: xxx Suitable during pregnancy? INSERT

Nitrazepam

INSERT

Generic Name: Nitrazepam Brand Name: Mogadon
Receptor: INSERT Source: INSERT
Main Action: INSERT
Common Dosage: xxx Suitable during pregnancy? INSERT

Oxazepam

INSERT

Generic Name: Oxazepam Brand Name: Serepax, Murelax
Receptor: INSERT Source: INSERT
Main Action: INSERT
Common Dosage: xxx Suitable during pregnancy? INSERT

Temazepam

Temazepam is very short acting.

Generic Name: Temazepam Brand Name: Temaze, Normison, Euhypnos
Receptor: INSERT Source: INSERT
Main Action: INSERT
Common Dosage: xxx Suitable during pregnancy? INSERT