benzodiazepines

what is the moa of benzodiazepines?

increase inhibitory effect of GABA by increasing the frequency of chloride channels

what are the different uses of benzodiazepines?

- sedation

- hyponotic

- anxiolytic

- status epilepticus

- muscle relaxant

how long are benzodiazepines usually prescribed for and why?

only 2-4 weeks - pts commonly develop a tolerance and dependence to them

how should benzodiazepines be withdrawn?

in steps - reducing 1/8th of the daily dose every fortnight

how long can it take to withdraw benzodiazepines?

4 weeks to a year or more

what may happen if benzos are withdrawn too quickly?

benzodiazepine withdrawal syndrome

what are the side effects of benzos

- anterograde amnesia

- drowsiness

- confusion

- hypoventilation

- ataxia - causes falls in elderly

what is a way to remember the side effects of carbamezapine?

CARBA MEAN

what does carba mean stand for?

Confusion

Ataxia

Rashes

Blurred vision

Aplastic anaemia

Marrow suppression

Eosinophilia

ADH release

Neutropenia

what are the features of benzodiazepine withdrawal syndrome?

- insomnia

- irritability

- anxiety

- tremor

- loss of appetite

- tinnitus

- perspiration

- perceptual disturbances

- seizures

what other drug class acts on GABA?

barbiturates

what is the difference in the moa of benzos compared to barbiturates?

benzos - increase frequency of chloride channels

barbiturates - increase duration of chloride channel opening

what are the examples of benzos?

- diazepam

- lorazepam

- midazolam

how are each of the benzos given?

diazepam - down below - rectal

lorazepam - line - IV

midazolam - mouth - buccal

what are the contraindications of benzos?

- acute pulmonary insufficiency

- obsessional states

- phobia states

- sleep apnoea

- unstable myasthenia gravis

what can be used in benzodiazepine toxicity?

flumazenil - GABA-a competitive anatgonist