Anxiolytics and Hypnotics Flashcards
1
Q
Hypnotic drugs at low doses help reduce what?
Anxiolytic drugs at high doses help induce what?
A
- Anxiety
- Sleep
2
Q
Why is care needed with most of these drugs?
-How does alcohol affect them?
A
- They can result in tolerance, dependence and withdrawal symptoms
- It has an additive affect, especially in benzodiazepines
3
Q
Benzodiazepines
A
Drug Dose equivalent to 5mg diazepam Length of action Half-life Route of administration Temazepam 10mg Short 11h Oral Oxazepam 15mg Short 8h Oral Lorazepam 0.5mg Short 15h Oral, IV, IM Chlordiazepoxide 15mg Long 100h Oral Diazepam 5mg Long 100h Oral, PR, IV
4
Q
What is the MOA of benzodiazepines?
A
- They potentiate the action of GABA, the main inhibitory neurotransmitter in the brain
- They bind to specific receptors on GABAa resulting in an increased affinity of the complex for GABA
- This leads to an increase in chloride ions flowing into the neuron, hyperpolarising the post synaptic membrane
- This makes them effective hypnotics, anxiolytics, anticonvulsants and muscle relaxants
5
Q
Indications for benzodiazepines?
A
- Insomnia
- Anxiety
- Alcohol withdrawal; chlordiazapoxide
- Akathisia (inner restlessness)
- Acute mania/psychosis
- Epilepsy
- Seizures
6
Q
S.Es of benzodiazepines?
A
Avoid driving due to
- Drowsiness
- Ataxia
- Reduced coordination
- Depress respiration; caution in COPD
- Risk of dependence, especially with prolonged us and shorter acting formula
7
Q
Other options to benzodiazepines?
A
- Short acting hypnotics; zolpidem and zaleplon also act on the benzodiazepine receptor, have a short half life and do not cause a hangover
- Buspirone: a 5-HT 1A receptor agonist useful in treating generalised anxiety disorder. Response may take 2 weeks
- Sedating antihistamines; diphenhydramine (nytol) is avaliable OTC for insomnia but heir long duration can cause drowsiness the next day
- Clomthiazole, meprbamate and chloral hydrate are no longer 1st line sedatives/hypnotics due to their adverse effects
