Anxiety and sleep disorders Flashcards
what are anxiolytics
used to treat acute anxiety states
what are hypnotics
drugs used to treat insomnia
what type of drug can treat both anxiety states and insomnia
CNS Depressants - effects that range from anxiolytic at low concentrations to sedation, sleep and anaesthesia at higher concentrations
what are the main drugs used
- benzodiazepines
- 5HT1A receptor agonists
- Beta adrenoreceptor antagonists
which drug class replaced barbiturates as a widely used anxiolytic and hypnotic drug
benzodiazepines
why were barbiturates phased out in favour of other drugs
- low therapeutic index
- dependence producing properties
- barbiturates resemble benzodiazepines in increasing the activity of GABAa receptors but increase opening of the channel so much that it can cause severe depressant effects
still useful in anaesthesia
what are the most widely used and most important anxiolytics and hypnotics
benzodiazepines
what do effects do benzodiazepines have
- decrease in anxiety
- a sedative effect
- induction of sleep
- reduction in muscle tone
- anticonvulsant effect
what is the mechanism by which benzodiazepines work
act by binding to distinct benzodiazepine regulatory sites on GABAa receptors to enhance the action of GABA - increasing its affinity for its site on GABA activated Cl- channels - increases frequency of chloride channel opening
discuss the safety of benzodiazepines
very safe on their own - causes severe respiratory depression when taken in conjunction with alcohol
name a short acting benzodiazepine and its use
midazolam - dental phobia
name an intermediate acting benzodiazepine and its use
temazepam - anxiety and insomnia
name a long acting benzodiazepine and its use
diazepam - epilepsy - also muscle relaxant in small doses
which subunit of the gaba receptor does benzodiazepine bind to
the gamma2 subunit - this is essential
name the non-BDZ ligands for the BDZ binding site
ZOLPIDEM
ZOPICLONE
The z drugs - hypnotics as very very sedative
name a BZD site antagonist
flumazenil - many be given in BZD overdose
unwanted effects of BZD
tolerance and dependence
therefore withdrawing the drug can cause withdrawal symptoms
drowsiness, confusion, forgetfulness, some loss of muscle control
how do 5HT1A agonists work
auto-inhibitory presynaptic receptors and activation results in decreased firing of serotenergic neurones - so have an inhibitory effect
name a 5HT1A agonist
buspirone - presynaptic
what is the action of the 5HT1A agonist
reduce anxiety but do not cause the sedation or motor incoordination seen with benzodiazepines
less effective in OCD or PTSD
unwanted effects:
nausea, nervousness, giddiness, restlessness
which beta adrenoreceptor antagonist has an anxiolytic effect
propranolol
which other drug type has sedative effects
antihistamines - H1 receptor antagonists
