Week 10 - Anxiolytics Flashcards
Name some anxiety disorders
Generalised anxiety disorder Panic disorder Phobias Post-traumatic stress disorder OCD
What are the effectors that enhance GABA receptor activity?
Allosteric activators
-include ethanol, neurosurgical, barbiturates and the benzodiazepines
Name the types of anxiolytics
Benzodiazepines
Non-benzodiazepines (second generation)
Sedative-hypnotics
How do anxiolytics act?
- non-specific CNS depressants
- alleviate symptoms of distress but do not affect the underlying factors that cause anxiety
- dose dependant, with increasing doses resulting in sedation and then hypnosis
Name some sedative hypnotics and what they are used for
Thiopental (barbiturates - short acting) - prep for surgery
Seconarbital - insomnia, anxiety, acute agitation
Phenobarbital - insomnia, anxiety , seizures
Zolpidem - insomnia
What are the adverse effects of sedative hypnotics?
- avoid other CNS depressants (e.g. Alcohol - risk of respiratory failure)
- check for suicidal tendencies
- drowsiness or hangover
- dependence and tolerance (possible seizure on withdrawal)
Contraindications - under 18’s, pregnant or nursing mothers
Name some benzodiazepines and what they treat
Diazepam (Valium) - anxiety and seizures
Alprazolam - anxiety and panic disorders
Temazepam - short term treatment of insomnia
Lorazepam - anxiety, status epilepticticus, pre-op sedation, amnesia
What are the advantages of benzodiazepines in comparison to barbiturates?
Benzodiazepines:
- effective anxiolytics but don’t cause over sedation
- have a low incidence of tolerance
- very safe therapeutic index
When do benzodiazepines work the best?
- work to quickly reduce anxiety symptoms with the most improvement occurring within the first week of treatment
- efficacy of BZD therapy decreases after 3-4 months of continuous use
As well as anxiety and panic disorders, what are benzodiazepines also used to treat?
- seizure control (notably in acute alcohol withdrawal)
- sleep induction for insomniacs
- pre-op relaxation
What are the side effects of benzodiazepines?
Contraindications - renal and hepatic dysfunction, glaucoma, pregnancy and lactation
- avoid other CNS depressants
- accumulation of metabolites leads to over sedation and CNS depression and ataxia (loss of full control of body movements)
- anticholinergic effects (headache, dry mouth, blurred vision, dizziness, memory loss, hypotension, GI disturbances)
- “date rape”- flunitrazepam - potent when combined with alcohol
What should be considered when giving older people benzodiazepines?
- over relaxation and ataxia are the most common side effects
- older people more susceptible to falls
- so BZDs with a short-acting half life that don’t accumulate are preferred such as temazepam or lorazepam
Name a non-benzodiazepine anxiolytic and what it treats
Buspirone - short term treatment of anxiety and depression
What drug family can be used in the short term treatment of anxiety disorders?
Azapirone drugs (buspirone)
- gradual onset to efficacy of approx 1-4 weeks and is often used as a co-therapy when a pt is coming off BZDs or in treating depression that often accompanies anxiety
- thought to act as a partial agonist on postsynaptic 5-HT1a receptors, rather than on GABA receptors
What are the side effects of non-benzodiazepine anxiolytics?
- avoid other CNS depressants (buspirone increases effects)
- never with MAOIs (can lead to possibly lethal elevation of BP)
-anticholinergic effects (dizziness, headache, insomnia, nausea, dry mouth, blurred vision, mood changes and palpitations)
