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)
What does GABA do?
Inhibitory neurotransmitter that is very widely distributed in the neurons of the cortex
Contributes to motor control, vision and many other cortical functions. It also regulates anxiety
