In general terms, explain what anxiolytics do and when these are appropriate for use
- decrease feelings of anxiety
- appropriate when anxiety is no longer serving as a stimulus or motivator but is chronically stimulating the sympathetic nervous system leading to medical and social problems
In general terms, explain what hypnotics do, in relation to sedation
- Sedation refers to the loss of awareness and reaction to environmental stimuli.
- Sedation often causes drowsiness (harmful or desirable depending on life vs surgery)
- Sedation is also anxiolytic
- hypnotics cause extreme sedation which results in further CNS depression and sleep
What is the mechanism of action of Benzodiazepines?
- Benzodiazepines ENHANCE the effect of GABA-an inhibitory neurotransmitter which modulates excitatory pathways in the brain.
- Benzos increase the affinity of GABA to GABA-A receptors
- These are found in the post-synaptic membrane and are ligand-gated receptors which open when bound, allowing Cl- ions to flow into the cell, thus hyperpolarising it
- This inhibits the neuronal activity in areas of the brain associated with anxiety and sleep: GABA-A receptors are highly concentrated in the limbic system (and to some extent RAS-explains the sedative effects)
- (Benzos are absorbed from the GI tract and reach peak levels between 30 minutes and 2 hours)
What is the mechanism of action of Hypnotics?
- Same action of enhancing effects of GABA
- main effect is in the Reticular Acitivating System (made up of CNS-spinal cord and cerebellum-mediates overall level of consiousness)
- hence selective hypnotic over anxiolytic benefits
- They block the brain's response to incoming stimuli
Name 5 Benzodiazepines
Name 2 non-benzodiazepine hypnotics
What are all Benzodiazepines indicated for?
- Short term anxiety
- Insomnia related to anxiety
What are Lorazepam and Diazepam additionally indicated for (and what is the difference between the two)?
- Management of Status Epileptus
- Lorazepam is (ironically) short acting, versus Diazepam being long acting
What is Chloridazepoxide additionally indicated for?
- Alcohol withdrawal in cases of dependence
- long duration of action
What is Temazepam additionally indicated for?
- Sometimes used for its calming effect before surgeries
- Short duration of action
Which patients are Non-Benzodiazepine hypnotics indicated for?
Patients with Insomnia (which could be as a result of MH disorder)
What are the contraindications of both Benzodiazepines and Non-benzodiazepine Hypnotics?
- Neuromuscular respiratory weakness
- Sleep apnoea syndrome
- Not over 60 years old
What are the side effects of Benzodiazepines?
- Continued Drowsiness
- Amnesia and Confusion
Tell me about Ataxia
Ataxia is a neurological sign consisting of lack of voluntary coordination of muscle movements caused by damage to Cerebellum - Symptoms include:
- balance and walking
- tasks that require a high degree of control, such as writing and eating
What are the side effects of non-Benzodiazepine Hypnotics, general and specific?
- Continued Drowsiness
- Increased risk of depression
- Taste Disturbance/metallic taste (Zopiclone)
- Hallucinations/Nightmares (Zolpidem)
What patient education would be pertinent to somebody starting Benzodiazepines and non-Benzodiazepine Hypnotics?
- Drowsiness may continue the next day, so avoiding/taking care when operating heavy machinery or driving-also note this drowsiness might make some stressors more difficult to manage
- long term regular use (>6 weeks) can lead to tolerance and sometimes dependence
- not to be combined with use of other CNS depressants such as alcohol
- In some cases, initially see a paradoxical increase in aggression (just Benzos)
- If stomach upset, try small meal or bowel programme if needed (just non-benzos)