Anxiolytics & Hypnotics - Bloom Flashcards
What is the lifetime prevalence of Anxiety disorders?
Of generalized anxiety disorders (GAD)?
Very common, 28.8% of people experience it during their lives.
5.7%
What defines generalized anxiety disorder?
What are some symptoms that may be demonstrated?
Persistent anxiety for 1+ months, without a diagnosis of a more specific disorder (eg Phobias, OCD).
Apprehension, hyperattentiveness or distractibility, insomnia, impatience. General SNS arousal and muscle tenseness (“Jittery”)
Recall the stages of sleep ranging from Drowsy to REM. Include the EEG wave findings.
Drowsy: 8-12Hz Alpha waves
Stage I: 3-7Hz Theta waves
Stage II: 12-14Hz Sleep spindles & K complexes.
Stage III: Like stage II, but deeper.
Stage IV: 0.5-2Hz Delta waves
REM: Low-voltage, fast sawtooth waves (like awake)
Which stage of sleep is most dominant?
What neurotransmitter predominates in deep sleep? REM sleep?
Stage 2; about 45% of sleep is in stage 2.
Deep sleep = Serotonin
REM sleep = Norepinephrine
Name 4 classes of medications used presently to treat anxiety and insomnia.
Benzodiazepines
SSRIs
Buspirone
Classical Antihistamines (H1 blockers)
Not presently used are barbiturates. “ACO” (alcohol, cannabis, opiates) have also been replaced.
Where is GABA-A found? GABA-B?
From what amino acid precursor is it synthesized?
GABA-A is found in the CNS, and is the main target of anxiolytics and hypnotics there.
GABA-B is found in the spinal column, and is targeted for skeletal muscle relaxation (Baclofen).
Glutamate.
Where is GABA localized to in the CNS? Try to name 5-6 structures.
Substantia Nigra
Globus Pallidus
Hippocampus
Amygdala
Hypothalamus
Spinal Cord
Describe the structure and function of the post-synaptic GABA receptor.
What results from its activation?
What classes of drugs agonize or antagonize it?
It is a pentameric ligand-gated chloride channel.
Influx of chloride, which generates inhibitory post-synaptic potentials (IPSP).
Benzodiazepines and barbiturates, as well as ethanol & inhaled anesethetics agonize it. Flumazenil antagonizes it.
Describe the location, structure, and function of the 5-HT1A receptor.
What relationship does Buspirone have to it? Does it influence any other receptors?
Presynaptic; A Gi receptor that also opens a K+ channel.
Buspirone is a partial agonist here, and also binds dopamine receptors.
There are around 7-8 listed benzodiazepines that can treat anxiety.
Compare and contrast Alprazolam and Diazepam.
Alprazolam influences the forebrain more, is very short acting, and is appropriate as an antipanic drug.
Diazepam has broader CNS depression, has a long duration, and is also used as a muscle relaxant.
What are the indications for Lorazepam?
What is distinctive about its kinetics? Are there any other benzos that behave this way?
For anxiety as well as insomnia (the only mentioned BDZ for both).
It is not a prodrug; only it and Oxazepam are not converted to active metabolites (Note: Oxazepam is an intermediate of many other BDZ including diazepam).
Besides treating anxiety and insomnia, benzodiazepines are indicated to treat many other conditions.
What else is Diazepam indicated for?
Chlordiazepoxide?
Clonazepam?
Diazepam is a muscle relaxant.
Chlordiazepoxide is for alcohol withdrawal.
Clonazepam treats acute manic episodes.
Try to name 6 CNS effects of benzodiazepines.
(Hint: A couple make them potentially useful for anesthesia)
Anxiolysis
Sedation
Hypnosis
Muscle relaxation
Anterograde amnesia
Anticonvulsant action
What drugs should not be mixed with benzodiazepines?
Any other drug that causes CNS depression (ethanol, H1 blockers) due to additive effect.
Drugs that affect hepatic metabolism (eg Cimetidine inhibits CYPs)
Name 7 symptoms of benzodiazepine withdrawal.
Hint: Two are the conditions they are used to treat.
Anxiety
Insomnia
Irritability
Headache
Hyperacusis
Hallucination
Seizures
How should Benzodiazepine abuse be approached?
Gradual dose reduction to avoid withdrawal effects. Switch to longer-acting drugs.
If acute toxicity, use flumazenil.
What is the mechanism of action of buspirone?
What is it used to treat?
How long until therapeutic effects occur?
5-HT1A receptor agonist
Generalized Anxiety Disorder (GAD)
1-2 weeks
What advantages does busprione have over benzodiazepines?
- Less sedating
- No cross tolerance
- i.e., a pt who develops tolerance to a benzo will not have simultanesouly developed tolerance to buspirone