Pharmacology CNS Flashcards
Which brain structures are primarily involved in Generalized Anxiety Disorder (GAD) as shown in neuroimaging studies?
The amygdala and the prefrontal cortex, with neuroimaging studies often showing decreased connectivity between these two areas in individuals with GAD.
What role does the neurotransmitter GABA play in GAD?
GABA is involved in inhibitory neurotransmission and helps to regulate anxiety. Dysregulation of GABA or GABA receptors has been observed in GAD patients, and GABA agonists can be effective in treatment.
How are serotonin and SSRIs related to GAD?
Serotonin, also known as 5-HT, is a neurotransmitter that is involved in the regulation of mood and anxiety. SSRIs, which increase serotonin levels, have been shown to be effective for the treatment of GAD.
What is the significance of the HPA axis in the neuroendocrinology of GAD?
The HPA axis regulates the stress response, and its overactivation can lead to the release of stress hormones like cortisol and adrenaline/noradrenaline, which are associated with the symptoms of GAD.
What have clinical trials revealed about corticotrophin-releasing factor (CRF) and neuropeptides in GAD treatment?
Clinical trials targeting corticotrophin-releasing factor (CRF) have been unsuccessful. GAD patients are hypersensitive to neuropeptides like cholecystokinin (CCK), but trials investigating CCK antagonists have also been unsuccessful.
How does genetics contribute to GAD ( General Anxiety Disorder)?
While the specific genes are not detailed in the provided material, genetics are believed to play a role in predisposing individuals to GAD, indicating that family history may be a risk factor.
What is a first class medicine for General Anxiety ? Give examples
SSRI (Selective Serotinin Reuptake Inhibitors)
Medicines such as
Sertaline
Paroxetine
Escitalopram
Increases levels of serotinin in the brain to regulate mood and reduce anxiety
What is a second line treatment for GAD?
SNRIs
Serotinin Norepinephrine Reuptake Inhibitors
E.g Duloxetine and Venlafaxine
Increase levels of serotinin and norepinephrine
Third line treatment for GAD
Antiepileptic Agent such as pregablin (lyrica)
Used if there is no respond to SSRI and SNRIs
It works by decreasing abnormal electrical activity in the brain, which can help to reduce anxiety.
Fourth line treatment for GAD ?
Benzodiazepines such as Alprazolam (Xanax)
Diazepam (Valium)
work by enhancing the effect of the neurotransmitter gamma-aminobutyric acid (GABA) in the brain.
How are benzodiazepines classified based on their duration of action?
Benzodiazepines are classified as short-acting (less than 5 hours), short-intermediate (5-24 hours), and long-acting (greater than 24 hours). This classification influences their clinical use, such as using short-acting types for sleep induction due to their rapid elimination.
Where do benzodiazepines bind on the GABA-A receptor?
Benzodiazepines bind to a specific site on the GABA-A receptor between the alpha (α) and gamma (γ) subunits.
What effect does the binding of benzodiazepines have on the GABA-A receptor?
Binding of benzodiazepines to the GABA-A receptor induces a conformational change that increases GABA’s ability to bind to the receptor, enhancing its inhibitory effect.
What happens when GABA binds to the GABA-A receptor in the presence of a benzodiazepine?
GABA binding in the presence of a benzodiazepine causes the chloride channel to open more frequently, leading to an increased flow of chloride ions into the neuron.
What is the result of the increased flow of chloride ions into the neuron?
The increased chloride ion flow hyperpolarizes the neuron, making it less likely to fire, resulting in the calming, anxiolytic effects of benzodiazepines.
