Pharmacology of psychosis Flashcards
In which ways can we classify drugs?
based on chemical structure - used by WHO, easy to allocate data but no use in clinical decision making
based on which illnesses they treat e.g. antidepressant, antispychotic
based on pharmacology: neuroscience based nomenclature (dopamine blocker, serotonin enhancer)
What is Chlorpromazine?
First ever drugs for schizophrenia
What is Haloperidiol?
The 2nd anti schizophrenia drug
What may be the con to classifying drugs based on which illnesses they treat?
May treat more than one illness
most psychiatric disorders have multiple symptoms and a single med may not treat them all
Which drugs are an example of enzyme blockers?
monoamine oxidase inhibitor
acetylcholinesterase inhibitors for dementias
lithium blocks glycogen synthase kinase for mood stability
Which drugs are an example of receptor targeting medicines? 3
Dopamine receptor blockers for schizophrenia
Serotonin receptor subtype antagonists for depression
histamine receptor antagonists for sleep
Can you give some agonist examples which stimulate receptors? 2
benzodiazepines - enhance GABA to allow for sleep
Guanfacine enhance noradrenaline, helps ADHD
Why do some drugs target reuptake sites?
Reuptake sites are were neurotransmitters are recovered and recycled.
this would increase the neurotransmitter concentration in the synapse to enhance the post synaptic receptor activity
What drugs are examples of reuptake site targeting medicine? 3
Citalopram - enhances serotonin for depression and anxiety
desipramine - noradrenaline re-uptake inhibitor for depression
methylphenidate- dopamine uptake inhibitor enhances dopamine for ADHS
How does Amfetamine work for ADHD?
Switches the reuptake site direction to enhance release
Describe the 5 HT neuron reuptake system?
the 5HT - serotonin releasing neuron.
Once the serotonin is released it is taken back up at the pre synaptic membrane by 5HT 1B/D receptors which inhibits its own further release
and also uptaken by the 5HT 1A
If these are both blocked by SRIs then serotonin will increase
–> post synaptic 5HT1A is an inhibitory receptor, serotonin release dampens down activity where that receptor is and can help anxiety
Which drugs are example of ion channel targeters?
Usually block the channels
Sodium channel blockers : sodium valproate - epilepsy and mood stabilisation
carbamazepine - epilepsy and mood stabilisation
Calcium channel:
Gabapentin and pregabalin - epilepsy and anxiety
Which fast acting neurotransmitters are there?
Excitatory - Glutamate, pyramidal cells and 80% of neurons
Inhibitory - GABA, interneurons and 15% of neurons
- both are amino acids
What slow acting modulating neurotransmitters are there?
5% of neurones
dopamine, serotonin, noradrenaline, acetylcholine
endorphins and peptides
drives emotions, Valence of memory etc
What if glutamate is in excess?
Epilepsy
Alcoholism
