Psychopharmacology for psychiatry Flashcards
Types of treatment
Chemicals - drugs/meds
electrical stimulation - ECT for depression
structural rearrangement - surgery/orthopaedics
talking (psycho) therapies - CBT
What are three ways of classifying drugs?
Chemical Structure,
Illness Treated,
Pharmacology (what they do e.g. dopamine blocker)
What is a pro and con of classifying by chemical structure?
Each drug can be uniquely classified // no use in clinical decision making
What is a pro and 2 cons of classifying by illness treated?
Easy for doctors to choose // some medicines have multiple functions, some illnesses need multiple symptoms treated
What are the two GABA receptors?
GABA A & GABA B
What is an example of GABA-A agonist?
Alprazolam
treats GAD, anxiety and alcohol withdrawal
muscle relaxant, anticonvulsant, sleep promoting
What is an example of GABA-B agonist?
Baclofen
treats spasticity
decreases alcohol craving
What are the 4 target sites for psychiatry medications?
Receptors,
Neurotransmitter Reuptake Sites,
Ion Channels,
Enzymes
What is the general action of enzyme targeting medications?
Block enzyme activities
What are three examples of enzyme targeting medicines?
Monoamine Oxidase Inhibitors (anxiety)
Acetylcholinesterase inhibitors (dementia)
Lithium blocking glycogen synthase kinase (mood stability
What are 3 examples of receptor antagonists?
Dopamine antagonist (schizophrenia),
serotonin antagonist (depression),
histamine antagonist (sleep)
What are two examples of receptor agonists?
Benzodiazepines enhance GABA (sleep),
Guanfacine enhance Noradrenaline (ADHD)
mimic endogenous neurotransmitter to stimulate activity
Action of reuptake site targeting medicines
Most block reuptake sites to increase NT conc in the synapse to enhance post-synaptic receptor action
Some switch reuptake site direction to enhance release
What are three examples of Reuptake transporter blockers?
Citalopram (serotonin, depression),
Desipramine (noradrenaline, depression), Methylphenidate (dopamine, ADHD)
What is an example of Reuptake transporter enhancer?
Amfetamine - ADHD
What are 2 examples of sodium channel blockers?
Sodium Valproate - epilepsy // Carbamazepine - epilepsy
What are 2 examples of calcium channel blockers?
Gabapentin and Pregabalin - epilepsy
Fast acting NT - 95% of neurons
Excitatory - glutamate. 80% of neurons, pyramidal cells
Inhibitory - GABA. Inter-neurons
affect content e.g. memory, movement, vision
Slow acting (modulators) - 5% of all neurons
dopamine/serotonin/NA/acetylcholine
endorphins and other peptides
controls emotions, drives etc
For glutamate neurotransmitter system, is the change in neurotransmitter an excess or deficiency, and what disorder can it lead to?
Excess,
epilepsy, treated with Perampanel
alcoholism, treated with Acamprosate, Ketamine (blocker)
For GABA neurotransmitter system, is the change in neurotransmitter an excess or deficiency, and what disorder can it lead to?
Deficiency,
anxiety, Benzodiazepines, GABA enhancer
For 5-HT neurotransmitter system, is the change in neurotransmitter an excess or deficiency, and what disorder can it lead to?
Deficiency,
depression/anxiety
treated with SSRIs and NSSRIs, MAOIs, serotonin enhancers
For dopamine neurotransmitter system, is the change in neurotransmitter an excess or deficiency, and what disorder can it lead to?
Excess,
psychosis, treated with Dopamine receptor blockers
For noradrenaline neurotransmitter system, is the change in neurotransmitter an excess or deficiency, and what disorder can it lead to?
Excess,
nightmares, treated with Prazosin blockers
For acetylcholine neurotransmitter system, is the change in neurotransmitter an excess or deficiency, and what disorder can it lead to?
Deficiency,
amnesia/dementia treated with Acetylcholinesterase enzyme blockers
How do partial agonists work?
Lower efficacy than full agonists, will only illicit response sometimes upon receptor binding
What are the advantages of partial agonists?
Improved safety if overdose
can act as antagonists in high neurotransmitter
Which neurotransmitter system do most drugs act on?
5HT system
Aripiprazole
Used instead of haloperidol
Prevents total destruction of dopamine activity. THis prevents parkinsonian motor symptoms. dampened dopamine activity
Inverse agonists
a drug that binds to the same receptor as an agonist but induces the opposite pharmacological response.
Used on GABAergic neurons to create pro cognitive effects in dementia
Receptor subtypes
5 proteins make up a receptor -> multiple different combinations
different subtypes have different actions
How does allosteric modulation work?
Drug binds to a different site of the protein to the neurotransmitter and can cause its effects - Benzodiazepines and enhancing GABA action
GABA and allosteric modulation
GABA-A receptor is an ion-channel linked receptor
GABA binds at the orthosteric site (target site), enhances Cl- conductance -> neuron inhibition and calm brain
Benzodiazepines, alcohol, neurosteroids act on allosteric sites, enhance GABA action -> sedation, reduced anxiety etc
Compare the selectivity and function of haloperidol and clozapine
Both dopamine receptor blockers for schizophrenia
Haloperidol is very selective
Clozapine is non-selective, causes systemic adverse effects like weight gain and sedation
Compare the selectivity and function of amitriptyline and citalopram
Both 5-HT reuptake blockers for depression
Citalopram is an SSRI (selective)
Amitriptyline is non-selective, causes adverse effects from blocking histamine and ACh receptors
