Psychopharmacology for psychiatry

Question 1

targets for psychiatric medicines + examples

Answer 1

receptors - dopamine anatagonists
neurotransmitter reuptake sites-SSRIs
ion channels -
enzymes-maois

Question 2

Types of different tretaments in medicine for psych disorders? (4)

Answer 2

• pharma
• pyscho - cbt
• electrical
• surgery

Question 3

how are psychiatric drugs classified?

Answer 3

based on chemical structure
based on illnesses they treat
based on pharmacology

Question 4

pros/cons of grouping drugs based on chemical structure?

Answer 4

WHO classification system
pro - each frug has unique structure so easy to allocate data
con - no use in clinical decision making

Question 5

pros/cons of grouping drugs based on illnesses they treat?

Answer 5

pro - easy for Dr to choose drug as they make diagnosis
cons - many medicines work for several disorders, many psychiatric disorders have multiple symptoms, one drug may not treat them all
multiple symptoms may be based on different neurotransmitter systems

Question 6

how isgrouping drugs based on pharmacology done?

Answer 6

neuroscience based nomenclature, targets neurotransmitters

Question 7

what is the only NT not taken back up by cell

Answer 7

Ach acetylcholine

acetylcholinesterase breaks it down

Question 8

what is a neuron auto-receptor?

Answer 8

usually inhibitory, activated by neurotransmitter it releases
inhibits calcium influx
switches off firing of terminal
reduces neurotransmitter release
(autoregulating neuron firing)

Question 9

what is the most common form of psychiatric drug? give an example

Answer 9

blocking enzyme activity
MOAIs for anxiety/depression block breakdown of serotonin and NA
acetylcholinesterase inhibitors for dementia
lithium blocking glycogen synthase kinase for mood stability

Question 10

give examples of receptor targeting psychiatric medicines

Answer 10

dopamine receptor blockers - schizophrenia
serotonin receptor subtype antagonists - depression
histamine receptor antagonists - sleep/insomnia
benzodiazapines - enhance GABA for sleep
guanfacine - enhance NA for ADHD

Question 11

how do reuptake targeting medicines produce effect?

Answer 11

most neurotransmitters are recycled via reuptake sites
drug blocks reuptake site
increases neurotransmitter concentration in synapse
enhances post-synaptic receptor activity
e.g citalopram SSRI

Question 12

reuptake targeting drugs examples

Answer 12

citalopram SSRI
desipramine - NA reuptake inhibitor (depression)
methylphenidate - dopamine reuptake inhibitor (ADHD)
amfetamine - ADHD swithces reuptake site direction to enhance release

Question 13

key neurotransmitter system in psychiatry and its receptors

Answer 13

5-HT
post synaptic 5-HT1A inhibitory, reduces downstream firing
5HT2A implicated in psychadelic drugs

Question 14

ion channel targeting psychiatric medicines examples (and channels targeted)

Answer 14

Na channels sodium valproate and carbamazepine - epilepsy and mood stabiliser
Ca channels - gabapentin, pregabalin - epilepsy and anxiety

Question 15

how are neurotransmitters categorised?

Answer 15

fast acting - on/off switches (effects on content e.g memory, movements)
slow acting - modulation - not on/off as too slow (effects on emotions/drives)

Question 16

examples of fast acting neurotransmitters

Answer 16

excitatory - glutamate from pyramidal cells

inhibitory - GABA from inter-neurons

Question 17

examples of slow acting neurotransmitters

Answer 17

only 5% of neurons
dopamine
serotonin
acetylcholine
noradrenaline
endorphins

Question 18

drug classes that treat depression

Answer 18

MAOIs
TCAs
SSRIs
SNRIs
receptor antagonists

Question 19

impact of excess glutamate in psychiatric disorders and its treatment

Answer 19

epilepsy - perampanel

alcoholism - acamprosate, ketamine

Question 20

impact of GABA deficiency in psychiatric disorders and its treatment

Answer 20

anxiety

treated by benzodiazapines (gaba enhancers)

Question 21

impact of 5-HT deficiency in psychiatric disorders

Answer 21

depression and anxiety

MAOIs and SRIs

Question 22

role of excess dopamine in psychiatric conditions and their management

Answer 22

psychosis

dopamine receptor blockers

Question 23

role of excess noradrenaline in psychiatric disorders and management?

Answer 23

nightmares

prazosin - blocker

Question 24

role of acetylcholine deficiency in psychiatric disorders and management?

Answer 24

impaired memory/dementia

acetylcholinesterase enzyme blockers

Question 25

what is a partial agonist?

Answer 25

lower max efficacy than full agonists
has improved safety - overdoses
can act as antagonist in states of high neurotransmitter
some intrinsic agonist to allow normal function

Question 26

examples of partial agonists?

Answer 26

aripiprazole
buprenorphine
varenicline

Question 27

what is an inverse agonist?

Answer 27

opposite effects to agonists

role of GABA in dementias and histamine in ADHD

Question 28

what is meant by GABA subtypes?

Answer 28

neurotransmitter has 14 subtypes
receptor made of 5 different proteins
different locations for different receptor subtypes meaning they have different functions

Question 29

comparison of dopamine blocker drug selectivity

Answer 29

haloperidol - very selective, adverse effects due to dopamine receptor block
clozapine - non selective, many adverse effects due to off targets (sedation, weight gain)

Question 30

what is allosteric modulation?

Answer 30

drug acts on different sites of same protein complex e.g benzodiazapines and alcohol (GABA)

Question 31

what is orthosteric binding?

Answer 31

drug binds to same site as endogenous neurotransmitter

Question 32

comparison of serotonin reuptake blocker drug selectivity?

Answer 32

amitriptyline - TCA, less selective. also inhibits histamine and acetylcholine receptor
citalopram - SSRI, adverse effects driven solely by inc serotonin