1b// Pharmacology of Psychiatry

Question 1

What are the types of treatments in medicine?

Answer 1

Chemical – drugs/medicines (+Immunotherapy)
e.g. drugs for psychosis e.g. drugs for depression

Electrical stimulation
e.g. ECT for depression e.g. neurostimulation for pain syndromes

Structural rearrangement - surgery & orthopaedics
e.g. psychosurgery/deep brain stimulation for severe depression

Talking (pycho) therapies
e.g Cognitive Behaviour Therapy (CBT) e.g. exposure for phobias

Question 2

What are the options on how to classify psychiatric drugs?

Answer 2

1. based on chemical structure
2. based on what illnesses they treat
3. based on their pharmacology

Question 3

What are the pro and cons of classifying drugs based on their chemical structure?

Answer 3

E.g. as the WHO classification system does
Pro- each drug has a unique structure = a fact so easy to allocate data

Con – no use in clinical decision making

Question 4

What are the pros and cons of classifying drugs based on what illnesses they treat?

Answer 4

E.g. antidepressant - antipsychotic – anxiolytic – hypnotic

Pros – easy for Drs to choose a drug as docs make diagnosis

Con –1. many psychiatric medicines work in several disorders
E.g. - antidepressants also treat anxiety and OCD (obsessive compulsive disorder)
E.g. – some antipsychotics used as add on (augmentation) treatment for depression

Con- 2. most psychiatric disorders have multiple symptoms and a single medicine might not treat them all
E.g. symptoms in depression include – anxiety-insomnia-low mood-agitation-loss of pleasure- loss of appetite- poor concentration -loss of libido with likely different neurotransmitter mechanisms

Question 5

What does it mean to classify drugs based on their pharmacology?

Answer 5

Core pharmacology used to classify medicines

Targets neurotransmitters
E.g. instead of antipsychotic – we can say dopamine blocker
E.g. instead of antidepressant – we can say serotonin (or with some drugs noradrenaline or dopamine enhancer)
E.g. instead of hypnotic or anxiolytic – we can say GABA enhancer

Question 6

What are the types of GABA receptors?

Answer 6

GABA-A
GABA-B

Question 7

What does NbN stand for?

Answer 7

neuroscience based on nomenclature

Question 8

What is the benefit of NbN?

Answer 8

makes it clear e.g., Alprazolam -GABA-A PAM

Question 9

What is an example of a GABA-B agonist?

Answer 9

baclofen

Question 10

What do drugs work on?

Answer 10

receptors
neurotransmitter reuptake sites
ion channels
enzymes

*TARGETS ARE IN THE BRAIN
BUT CAN AFFECT SYSTEMS ELSEWHERE IN BODY ESPECIALLY LIVER ENZYMES

Question 11

Describe the basic neuronal principles.

Answer 11

Question 12

What do MAOIs do?

Answer 12

monoamine oxidase inhibitors [MAOIs] for anxiety and depression

work on enzyme activity

Question 13

What do acetylcholinesterase inhibitors treat?

Answer 13

dementias

work on enzyme activity

Question 14

What does lithium do?

Answer 14

lithium blocks glycogen synthase kinase for mood stability

work on enzyme activity

Question 15

What are receptor blockers called?

Answer 15

antagonists

Question 16

What are receptor enhancers called?

Answer 16

agonists

aka stimulate receptors

Question 17

Give examples of antagonists?

Answer 17

E.g. dopamine receptor blockers for schizophrenia
E.g. serotonin receptor subtype antagonists for depression
E.g. histamine receptor antagonists for sleep

Question 18

Give examples of agonists?

Answer 18

E.g. benzodiazepines enhance GABA=> sleep
E.g. guanfacine enhance noradrenaline => ADHD

Question 19

Give examples of drugs that block neurotransmitter block reuptake sites?

Answer 19

Many psychiatric drugs block these reuptake sites so increase neurotransmitter concentration in the synapse to enhance post-synaptic receptor activity

e.g. citalopram – enhances serotonin (= serotonin reuptake inhibitor or SRI)– for depression and anxiety
e.g. desipramine – noradrenaline reuptake inhibitor (NRI)= enhances noradrenaline - for depression
e.g. methylphenidate – dopamine reuptake inhibitor (DRI)- enhances dopamine - for ADHD

Question 20

Give drugs that enhance release sites of neurotransmitters?

Answer 20

e.g. amfetamine for ADHD

they switch the reuptake site direction to enhance release

Question 21

Describe the 5-HT neurotransmitter system.

Answer 21

Question 22

Give examples of ion targeting medicines.

Answer 22

Some drugs block channels so reduce neuronal excitability

Sodium channels
E.g. sodium valproate- epilepsy and mood stabilisation
E.g. carbamazepine - epilepsy and mood stabilisation

Calcium channels
E.g. gabapentin & pregabalin – epilepsy anxiety

Question 23

What are the fast acting neurotransmitters?

Answer 23

Excitatory – glutamate = > 80% of all neurons - pyramidal cells

Inhibitory – GABA = 15% - inter-neurons

=> content e.g. of memory, movement, vision etc.

Question 24

What are the slow acting neurotransmitters?

Answer 24

Slow acting (modulators) – about 5% of all neurons

dopamine – serotonin – noradrenaline -acetylcholine

endorphins and other peptides

=> emotions, drives, valence of memory etc.

Question 25

What are the neurotransmitter system in psychiatric disorders? (6)

Answer 25

Question 26

What are the drugs that treat depression and give examples? (8)

Answer 26

Question 27

What are partial agonists?

Answer 27

Partial agonists – lower max efficacy than full agonists Partial agonists are drugs that bind to and activate a given receptor, but have only partial efficacy at the receptor relative to a full agonist

Question 28

What do partial agonists do?

Answer 28

Improved safety – especially in overdose In states of high neurotransmitter or excess agonist medicine can act as an antagonist E.g. buprenorphine < heroin E.g. aripiprazole < haloperidol E.g. varenicline < nicotine

Question 29

What are inverse agonists?

Answer 29

opposite effects to agonists Inverse agonist binds to the same receptor as agonist but induces a pharmacological response opposite to that of the agonist

Question 30

Give an example of a receptor subtype.

Answer 30

GABA-A receptors

Question 31

What are the 2 sites that neurotransmitters and drugs can act on?

Answer 31

orthosteric site allosteric site

Question 32

What is the difference between orthosteric site and allosteric site?

Answer 32

Some drugs act on the same site as the natural (endogenous) neurotransmitter Others work on different sites on the target proteins E.g. GABA-A receptor is an ion-channel linked receptor GABA binds to the GABA receptor = orthosteric site This binding enhance chloride ion conductance => inhibits neurons => calm the brain Benzodiazepines – barbiturates –alcohol – neurosteroids All act at allosteric sites on the same protein complex They enhance the action of GABA => sedation, sleep, reduce anxiety, anti-epilepsy

Question 33

Compare the 2 dopamine receptor blockers drugs for schizophrenia.

Answer 33

haloperidol clozapine

Question 34

Compare 2 5-HT reuptake blockers.

Answer 34

amitriptyline citalopram for depresion

Question 35

What is allosteric modulation?

Answer 35

Question 36

Answer 36

Y/N

Question 37

Answer 37

Y/N

Question 38

Answer 38

Y/N

Question 39

Answer 39

Y/N