Medicines In Psychiatry

Question 1

4 types of treatments?

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

How does WHO classification system classify drugs?

Answer 2

Based on chemical structure

Question 3

What is the problem with classifying drugs based on what illness they treat?

Answer 3

Some drugs treat multiple illnesses

Question 4

Examples of drugs that block enzyme activities?

Answer 4

-monoamine oxidase inhibitors [MAOIs] for anxiety and depression
-acetylcholinesterase inhibitors for dementias
-lithium blocks glycogen synthase kinase for mood stability

Question 5

Examples of receptor blockers (antagonists)?

Answer 5

-dopamine receptor blockers for schizophrenia
-serotonin receptor subtype antagonists for depression
-histamine receptor antagonists for sleep

antagonists block endogenous agonist binding to the receptor

Question 6

Examples of agonists?

Answer 6

-benzodiazepines enhance GABA for sleep
-guanfacine enhance noradrenaline for ADHD

agonists mimic the endogenous agonist and stimulate the receptor

Question 7

Reuptake site targeting medicines? Block

Answer 7

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

Question 8

Reuptake site targeting medicines? Enhance

Answer 8

amfetamine for ADHD

Question 9

Sodium ion channel blocker medicines?

Answer 9

-sodium valproate- epilepsy and mood stabilisation
-carbamazepine - epilepsy and mood stabilisation

Question 10

Calcium ion channel blocker medicine?

Answer 10

gabapentin & pregabalin – epilepsy anxiety

Question 11

Fast acting neurotransmitters?

Answer 11

Excitatory – glutamate = > 80% of all neurons - pyramidal cells
Inhibitory – GABA = 15% - inter-neurons

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

Question 12

Slow acting neurotransmitters?

Answer 12

dopamine – serotonin – noradrenaline-acetylcholine
endorphins and other peptides

emotions, drives, valence of memory etc.

Question 13

Excess glutamate disorder with treatment

Answer 13

Epilepsy - perampanel

Alcoholism - acamprosate, ketamine

treatments all blockers

Question 14

GABA deficiency disorder with treatment?

Answer 14

Anxiety - benzodiazepines (GABA enhancer)

Question 15

5HT deficiency disorders and treatments

Answer 15

Depression and anxiety - SRIs and MAOIs - serotonin enhancers

Question 16

Dopamine excess disorder and treatment?

Answer 16

Psychosis - dopamine receptor blockers

Question 17

Noradrenaline excess and treatment?

Answer 17

Nightmares - prazosin (blocker)

Question 18

Acetylcholine deficiency disorder and treatment?

Answer 18

Impaired memory/dementia - acetylcholine esterase enzyme blockers

Question 19

Partial agonists?

Answer 19

Lower max efficacy than full agonists
Improved safety
In states of high neurotransmitter or excess agonist medicine, can act as an antagonist

Aripiprazole - anti-psychotic with less Parkinsonism symptoms

Question 20

Inverse agonists

Answer 20

Opposite effects to agonists

GABA - reverse amnestied effects
Histamine - increases attention

Question 21

Allosteric modulation

Answer 21

Sites on receptors where things can bind other than target protein

GABA binds to GABA receptor = orthosteric site -> enhanced chloride ion conductance -> inhibits neurones -> calms brain

Question 22

Benzodiazepines, barbiturates, alcohol, neurosteroids similarity?

Answer 22

All act at allosteric sites on same protein complex
Enhance action of GABA -> sedation, sleep, reduced anxiety, anti-epilepsy

Question 23

Selectivity cons?

Answer 23

If too selective, can totally block receptor - negative

If very unselective, can bind to other receptors so cause adverse effects. Can also be helpful - block other side effects