Mental Health Drugs

Question 1

Name a acetylcholinesterase inhibitor

Answer 1

Donepezil (aricept), calatamine, rivastagmine

Question 2

Indications of acetylcholinesterase inhibitors

Answer 2

1) Alzheimer’s disease

Slows down the progression but benefit is often small

Question 3

Mechanism of acetylcholinesterase inhibitor

Answer 3

Reversible acetylcholinesterase inhibitor

The increased acetylchline at synapses which helps due to a loss chonergic system in alzheimers disease

Question 4

Adverse effects of acetylcholinesterase inhibitosrs

Answer 4

Nausea, vomiting and diarrhoea
Fatigue
Dizziness/syncope
Urinary Problems

Question 5

What happens in a cholinergic crisis

Answer 5

Severe nausea, vomiting
Abdo pain
Sweating
Bradycardia
Hypotension
Collapse

Question 6

Caution of acetylcholinesterase inhibitors in

Answer 6

People with heart disaese
Cardiac conduction problems
COPD
Asthma
Peptic Ulcer Disease
Renal Impairment

Question 7

Interactinos of acetylcholinesterase inhibitors

Answer 7

Theoreteically would interact with CP450 enzymes altering other drugs metabolism but no clinical evidence

Question 8

Name tricyclic antidepressants

Answer 8

Amitryptiline, lofepramine

Question 9

Uses of tricyclic antidepressants

Answer 9

1) moderate/severe depression - 2nd line

2) Neuropathic pain –> but at much lower dose e.g. sciatica

Question 10

Action of tricyclic antidepressants

Answer 10

inhibit the neuronal reuptake of serotonin and noradrenaline from the synaptic cleft

This increases their availbalility for neurotransmittion

Also block a wide range of receptors –> histamine, muscarinic, adrenergic, dopamine –> which accounts for the extensive side effecst

Question 11

Adverse effects of tricyclic antidepressants

Answer 11

Blockage of antimuscarininc receptors: dry mouth, constipation, urinary retention, blurred vision

Blockade of histamine and adrenergic recpetors: sedatino and hypotension

Cardiac adverse effects –> arrythmias and ECG changes

Neurological effects: convulsions, hallucitations, mania

Blockade of dopamine receptors: breast changes and sexual dysfunction

Question 12

What happens if you block antimuscarininc receptors

Answer 12

dry mouth, constipation, urinary retention, blurred vision

Question 13

What happens if you block histamine and adrenergic receptors

Answer 13

Sedation and hypotension

Question 14

What happens in overdose of tricyclic antidepressants

Answer 14

Extremely dangerous

Lower bp and arrythmias

Coma and repiratory failure –> may be fatal!!!

Question 15

What happens if you suddenly withdraw tricyclic antidepressants

Answer 15

GI Upset, neurological, influenza-like symptoms and sleep problems

Question 16

Warnings of tricyclic antidepressants

Answer 16

Caution with people at high risk of adverse effects e.g. elderly, CV disease and epiplepsy

Question 17

Interactions of tricyclic antidepressatns

Answer 17

DO NOT GIVE WITH MONOAMINE OXIDASE INHIBITORS –> both increase noradrenaline and serotonin at the synapse –. together thye can precipitate hypertension and hyperthermia or SEROTNONIN SYNDROME

TCA can also increase antimuscuranic, sedative or hypotensive effects of other drugs

Question 18

What line do we usually use TCA?

Answer 18

They are usually 2nd line

This is due to a similar efficacy to other antidepressants but worse side effects and more dangerous in overdose

Question 19

How should we stop doses of TCA

Answer 19

Reduce dose over a 4 week period to avoid withdrawal symptoms

Question 20

Name some SSRIs

Answer 20

Citalopram
Fluoxetine
Sertraline
Escitalopram

Question 21

Uses of SSRIS

Answer 21

1) Depression –> first line for moderate/severe
2) Panic disroder
3) OCD

Question 22

Action of SSRIS

Answer 22

Preferentially inhibit serotonin reuptake from the synaptic cleft –> increased availability for neurotransmission –> improves mood and physical symptoms

Question 23

How do SSRIs differ from tricyclcis

Answer 23

They dont inhibit noradrenaline reuptake and cause less blockade of other receptors

Similar efficacy to TCAs but SSRIs are preferred as they have less side effects

Question 24

Advsere effects of SSRIs

Answer 24

Common: GI disturbance, appetite and weight disturbance and hypersensitivity reactions

Hyponatraemia –> mportant in elderly as may cause confusino and decreased consciousenss

Suicidal thoughts & Behaviours

Lower the threshold and some (citaloprom) prolong the QT interval –> predisposes you to arrhythmias

Increased risk of bleeding

Serotonin syndrome

Question 25

What is serotonin syndrome

Answer 25

Triad of autonomic hyperatctivity, altered mental state and neuromuscular excitation Usually responds to treatment withdrawal and supportive therapy

Question 26

What happens if you suddenly withdraw SSRIs

Answer 26

GI Upset Neurological & flu-like sympomts Sleep disturbance

Question 27

Warnings of using SSRIs

Answer 27

Caution if high risk of adverse effects e.g. epilepsy and peptic ulcer disease Caution in young people --> poor efficacy and increase suicidal thoughts Hepatic impairment --> metabolised by liver so may need dose reduction

Question 28

Interactions of SSRIA

Answer 28

1) MAO --> both increase serotonin --> can cause serotnonin syndrome 2) Avoid in drugs that prolong the QT interval e.g. antipsychotics 3) Give gastroprotection if also taking aspirin/NSAID --> as increased risk of GI bleed 4) Anticoagulants --> both increase thebleeding risk

Question 29

Name benzodiazepines

Answer 29

``` Diazepam Midazolam (short-acting) Temazepam (intermiediate) Lorazepam (long-acting) Chlordiazepoxide ```

Question 30

Uses of benzodiazepines

Answer 30

1) Seizures and status epilepticus --> 1st line - usually lorazepam 2) Alcohol withdrawal reactions - 1st line, usually chlordiazepoxide 3) Sedation for interventional producers --> use short-acting if GA is unnecessary or undesirable 4) Anxiety or insomina --> ONLY USE SHORT TERM TEMAZEPAM

Question 31

How do benzodiazepines work?

Answer 31

Facilitate and enhance binding of GABA to the GABAa receptor | Widespread depressent on neurotransmission --> decrease anxiety, sleepiness, sedationa nd anticonvulsant effects

Question 32

What is GABA

Answer 32

GABAa is a chloride channel that opens when GABA binds GABA is the main inhibitory neurotransmitter in the brain Chloride ions flow into the cell to make it more resistent to depolarisation

Question 33

How does alcohol affect GABA

Answer 33

Alcohol also acts on GABAa receptor and in chronic excessive use the patient becomes tolerant to its presence Therefore abrupt cessation provokes an excitatory state of alcohol withdrawal --> benzodiazepiens can be used to treat this and then reduce their dose in a gradual and more controlled way!

Question 34

Adverse effects of benodiazpeines

Answer 34

Dose depndent --> drowsiness, sedation and coma Overdose --> loss of airway refleces can lead to airway obstruction and death DEPENDENCE --> if used weeks, then get withdrawal if abrupt cessation

Question 35

Warnings of benzodiazepiens

Answer 35

a) ELDERLY --> more susceptibly to effects so give a lower dose b) Avoid in patients with significant respiratory problems or neuromuscuar disease e.g. myasthenia gravis c) Avoid if liver failure --> may precipitate hepatic encephalopathy, if their use is essential (e.g. alcohol withdrawal) then use lorazepam as it relies less on the liver for its elimination

Question 36

Interactions of benzodiazepines

Answer 36

1) Additive effect to other sedative drugs e.g. alcohol and opioids 2) CP450 inhibitor (amiodarone, diltiazem, macrolides, fluconazole, protease inhibitors) As it dependes on CP450 enzymes for elimination, hence inhibitors increase their effect