12.1 Anti-Psychotics Flashcards Preview

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Flashcards in 12.1 Anti-Psychotics Deck (30):
1

What is the theory of the mechanism of depression

Caused by a reduction in monoamines (NA, 5HT)

Maybe a loss of receptors

2

How do we treat Depression?
Steps

Mild 1) CBT and Therapy
Moderate/Severe 2) Specific MOA inhibitor e.g. SSRIs
3) Non selective MOA-i e.g TCA, SNRIs

3

How do we diagnose depression?
How do we grade it?

Need to have 2 or more of: low mood, low energy and lack of enthusiasm for thinks would normally enjoy for at least 2 weeks

We grade it mild, moderate or severe, by secondary symptoms (e.g. suicidal/harmful thoughts, withdrawal from society, previous incidences, FHx)

4

What is depression?

Depression is a feeling of low mood or lack of energy. It can range from being mild, with mood/cognitive changes, to severe which can experience hallucinations

5

What are SSRIs?
What do we treat with them?
How do they work?
Pharmacokinetics?

Advantages?

Disadvantages?

Selective Serotonin Reuptake Inhibitors
Depression

Absorbed: Gut
Metabolised: Liver

Have a Long Half Life, less withdrawal
Safe in Overdose!

Takes 2 weeks to affect and longer to maximise

6

ADRs of SSRIs

Increased energy/motivation can cause suicide
Mania
Extrapyramidal symptoms - Tremor
GI - nausea, vomiting, diarrhoea
Citalopram can cause Long QT

7

DDIs with SSRIs

Metabolised by CYP450
Risk of Bleeding with NSAIDs

8

How do you remember the ADRs of SSRIs?

Sleep - insomnia
Sex - dysfunction
Sweat - anxiety
Stomach - Nausea

9

What are TCAs?
Pharmacokinetics?
Example?

Tricyclic Amines
They act on Muscarinic ACh receptors, Histamine receptors
And they block the reuptake of NA and 5HT

Oral and well absorbed
Lipophillic
Variable 1st Pass Effect
Long Half Life

Amylotriptiline

Very Dangerous if OD (arrhythmia, narrow TW)

10

ADRs of TCAs

Postural Hypotension
Loss of Glandular Secretions (mACh - dry mouth, constipation)
Long QT and Tachycardia
Weight Gain
Sedation
Nausea
Nephrotoxic

11

What is an SNRI?

Serotonin Noradrenaline Reuptake Inhibitor
Used for Unipolar Depression

Short Half Life so withdrawal!

Duloxetine

12

ADRs of SNRIs?

Same as SSRIs but more
Sleep Disturbances
Hypertension
Hyponatraemia

13

What is Schizophrenia?
Caused by?

Mental illness with psychotic symptoms
Thought to be caused by an increase in Dopamine

Change in nigrostriatal (extarpyramidal signs), mesolimbic (emotional response), mesocortical (arousal)

Doesn't explain negative symptoms of PS, maybe 5HT /glutamate involved

14

How do we treat schizophrenia?
How successful is treatment for PS?

1st Gen D2 Antagonists (Ergot Derived)
Atypicals e.g clozapine
1/3 better, 1/3 ok, 1/3 get worse

15

How do D2 antagonists work?

ADRs

They block the D2 receptors in the striatum, this inhibits dopamines action on the indirect pathway. This reduces psychotic symptoms

extrapyramidal symptoms
Can cause hyperprolactinaemia
Weight Gain
Hypotension
Sedation
Can lead to Parkinsonism - tardive dyskinesia
Takes days/weeks to work

16

What are the symptoms of PS?
Positive
Negative

Hallucinations, Delusions, Disturbed Thoughts/Behaviour

Withdrawal, Anxiety, Unusual Speech

17

What is an example of a D2 antagonist?

Haliperidol

18

What is an atypical antipsychotic?
ADRs?

An example? Specific ADRs

Have fewer extrapyramidal symptoms so are first line!

Hyperprolactinaemia
Weight Gain (A LOT)

Clozapine - only use in hospital as need to monitor FBC closely
Agranulocytosis

19

How do we treat anxiety?

CBT and psychological intervention

or antidepressant or antipsychotic may work
May use a benzodiazepine to sedate

20

What is anxiety?

What NTs are believed to be linked?

Fear which is disproportionate to the situation
Sweating, Pale, Tachycardia, Nausea, Lightheaded

NA, 5-HT, GABA

There is usually a cycle of fear and avoidance, leading to the belief that the only cure is avoidance

21

How do we use benzodiazepines in anxiety?
PK?

Act on GABA receptors to sedate

Oral
High Bioavailability
Lipid Soluble
Half Life
Renally Excreted

22

ADRs with Benzodiazepines?
(Anxiety)

Dependence
Tolerance
Addictive
Drowsy, Hypotension, Teratogenic, Blurred Vision

23

What do you give if you KNOW it's a benzodiazepine OD?

Flumazenil to antagonise the GABA receptor sites

24

What is Bipolar Disorder?

Manic Depression

25

What are the signs of mania?

Talking really fast
Jumping Topics
Elation
Overactivity
Can't sit still
Poor judgement
Delusions

26

What do we treat Bipolar with?

NOT anti-depressants as could worsen mania
Mood stabilisers - Lithium, Anti-epileptics (Sodium Valproate)

27

ADRs of Lithium
(Bipolar)

Things to monitor

Lithium is Nephrotoxic (U and E)
Risk in Pregnancy
Thyroid dysfunction

Weight Gain
Memory Problems
Thirst and Polyuria

28

PKs of Lithium
Mechanism of Action?

A: Oral, Once a day
D: Slow release
M: Has a narrow TW (MONITOR)
E: Renal

Competes with Ca2+, Affects 5HT levels

29

What do you do in a lithium OD?

Support and give fluids
Anticonvulsants

Dialysis

30

How do you treat dementia?

AChesterase inhibitors
NMDA antagonists - memantine

They slow the progression of mild (ACh) and moderate + (NMDA) disease