Psychosis - Pharmacology

Question 1

Anti-psychotic drugs are most effective for treating what?

Answer 1

Acute, positive symptoms of psychosis

Question 2

Anti-psychotic drugs can take up to how long to treat positive symptoms of psychosis?

Answer 2

3 months

Question 3

What are some examples of typical anti-psychotics?

Answer 3

Chlorpromazine, thioridazine, haloperidol, zuclopenixol

Question 4

Zuclopenixol is a typical anti-psychotic drug which is given how?

Answer 4

As a depot preparation

Question 5

What is the mechanism of action of typical anti-psychotics?

Answer 5

D2 receptor blockade to increase cAMP

Question 6

What group of side effects are typical anti-psychotics most likely to produce?

Answer 6

Extra-pyramidal side effects

Question 7

What are the 4 main extra-pyramidal side effects?

Answer 7

Acute dystonic reaction, akathisia, Parkinsonism and tardive dyskinesia

Question 8

Extra-pyramidal side effects occur due to D2 receptor blockade where?

Answer 8

In the nigrostriatal pathway

Question 9

How soon after taking an anti-psychotic will an acute dystonic reaction occur?

Answer 9

Hours-days

Question 10

What happens in an acute dystonic reaction?

Answer 10

Involuntary, sustained, painful muscle spasms

Question 11

What can the muscle spasms which occur as a result of an acute dystonic reaction cause to happen?

Answer 11

Extensor spasm of the body, torticollis (abnormal neck posturing) and difficulty swallowing

Question 12

How is an acute dystonic reaction treated? Give an example?

Answer 12

Anti-cholinergics e.g. Prochlorperazine

Question 13

How soon after taking an anti-psychotic drug does akathisia present?

Answer 13

Within a few days

Question 14

What is akathisia? What may patients with this complain of?

Answer 14

An internal restlessness - patients will complain of feeling like they need to move constantly and will feel mentally uneasy

Question 15

Where does akathisia most commonly affect? What may you notice patients doing?

Answer 15

The legs / pacing, wriggling, fidgeting

Question 16

Dysphonia (difficulty speaking) may occur as a result of which extra-pyramidal side effect?

Answer 16

Akathisia

Question 17

How is akathisia treated?

Answer 17

By lowering the dose of anti-psychotic until it stops, or changing drug altogether

Question 18

How soon after taking an anti-psychotic drug does Parkinsonism present?

Answer 18

Usually within a month

Question 19

What are some features of Parkinsonism induced by anti-psychotic drugs?

Answer 19

Resting tremor, rigidity, postural instability and bradykinesia

Question 20

Which anti-psychotic drug is most likely to result in Parkinsonism?

Answer 20

Haloperidol

Question 21

How can Parkinsonism be treated?

Answer 21

Can be treated with anti-cholinergics or can stop the drug

Question 22

How long after taking an anti-psychotic drug does tardive dyskinesia present?

Answer 22

Years later

Question 23

Which extra-pyramidal side effect may persist even after stopping taking the anti-psychotic which was causing it?

Answer 23

Tardive dyskinesia

Question 24

Tardive dyskinesia occurs as a result of what?

Answer 24

Long term anti-psychotic use

Question 25

How will tardive dyskinesia present?

Answer 25

Repetitive, involuntary purposeless movements e.g. grimacing, lip smacking, pursing lips, sticking out tongue

Question 26

Hypothalamic side effects are more likely to occur with which type of anti-psychotic drugs?

Answer 26

Typicals

Question 27

What are some side effects of anti-psychotic drugs that result from D2 blockage in the tubulofundibular pathway in the hypothalamus?

Answer 27

Hyperprolactinaemia and galactorrhoea, gynaecomastia, sexual dysfunction

Question 28

What are some side effects related to sexual dysfunction that anti-psychotics may cause?

Answer 28

Hypogonadism, decreased libido, amenorrhoea, infertility

Question 29

Which ECG change can taking anti-psychotics predispose to? Which type of anti-psychotic is most likely to cause this?

Answer 29

QT prolongation - typicals

Question 30

Dopamine blockade by anti-psychotic drugs can lead to low levels of which hormones? What can this lead to?

Answer 30

Oestrogen and testosterone / osteoporosis

Question 31

What is the mechanism of action of atypical anti-psychotics?

Answer 31

Block many receptors, mostly 5-HT2A > D2

Question 32

Which type of anti-psychotic drugs have a better efficacy against negative symptoms?

Answer 32

Atypicals

Question 33

Name some examples of atypical anti-psychotics?

Answer 33

Olanzapine, quetiapine, risperidone, aripiprazole, clozapine

Question 34

Why should olanzapine be avoided in people with diabetes?

Answer 34

High risk of destabilising blood sugars and causing weight gain

Question 35

Atypical antipsychotics are first line in who?

Answer 35

People who have been newly diagnosed with schizophrenia and those experiencing side effects from typicals

Question 36

What is the major side effect of atypical anti-psychotic drugs? This occurs due to blockade of what?

Answer 36

Metabolic syndrome / 5-HT2

Question 37

What are the features of metabolic syndrome?

Answer 37

Dyslipidaemia, hypertension, weight gain and insulin resistance

Question 38

What are some side effects of anti-psychotic drugs due to histamine blockade? What are the risks of these?

Answer 38

Sedation - risk of falls / increased appetite - risk of weight gain

Question 39

What happens when antipsychotic drugs block alpha adrenergic receptors?

Answer 39

Decreases the alpha 1 adrenergic activity of blood vessels which interrupts the baroreceptor reflex and causes dizziness, lightheadedness and postural hypotension

Question 40

Muscarinic receptors are the targets of what? Blockade of these receptors can cause what symptoms?

Answer 40

Parasympathetic nervous system / dry mouth, blurred vision, constipation, urinary retention

Question 41

When should clozapine be used?

Answer 41

When 2 previous anti-psychotic drugs (one of which must have been an atypical) have failed i.e. 3rd line

Question 42

Clozapine may be of especial benefit to who?

Answer 42

People with negative symptoms and those who are suicidal

Question 43

What is the reason that clozapine is a 3rd line drug?

Answer 43

Agranulocytosis (neutropenia)

Question 44

Describe the monitoring process for people taking clozapine?

Answer 44

Weekly FBCs for the first 6 months, fortnightly for the next 6 months and 4 weekly after that

Question 45

If a patient who is taking clozapine presents with any signs of infection - what is the most important thing to do?

Answer 45

Check FBCs for neutropenia

Question 46

If a patient taking clozapine stops smoking, what should be done? Why?

Answer 46

Decrease the dose since the drug can be metabolised faster

Question 47

Why should patients getting started on clozapine always be in hospital when this is done?

Answer 47

Because it can be cardiotoxic and cause myocarditis

Question 48

What are some reasons that clozapine may cause myocarditis?

Answer 48

IgE mediated hypersensitivity reaction, cytokine release, hypercatecholaminaemia

Question 49

What should you monitor when starting a patient on clozapine? When should you interfere?

Answer 49

ECG, pulse, BP / if ECG shows non-specific ST segment changes this is positive for myocarditis

Question 50

What are some other recognised side effects of clozapine?

Answer 50

Constipation, hyper-salivation, weight gain and seizures

Question 51

Overall, which type of anti-psychotic drug is better? Which one specifically?

Answer 51

Atypical / clozapine

Question 52

What is neuroleptic malignant syndrome? Who does it tend to occur in?

Answer 52

A rare but life-threatening reaction to anti-psychotic medication / most commonly young males

Question 53

How long after starting an antipsychotic or increasing its dose will neuroleptic malignant syndrome occur?

Answer 53

Usually within 10 days

Question 54

What will neuroleptic malignant syndrome present with? What are some signs?

Answer 54

Pyrexia, rigidity and tachycardia / Raised CK and maybe raised WCC

Question 55

What is the management of neuroleptic malignant syndrome? How long should it take to resolve?

Answer 55

Stop antipsychotic drugs, supportive treatment / 1-2 weeks