3. Drugs in health and disease

Question 1

What is chlorpromazine?

Answer 1

A member of the phenothiazines,

antipsychotic and anti-emetic

moderate autonomic effects, strong sedative, moderate EPS

Question 2

agonists vs antagonist drugs

Answer 2

agonists do the thing and elicit a response

antagonists dont do the thing by blocking the receptor

Question 3

chlorpromazine mechanism of action

Answer 3

blocks postsynaptic dopamine receptors in cortical and limbic areas of brain, preventing dopamine excess in brain

leads to reduction in psychotic symptoms e.g. hallucinations and delusions

anti-emetic because block dopamine receptors in chemical trigger zone (CTZ) in brain, relieving nausea and vomiting

Question 4

licensed doses

Answer 4

Doses in BNF are licenses so any higher dose is unlicensed and cannot be prescribed.

Question 5

IM doses considerations

Answer 5

Always give less than oral dose because no first pass metabolism

Give less dose if person v active (more blood flow to muscles = more absorption)

Question 6

Antipsychotic use

Answer 6

short term - calm disturbed patients whatever underlying psychopathology e.g. schizophrenia, brain damage, mania, toxic delirium, agitated depression

alleviate anxiety short term

Question 7

Schizophrenia treatment aims

Answer 7

alleviate suffering of pt/carer
improve social and cognitive functioning

many pts require life-long treatment w antipsych meds

Question 8

What symptoms do antipsychotic drugs drugs relieve?

Answer 8

positive psychotic symptoms e.g. thought disorder, hallucinations, delusions

prevent relapse

less effective on negative symptoms such as apathy and withdrawal

Question 9

Schizophrenia treatment response

Answer 9

neg symptoms persist between episodes of treated positive symptoms but if you treat earlier then can stop neg symptoms developing

acute schiz pts respond better than those w chronic symptoms

Long term treatment usually required after first episode of illness in order to prevent relapses

Doses effective in acute episodes should be prophylaxis

Question 10

First generation antipsychotics

Answer 10

phenothiazine derivatives split into 3 main groups

Block dopamine d2 receptors in brain

not selective so can cause lots of side effects, especially EPS and elevated prolactin

Question 11

Group 1 phenothiazine derivatives

Answer 11

chlorpromazine hydrochloride, levomepromazine, promazine hydrochloride

v sedative, moderate antimuscarinic and EPS

Question 12

Group 2 phenothiazine derivatives

Answer 12

pericyazine
moderate sedative effect
fewer EPS than groups 1 and 3

Question 13

Group 3 phenothiazine derivatives

Answer 13

Fluphenazine deconoate, perphenazine, prochlorperazine and trifluoperazine
fewer sedative and antimuscarinic effects
more EPS than groups 1 and 2

Question 14

Butyrophenones

Answer 14

benperidol and haloperidol

resemble group 3 phenothiazines so fewer sedative and antimuscarinif effects but more EPS

Question 15

Thioxanthenes

Answer 15

Flupentixol and zuclopenthixol

moderate sedative, antimuscarininc and EPS

Question 16

diphenylbutylpiperidines

Answer 16

Pimozide
reduced sedative effect
reduced antimuscarinic effects
reduced EPS

Question 17

Substituted benzamides

Answer 17

sulpiride
reduced sedative effect
reduced antimuscarinic effect
reduced EPS

Question 18

Second gen drugs

Answer 18

AKA atypical antiphsycotic drugs

act on more range of receptors than first-generation antipsychotics

Question 19

Prescribing antipsychotic drugs for elderly

Answer 19

risk-benefit balance

Antipsychotic drugs are associated w small increased risk of mortality and increased risk of stroke/TIA

susceptible to postural hypotension & to hyper/hypothermia in hot.cold weather

Question 20

When should antipsychotic drugs be prescribed in elderly?

Answer 20

1. should not be used in elderly patients to treat mild to moderate psychotic symptoms
2. initial doses should be reduced (to half or less) taking into account weight, comorbidity, other medicaition
3. treatment should be reviewed regularly

Question 21

Prescribing in pts with learning disabilities

Answer 21

if patients are prescribed antipsychotic drugs who aren’t having psychotic symptoms:
1. dose should be reduced/discontinued long term
2. pt’s condition should be reviewed after dose reduction/discontinuation
3.
referral to psychiatrist experienced in pts w learning disabilites and mental health problems
4. annual documentation of re

Question 22

chlorpromazine hydrochloride indications

Answer 22

1. Schizophrenia and other psychoses
2. mania
3. short term adjunctive management of severe anxiety
4. Psychomotor agitation, excitement and violent or dangerously impulsive behaviour
5. intractable hiccup
6. relief of acute symptoms of psychoses
7. nausea and vomiting in palliative care

Question 23

drugs most likely to cause extrapyramidal symptoms

Answer 23

antipsychotic side effects
occur mostly w piperazine phenothiazines (fluphenazine, perphenazine, prochlorperazine, trifluoperazine)
butyruphenones (benperidol and haloperidol) and first generation depot preperations

Question 24

Extrapyramidal symptoms

Answer 24

parkinsonian symptoms inc tremor
dystonia - abnormal face/body movements and dyskinesia
akathisia - restlessness, occurs after large initial doses
tardive dyskinesia, usually on longterm therapy w high doses

Question 25

Can extrapyramidal symptoms go away?

Answer 25

yes
go away if drug withdrawn
can be suppressed by antimuscarinic drugs but not used as can unmask/worse tardive dyskinesia

Question 26

What is the most serious extrapyramidal symptoms?

Answer 26

tardive dyskinesia - can be irreversible on withdrawing therapy, treatment usually ineffective
most likely to occur in kids following withdrawal

Question 27

hyperprolactinaemia

Answer 27

dopamine inhibits prolactin release so inhibiting dopamine increases prolactin conc

risperidone, amisulpride and first gen antipsychotic drugs are likely to cause hyperprolactinaemia

symptoms: sexual dysfunction, reduced bone mineral density, menstrual disturbances, breast enlargement, galactorrhoea

Question 28

aripiprazole prolactin

Answer 28

aripiprazole reduces prolactin because its a dopamine receptor partial agonist

Question 29

sexual dysfunction

Answer 29

side effect of antipsychotics
main cause of non-adherence

reduced dopamine transmission and hyperprolactinaemia decrease libido
antimuscarinic effects cause arousal disorders
alpha1adrenoreceptor antagonists associated w erection and ejaculation problems

risperidone and haloperidol

Question 30

Cardiovascular side effects

Answer 30

tachycardia, arrhythmias, hypotension

QT interval prolongation w haloperidol and pimozide, and IV antipsychotics

Question 31

hyperglycaemia and weight gain

Answer 31

clozapine, olanzapine, quetiapine, risperidone

Question 32

hypotension and interference w temp regulation

Answer 32

dose related side effects liable to cause dangerous falls and hypothermia or hyperthermia in elderly

clozapine, chlorpromazine, lurasidone, quetiapine can cause postural hypotension, associated w syncope or reflex tachy

Question 33

neuroleptic malignant syndrome

Answer 33

hyperthermia, fluctuating consciousness levels, muscle rigidity, autonomic dysfunction w pallor, tachycardia, labile BP sweating and urinary incontinence

rare but potensh fatal side effect of all antipsychotic drugs.

discontinue drug. may be treatable w bromocriptine and dantrolene
usually lasts for 5-7 days after drug discontinued

Question 34

blood dyscrasias

Answer 34

perform blood count if unexplained infection or fever develops