Anti-psychotics in Schizophrenia Flashcards

1
Q

Do first or second generation anti-psychotics have greater efficacy?

A

Both first and second generation anti-psychotics are used to treat the positive symptoms of Schizophrenia (hallucinations, delusions etc) and for this they have the same efficacy aside from Clozapine.
However second generation anti-psychotics have been shown to be have superior efficacy for negative symptoms of Schizophrenia and therefore you may choose these if negative symptoms predominate.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

List some of the first generation anti-psychotics.

A

Chlorpromazine
Haloperidol
Flupentixol
Levomepromazine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

List some of the second generation anti-psychotics.

A

Clozapine
Quetiapine
Aripiprazole
Risperidone
Olanzapine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What does choice of anti-psychotics depend upon?

A

Past history of response
Has the patient been sensitive to a particular adverse effect/or have they got risk factors
Co-morbidities
Concurrent medication which would pre-dispose a particular side effect and interactions
Dosing profiles
Is a depot formulation of the anti-psychotic available to switch to - other formulations - swallowing difficulties
Patient preference
Likely risk vs benefits
Anti-psychotic side effect profile
Cost

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the depot (long acting) anti-psychotic formulations?

A

Involves the administration the anti-psychotic by injection intramuscularly and then is released in the blood over a number of weeks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Which depots need a test dose beforehand?

A

To make this clear all anti-psychotics before being given as depots must have a trial period in the oral formulation to determine efficacy and side effect profile, however:

First generation depots are oil based and require a test dose for sensitivity to the oil base/test for EPSEs

Second generation no test dose is required due to having an aqueous base and lower incidence of EPSEs.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are the main side effects associated with the first generation anti-psychotics?

A

Extra-pyramidal dose dependent side effects which includes:
Akathisia
Dystonia
Tardive dyskinesia
Parkinsonism

In addition to other side effects:
Anticholinergic
Cardiac
Hyperprolactinaemia
Sexual dysfunction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the general advantages of using depots?

A

Can quickly identify non-adherence - Doctor can be informed immediately when a patient has missed a dose
Good for patients who struggle with adherence
Good for patients who don’t want to take tablets every day
Ensures the patient is always receiving a therapeutic effect from their medication regardless of their state of mind
More consistent plasma levels - less side effects
Remains 1-2 weeks after a missed dose
Avoids first pass metabolism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are the general disadvantages of using depots?

A

Can be painful, uncomfortable, produce injection site reactions
Oral to long acting injections can be complicated
Stigma
Preparations require mixing/refrigeration
Dosing titration may be more difficult than with oral
ADRs persist for longer
Poor injection technique

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are some of the general principles of prescribing anti-psychotics?

A

Use the lowest effective dose as possible and any dose increases should not occur within 1-2 weeks to see a full therapeutic effect
Use a single anti-psychotic when possible due to the increased risk of adverse effects
Only use combinations when a single anti-psychotic is inadequate
Antipsychotics should not be prescribed as when necessary for sedative effect
Assess response using rating scales and document outcome in patients records
Reduce dose gradually to prevent withdrawal and symptom rebound

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How is high dose anti-psychotic classified?

A

As single dose therapy above the BNF maximum or two or more antipsychotics prescribed concurrently that, when expressed as a percentage of their maximum daily dose total more than 100%.
This includes PRN use.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Does using two anti-psychotics equate to greater effectiveness?

A

No there is nothing to suggest anti-psychotic polypharmacy leads to greater effectiveness.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

If high dose anti-psychotic therapy is used what needs to be monitored?

A

Target symptoms
Therapeutic response
Side effects with close physical monitoring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

When is rapid tranquiliser used?

A

It is used to:
Reduce patient suffering
Reduce risk of harm by others
To do harm by prescribing safe regimens and monitoring physical health

It can only be used once verbal de-escalation has failed and oral medication has been refused.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Which medications can be used for rapid tranquilisation?

A

IM Lorazepam, or IM Haloperidol with IM Promethazine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is the monitoring required for rapid tranquilisation?

A

Bp
Temperature
Respiratory rate
Consciousness

Should be done hourly or every 15 minutes if the BNF maximum was exceeded or additional concerns were raised.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How is treatment resistant psychosis defined?

A

Lack of satisfactory improvement despite use of at least two different anti-psychotic drugs including a SGA prescribed for at least 4-6 week trial period.
This affects 1/3 of patients using anti-psychotics.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Which anti-psychotic is licensed for treatment resistant psychosis?

A

Clozapine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Explain how extra-pyramidal side effects occur with first generation anti-psychotics.

A

First generation anti-psychotics have a much greater affinity for the D2 receptor in comparison to second generation anti-psychotics. It is believed that Schizophrenia occurs due to dopamine hyperactivity at D2 receptors within the mesolimbic system causing the positive symptoms (responsible for the reward pathway).
First generation anti-psychotics were designed as D2 receptor antagonists with a clinical effect seen once 80% of D2 receptors within this pathway are occupied. However D2 antagonists are not specific to this one dopamine pathway, they also bind to D2 receptors within the other three pathways.
D2 antagonism within the nigrostriatal pathway leads to depleted dopamine leads to the extrapyramidal side effects as seen in the symptomatic presentation of Parkinson’s disease such as akathisia, dystonia, tardive dyskinesia.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the signs of dystonias?

A

Uncontrolled muscle spasms of the head and neck
Patients may also experience pain and stiffness
Eye rolling

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What are the risk factors for developing dystonia?

A

Occurs in 10% of patients those at a higher risk are:
Young men, those taking anti-psychotics for the first time, higher potency anti-psychotics

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

When are dystonia likely to occur?

A

Acutely within hours and even faster with IM
Tardive dystonia after months or years after taking the anti-psychotic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the appropriate management of dystonia?

A

Anticholinergics such as Procyclidine which can allow the patient to continue at the effective dose
Switching to a SGA
Reducing the dose of anti-psychotic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are some of the signs and symptoms of Parkinsonism?

A

Tremours
Rigidity
Bradykinesia - reduced facial expression, slow body movements, inability to initiate movement, speaking with a flat monotone voice

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Which patients are more likely to experience Parkinsonism and when does it occur?
Elderly females, those with pre-existing neurological damage Days to weeks of initiation or following a dose increase
26
What is the appropriate management of anti-psychotic induced Parkinsonism?
Using anticholinergics (Procyclidine again) Dose reduction Switching to one with less EPSEs such as SGA
27
How does Akathisia present?
As an inner restlessness including pacing or a shaking leg
28
Which patients are more likely to experience Akathisia and when does it occur?
25% of those taking FGAs will experience it acutely and it is common when starting Aripiprazole. Can occur within hours or days of starting the anti-psychotic/increasing the dose and can persist for months.
29
What is the appropriate management of akathisia?
Reducing the dose Using an alternative - SGA Short course of Benzodiazepines such as Lorazepam when starting the anti-psychotic
30
What are some of the signs and symptoms of tardive dyskinesia?
Lip smacking, blinking, upper body movements and choreiform hand movements (such as playing the piano).
31
Which patients are more likely to experience tardive dyskinesia and when does it occur?
Older age, affective illness, Schizophrenia, high doses of anti-psychotics, acute EPSEs in early treatment. Can take months to years to develop
32
What is the appropriate treatment for tardive dyskinesias?
Stop all anticholinergics Reduce dose or switch, Quetiapine and Clozapine are good
33
Explain how hyperprolactinaemia occurs with anti-psychotics (particularly first generation).
As mentioned previously anti-psychotics particularly first generation due to their higher affinity for D2 receptors, also antagonises D2 receptors within pathways other than the mesolimbic pathway. D2 antagonism within the tuberohypophyseal extends from the pituitary to the hypothalamus. Dopamine within this pathway inhibits the release of prolactin, a hormone responsible for lactation. Therefore by depleting dopamine levels within this pathway by the administration of anti-psychotics this then results in hyperprolactinaemia as the inhibitory neurotransmitter is reduced so prolactin secretion is increased.
34
What is the symptomatic presentation of hyperprolactinaemia?
Persistent elevation can cause suppression of the hypothalamic pituitary - Sexual dysfunction - Menstrual disturbances - Breast growth and galactorrhoea (breasts leak milk) - May include delusions of pregnancy
35
What are some of the longer term complications associated with hyperprolactinaemia?
Reduction in bone mineral density Increased risk of breast cancer
36
What is the appropriate management for hyperprolactinaemia?
Reduction of dose Switch to a prolactin sparing anti-psychotic Adding a low dose Aripiprazole (has antagonist activity at 5-HT2A resulting in decreased prolactin secretion).
37
Explain the rationale for the development of the second generation anti-psychotics.
The second generation anti-psychotics were designed to reduce the extra-pyramidal and hyperprolactinaemia seen in the first generation anti-psychotics. Second generation anti-psychotics antagonise 5-HT 2A receptors which cause an increase of dopamine at the striatum (nigrostriatal pathway) resulting in reduced extra-pyramidal side effects and counteracting the induced effects of D2 antagonism. Also 5-HT2A receptors inhibit the release of 5-HT, usually 5-HT increases prolactin secretion therefore by inhibiting this receptor this should reduce prolactin secretion and hence hopefully reduce hyperprolactinaemia and associated effects.
38
What are the main side effects associated with the second generation anti-psychotics?
Metabolic side effects (syndrome): Weight gain Hyperglycaemia Hyperlipidaemia In addition to other side effects: Anticholinergic Cardiac Hyperprolactinaemia Sexual dysfunction
39
What is some of the monitoring required for second generation anti-psychotics?
At baseline: Waist circumference Blood glucose (fasting) Weight HbA1c Non-fasting blood lipids Blood pressure U&Es This should be repeated at 12 weeks and then annually (every 3 months for the first year with Clozapine and Olanzapine). Weights should be taken weekly for the first six weeks and then at 3 months, 12 months and then annually.
40
Which medications are most likely to cause sexual dysfunctions?
Risperidone and Haloperidol Least likely with Aripiprazole and Quetiapine
41
What is the appropriate management of sexual dysfunctions?
Identify a cause before treating Monitor prolactin levels Consider the potential for spontaneous reduction Adjust, omit of a single daily dose (measure trough levels) 3-6mg Aripiprazole Sildenafil - specified circumstances Consider urology referral if there appears to be an unidentified cause
42
Affinity to which receptors causes sedation?
Dopaminergic, histaminic or adrenergic receptors
43
Why can sedation be at times beneficial?
Can help to reduce agitation in psychosis
44
What is the appropriate management for sedation?
Risk reduction and management is central to management of sedation: Review concurrent medications Start at a low dose Counsel patients on driving Sedative effects are usually short term Could trial a dose of reduction Consider switching anti-psychotics Consider prescribing at night or giving a bigger dose then Avoid psychostimulants like modafinil (which also interacts with Clozapine)
45
What are the antihistaminic side effects?
Sedation Dizziness Blurred vision Anxiety Increased appetite leading to weight gain GI - constipation, diarrhoea Insomnia Infrequent adverse effects: Urinary retention Palpitations Hypotension Headache Hallucination Psychosis Erectile dysfunction
46
Which anti-psychotics have affinity to H1 and therefore have antihistaminic side effects?
Highest affinity: Chlorpromazine Clozapine Levomepromazine Olanzapine Quetiapine
47
What are the anticholinergic side effects?
Cognitive impairment Delirium Hypothermia Confusion Dry mouth Constipation Blurred vision Glaucoma Urinary retention Tachycardia
48
Which anti-psychotics have affinity to M1 and therefore have anticholinergic side effects?
Highest affinity: Clozapine Levomepromazine Olanzapine Quetiapine?
49
What is the most appropriate management of anticholinergic side effects associated with anti-psychotic use?
Identify patients with a pre-existing medical condition which may contraindicate their use to the anticholinergic side effects of anti-psychotics. Review concurrent medications- minimalise anticholinergic burden Start low, go slow Trial a dose reduction Switch
50
What are adrenergic alpha-1 antagonism mediated side effects?
Dizziness Orthostatic/Postural hypotension Reflex tachycardia
51
Why are patients with Schizophrenia at a 2-3x risk of death of CVD?
Smoking Poor lifestyle - poor self-care, lack of exercise Substance misuse FGA/SGA
52
Which anti-psychotics have affinity to a1 and therefore have anti-adrenergic side effects?
Highest affinity: Chlorpromazine Clozapine Haloperidol Levomepromazine Olanzapine Paliperidone Quetiapine Risperidone
53
What are some of the more severe cardiac side effects?
This is associated with sudden cardiac death and include: Ventricular tachycardia Torsade des pointes Delayed myocardial repolarisation Myocarditis Cardiomyopathy
54
What is the baseline cardiac monitoring for anti-psychotics?
At baseline: Bp Pulse Possible ECG This should be repeated at 12 weeks and then annually
55
What is the appropriate management for managing the cardiac side effects of anti-psychotics?
Ensure gradual titration as effects are seen more at the beginning and following rapid dose titrations Consider a dose reduction Co-prescribing medications to reduce heart rate Reviewing if the patient is taking other medications which cause QT prolongation Switch If myocarditis is suspected STOP and refer to cardiology
56
What are some of the CVD risks associated with Clozapine?
Thromboembolism Myocarditis - first 6-8 weeks Cardiomyopathy - peaks at 9 months
57
What are the serotonin mediated side effects?
Weight gain (5-HT2c and 5-HT1) and increased appetite
58
Which receptors does Clozapine have affinity for?
Weak D2 receptor antagonist Strong action at 5-HT2A Anticholinergic Antihistaminic alpha-1 antagonist
59
What is the main side effect of Clozapine and how is it managed?
Risk of agranulocytosis or neutropenia Patients have to have regular blood monitoring before starting treatment, weekly for first 18 weeks, fortnightly until a year and then monthly Medication can only be supplied if bloods have been checked.
60
What are the different scales of Clozapine blood monitoring to manage against agranulocytosis and neutropenia?
Green: WBC above or equal to 3500/mm3 and ANC above or equal to 2000/mm3 - Can be supplied Amber: WBC at 3500-3000/mm3 and ANC at 1500-2000/mm3 - Monitoring increased to twice weekly but can be supplied Red: WBC below 3000/mm3 and ANC below 1500/mm3 - STOP immediately and start daily bloods
61
How can agranulocytosis be avoided?
Gradually up-titrating the medication as agranulocytosis is associated with increased dosing.
62
What are some of the GI side effects associated with Clozapine?
Mainly Constipation but can also cause Nausea and vomiting Dyspepsia These are due to anticholinergic, antihistaminic and antagonism of 5-HT receptors
63
What can exacerbate Clozapine induced constipation?
Other medications having similar effects Dehydration Immobility
64
What is the appropriate management for Clozapine induced constipation?
Dietary advice, fluid, fibres, exercise Laxatives either stimulant, stool softeners or osmotic Avoid
65
When and why does Clozapine induced hypersalivation occur?
Dose dependent hypersalivation occurs due M4 or alpha-2 antagonism with impaired swallowing reflex leading to dribbling/drooling but can also cause life threatening aspiration pneumonia. Usually occurs at the beginning of treatment and may improve over time.
66
What is the appropriate management of aspiration pneumonia?
No licensed treatment Dose reduction or switching may improve side effect however if the patient is already taking Clozapine - they may not work for their positive symptoms Could use an antimuscarinic such as Hyoscine Hydrobromide but can then cause constipation Chewing gum Towel on pillow
67
What are some of the signs and symptoms of neuroleptic malignant syndrome?
Fever Diaphoresis Muscle rigidity Alteration in mental state Tachycardia Tremor Incontinence Elevated creatine kinase, Leucocytosis, altered LFTs
68
What are the risk factors for neuroleptic malignant syndrome?
Male Younger age Dehydrated Alcoholic Hyperthyroidism Parkinson's Psychomotor agitation High potency FGAs Recent rapid dose increases or reduction Abrupt withdrawal Antipsychotic polypharmacy
69
What is the appropriate management for neuroleptic malignant syndrome?
STOP anti-psychotics and monitor temperature, blood pressure and pulse Consider use of benzodiazepines Call an ambulance and transfer to hospital
70
What is the appropriate management following an episode of neuroleptic malignant syndrome?
Wait 5 days before restarting Use a low dose and increase very slowly and this should be a medication that is structurally unrelated and with lower dopamine affinity such as Quetiapine, Clozapine, Aripiprazole Avoid depots/LAIs
71
What are some of the pharmacodynamic interactions associated with anti-psychotics?
Anti-psychotic drugs can have an additive, synergistic or antagonistic effect, typically they interact with drugs also causing: QT prolongation Neutropenia/Agranulocytosis Increased sedation Increased anticholinergic side effects Decreased blood pressure/increasing risk of falls Increasing the risk of seizures Increased weight gain/metabolic changes
72
What are some of the pharmacokinetic interactions associated with anti-psychotics?
CYP enzyme inducers and inhibitors that can alter the metabolism and therefore exposure of many anti-psychotics that are metabolised through this route.
73
What is the interaction between Clozapine and smoking?
Tobacco smoke causes CYP 1A2 induction, which is one of the enzymes responsible for metabolising Clozapine. Cigarette smoking reduces plasma levels of Clozapine therefore by up to 50%.
74
What is the appropriate management of Clozapine if the patient is also a smoker?
If the patient is consistently smoking this isn't an issue however if they suddenly stop smoking for example get sectioned this can cause Clozapine levels to rise very quickly. Take plasma levels a week before and then a week after stopping Reduce dose gradual to 75% of the original If the patient restarts smoking an upward dose titration can occur to the original dose over a week
75
What are some of the other anti-psychotics that can also experience a reduction in plasma levels with smoking?
Olanzapine Haloperidol Zuclopenthixol Chlorpromazine Fluphenazine
76
What is the interaction between Clozapine and caffeine?
It inhibits CYP 450 1A2 causing an increase in Clozapine levels of up to 60% and also affects Olanzapine.
77
What is the appropriate management of anti-psychotics and caffeine?
Not an issue if both remain the same however additional monitoring is required if caffeine intake changes - this includes not just coffee but also fizzy and energy drinks and chocolate.
78
When do discontinuation symptoms occur?
From 4 days to 1-2 weeks
79
What are some of the discontinuation symptoms associated with anti-psychotic use?
Nausea and vomiting Seizures Anxiety Muscle pains Insomnia Dystonia Risk of psychosis reoccurring Anti-psychotics with significant anti-cholinergic effects may precipitate rebound
80
What are some of the prevention strategies to minimalize discontinuation symptoms?
Discontinue gradually and slowly Educate on potential withdrawal Most resolve spontaneously Short term benzodiazepines may help with anxiety and insomnia for example Anticholinergic drugs for cholinergic syndrome Original anti-psychotics can be restarted if bad/slower tapering of dose Cross taper when switching anti-psychotics