Schizophrenia Flashcards
List and describe the four dopaminergic pathways and if disrupted can cause?
Mesocortical pathway - underactivity causes negative Sx
Mesolimbic pathway - overactivity causes positive Sx
D2 antagonism of tuberfundibular pathway - hyperprolactinaemia
D2 antagonism of nigrostritial pathway - EPSE
What is the advice of the Royal College of Psychiatrists on doses of antipsychotic drugs above the BNF upper limit?
- Consider alternatives e.g. adjuvants, newer or 2nd gen
- Be aware of risk factors e.g. elderly, obesity
- Consider potential drug interactions
- ECG to exclude QT interval prolongation
- Increase dose slowly and once weekly
- Regular pulse, BP and temperature check
- Consider high-dose therapy for limited period only and review regularly. Stop if no improvement after 3 months
What to consider when administering antipsychotic drugs in an emergency?
IM dose should be lower than oral dose as avoids first-pass metabolism. Especially in active patients
Prescription should specify dose for each route
Review dose at least daily
What do consider when prescribing antipsychotics in elderly?
Small increased risk of stroke/TIA
Susceptible to postural hypotension and hyper/hypothermia
- Do not treat mild-moderate psychotic symptoms
- Initial dose should be half adult dose
- Review treatment regularly
What do consider when prescribing antipsychotics in patients with learning difficulties?
If patient not experiencing psychotic symptoms:
- Reduce dose or stop long-term antipsychotic treatment
- Review condition after dose reduced or if treatment stopped
- Refer to psychiatrist experienced in treating mental health problems in patients with LD
- Annual documentation of reasons for continuing antipsychotic prescription if dose not reduced/treatment discontinued
What side effects are first generation antipsychotics more likely to cause?
Hyperprolactinaemia and EPSE
What are the categories of first generation antipsychotics and specific side effects?
Group 1 (Phenothiazines): MOST SEDATIVE
- Chlorpromazine*
- Levomepromazine*
- Promazine*
Group 2: LEAST EPS
Pericyazine
Group 3: MOST EPS
- Fluphenazine*
- Perphenazine*
- Prochlorperazine*
- Trifluoroperazine*
Butyrophenones: MOST EPS
- Haloperidol (QT interval prolongation)*
- Benperidol*
Thiaxanthenes
- Flupentixol* (alerting effect so do not take in evening)
- Zuclopenthixol*
What is the difference in receptors antipsychotics block?
(1st vs 2nd gen)
1st gen = D2
2nd gen = D1-D4 and act on wide range of other receptors
What side effects do 2nd generation antipsychotics cause more?
Metabolic side effects
What are the 2nd generation antipsychotics?
Amisulpride
Aripiprazole
Clozapine
Olanzapine
Quetiapine
Risperidone
Which 2nd gen antipsychotics cause the most hypoprolactinaemia?
Risperidone and amisulpride
Which 2nd generation antipsychotic doesn’t cause hyperprolactinaemia and why?
Apiprazole - dopamine agonist
Which antipsychotics cause hyperglycaemia
Which antipsychotics cause most weight
- Risperidone, quetipaine, olanzapine, clozapine
- Olanzapine and clozapine
When are depot antipsychotics prescribed?
To aid compliance
What do depot antipsychotic preparations typically end in?
Deconate
When are depot preparations administered?
1-4 weeks IM
What do EPSE consist of?
ð Parkinsonian: Such a tremor, more common in the elderly. Anti-muscarinic drugs not indicated as they may worsen tardative dyskinesia
ð Dystonia: Abnormal face and body movements, more common in children and YA
ð Akathisa: Restlessness after large initial dosesdoses
ð Tardative dyskinesia: Involuntary jaw or face movements which develops on long term or high dose therapy. Elderly most common
Stop at first sign of fine vermicular movements of tongue
When do patients with schizophrenia have to be monitored?
Yearly physical health monitoring including CVS risk assessment
What are the side effects of antipsychotics?
Extrapyridamidal symptoms
Occurs more with 1st gen
Hyperprolactinaemia
More likely with riseridone, amisulpride and 1st gen
- Breast symptoms: enlargement, pain, glactorrhoea
- Reduced BMD
- Menstrual irregularities
- Sexual dysfunction/Reduced libido
Metabolic side effects
Occurs more with 2nd gen
- Hyperglycaemia and sometimes diabetes. Most with CiROQ
- Weight gain. Most with COW
- Lipid changes
Sexual dysfunction
Most with haloperidol and risperidone
Consider switching to alternative
Cardiovascular side effects
Tachycardia, arrhythmias and hypotension
QT interval prolongation
Hypotension and interference with temperature regulation
Elderly at risk of falls, hypothermia and hyperthermia
Neuroleptic malignant syndrome
Others:
Blood dyscrasias, drowsiness, photosensitivity at high doses, jaundice & antimuscarinic side effects
When to monitor prolactin levels
initial, 6 months and then yearly (and where clinically appropriate - APD that causes hyperprolactinaemia)
What is neuroleptic malignant syndrome? Treatment
Fatal condition reaction to antipsychotics
Muscle rigidity, fluctuating consciousness, hyperthermia and autonomic dysfunction with pallor, tachycardia, sweating, urinary incontinence and labile bp
Discontinue antipsychotic immediately
Can treat with bromocriptine or dantrolene
Lasts 5-7 days after stopping but longer with depot preparations
What antipsychotic prolongs the QT interval the most?
Pimozide + haloperidol + IV antipsychotics
Monitor ECG before treatment and yearly
Stop or reduce dose if occurs
Do not give concomitant drugs that prolong QT interval
Do not give concomitant drugs that cause electrolyte imbalance
What antipsychotics are hepatotoxic and cause acute dystonic reactions?
Phenothiazines
Monitoring requirements of antipsychotics
- Blood lipids and weight - before, 3 months and then yearly
- Fasting blood glucose - before, 6 months and then yearly
- FBC, LFTs, UeAs - before and then yearly
ECG and BP - before and after every dose titration
Are second gen antipyschotics more effective at treating pos or neg sx than first gen
Negative
What is the advice surrounding antipsychotics and sunlight?
As photosensitisation may occur with higher dosages, patients should avoid direct sunlight
In schizophrenia, are antipsychotics more effective on the negative or positive symptoms?
More effective on the positive symptoms
Which antipsychotics may need their dose adjusting according to smoking status during therapy?
Clozapine, Haloperidol, Chlorpromazine and Olanzapine
Which antipsychotic can cause contact sensitisation so should be handled with care?
Chlorpromazine tablets should NOT BE CRUSHED
What is the MHRA warning regarding prescribing antipsychotics in elderly patients with dementia?
Increased risk of stroke and a small increased risk of death If needed, use the lowest effective dose and for the shortest time
Review every 6 weeks
