Antipsychotics review article Flashcards
Extrapyramidal side effects caused by the first available antipsychotics consisted of
Parkinsonian symptoms: tremor, rigidity, bradykinesia and stooping gait.
Acute dystonic reactions (abnormal face and body movements)
Akathisia (inner restlessness)
Tardive dyskinesia (rhythmic, involuntary movements of tongue, face and jaw)
What limits the use of clozapine?
Blood disorders
Antipsychotics developed after clozapine are termed:
atypical, the older ones are classed as typical.
It is generally accepted that when used at a therapeutic dose atypical antipsychotics tend not to cause what?
EPSE or disturbed prolactin regulation.
Exceptions being: risperidone, amisulpride.
Which two atypical antipsychotics can cause EPSE or disturbed prolactin regulation?
Risperidone
Amisulpride.
All current antipsychotics, with the exception of _________, antagnoise __________ __________ (__); this is hypothesised to be their main mode of action.
Aripiprazole, dopamine receptors (D2)
What are the predictable side effects of most of the existing antipsychotic agents?
Sedation (histamine blockade)
Dry mouth, blurred vision, constipation, urinary retention (cholinergic blockade)
Postural hypotension, dizziness, syncope (alpha antagonism)
The sedation caused by antipsychotics is due to _________ _________
Histmaine blockade
The dry mouth, blurred vision, constipation and urinary retention caused by antipsychotics is due to __________ _______
Cholinergic blockade
The postural hypotension, dizziness, syncope etc caused by antipsychotics is due to:
Alpha antagonism
It is now thought that the antipsychotic activity of the agents may be due to the ratio of activity at __/___ receptors and that ________ may also be involved.
D2/5HT2a
Glutamate.
All atypical agents, except amisulpride, also antagonise 5HT in a varying but greater degree in proportion to D2 antagonism.
Why has aripiprazole been described as a third generation antipsychotic with a unique mode of action?
It acts as a potent partial agonist at D2 dopamine and 5HT1a serotonin receptors. AND as an antagonist at 5HT2a serotonin receptors.
Despite this it has been found by a Cochrane review to be equally effective as typical and atypical agents.
In recent years, the atypical agents olanzapine, risperidone and quetiapine have become what?
The most presribed agents of choice.
The choice of an antipsychotic should always be based on what?
The patients previous response to treatment, past experiences (S/Es) and preference as well as any concurrent medical co-morbiditiy and medication.
An atypical agent should be considered for people who have an existing diagnosis of schizophrenia who are what?
Already prescribed a typical agent but are experiencing intolerable side-effects, such as EPSE.
Are there specific guidelines as to which agent to use?
No.
For what patients may a ‘depot’ intramuscular formulation be an appropriate maintenance treatment?
Forget to take medication
Problems with swallowing.
Don’t like having to take oral medications.
Despite greater efficacy in treating both normal and treatment resistant schizophrenia, why is clozapine not first line?
It can cause neutropenia followed by agrunlocytocis, which if left unchecked can be fatal.
Can only be used by HCP and patients registered with a clozapine monitoring agency; where regular (initially weekly) FBC tests are mandatory.
What is metabolic syndrome?
A cluster of abnormalities that increase the risk of cardiovascular disease, namely: obesity, hyperlipidaemia, hypertension, hyperglycaemia.
Linked to use of antipsychotics which can cause weight gain - mostly during first 3-4 months of starting a new antipsychotic which can be an issue in those who frequently change etc.
Which agents tend to cause a high risk of disturbing the lipid balance potential?
Clozapine
Olanzapine
Moderate risk:
Quetiapine
Minimal risk:
Risperidone
What is Neuroleptic malignant syndrome?
Rare
Life threatening
Caused by any antipsychotic, thought to be due to over-blockade of the dopaminergic system.
Treatment should not be recommenced until after a week and then with caution.
All antipsychotics have what effect on antiepileptic agents?
Have the potential to antagonise their anticonvulant effects.
What impact do antipsychotics have on the body response to alcohol, anxiolytics and hypnotics, opioid agents and the effects of barbiturates?
Enhance
Why is lithium and antipsychotic use of concern?
Increased CNS toxicity.
