Pharmacological treatment of psychotic disorders Flashcards
Which conditions often warrant use of antipsychotics?`
Schizophrenia Schizoaffective disorder Bipolar disorder Psychotic depression Augmenting agent in treating resistant depressive or anxiety disorder
Which pathways in the brain are affected by dopamine?
Mesocortical
Mesolimbic
Nigrostriatal
How is the mesocortical pathway involved in psychosis?
Negative disorders
Cognitive disorders
Problem here in psychotic patients is too little dopamine
How is the mesolimbic pathway involved in psychosis?
Positive symptoms
Problem here in a psychotic patient is too much dopamine
How is the nigrostriatal pathway involved in psychosis?
Movement regulation
Dopamine hypoactivity in this pathway leads to Parkinsonian movements
Bradykinesia, rigidity, tremors, akathisia, dystonia
How is the tuberoinfundibular pathway involved in psychosis management?
Dopamine inhibits/regulates prolactin release
Blocking dopamine in this pathway will predispose the patient to hyperprolactinaemia
How does hyperprolactinaemia present?
Gynecomastia
Galactorrhoea
Decreased libido
Menstrual dysfunction
How do typical antipsychotics work?
D2 dopamine receptor antagonists
High affinity
What is a consequence of the high affinity of high potency D2 antagonist antipsychotics?
Extrapyramidal side effects like Parkinsonian movements
What are atypical antipsychotics?
Serotonin-dopamine 2 antagonists (SDAs)
Considered atypical for affect dopamine and serotonin neurotransmission
What is risperidone?
Atypical antipsychotic
Likely to induce hyperprolactinaemia
Weight gain and sedation
Monthly IM
What are some drawbacks of the atypical antipsychotic olanzipine?
Weight gain
Raised glyceride, cholesterol, glucose
Hyperprolactinaemia
Acute dystonic reaction including oculogyric crisis
What are some pros of the atypical antipsychotic olanzipine?
Use as immediate release IM good for compulsory medication
Also comes in regular tabs
What are some drawbacks of the atypical antipsychotic quetiapine?
Abnormal LFTs
Weight gain
Raised cholesterol, triglyceride, glucose
Orthostatic hypotension
What are some pros of quetiapine?
Sedative effect useful for conjunctive treatment for depression (sleep) or schizophrenia
What are some pros of aripiprazole?
Available as regular tab or immediate release IM
No QT prolongation
Not associated with weight gain
Lower incidence of extrapyramidal side effect
Why does aripiprazole have a lower incidence of extrapyramidal side effects?
Mechanism of action as a D2 partial agonist results in balancing dopamine deficiencies
What are some drawbacks of aripiprazole?
Interactions with fluoxetine and paroxetine
Could cause intolerability due to akathisia/activation
What is a good atypical antipsychotic option for treatment resistant patients?
Clozapine
Generally reserved for resistant patients due to side effects
What are some side effects of clozapine?
Agranulocytosis Increased risk of seizures Sedation Weight gain Abnormal LFTs Hyperosmolar coma Raised cholesterol, glucose, triglyceride
Why do patients on clozapine have to get weekly blood tests?
Agranulocytosis may lead to death
Blood test will show any reduction in neutrophils
What is Tardive Dyskinesia (TD)?
Involuntary muscle movements that may not resolve with drug discontinuation
What is neuroleptic malignant syndrome (NMS)?
Severe muscle rigidity Fever Altered mental status Autonomic instability Elevated WBC Abnormal LFTs Potentially fatal
How are extra pyramidal side effects managed?
Reduce dose if possible
Anticholinergics like benztropine
Dopamine facilitators like amantadine
Propanolol
What are some associations of a 3rd episode of schizophrenia?
Clear link to reduced functioning, lower IQ, negative symptoms
Consider long acting IM
What are some tests to run before commencing on antipsychotics?
LFT
Fasting lipid profile
Fasting blood sugar
CBC
Which conditions are benzodiazepines used for?
Insomnia
Parasomnias
Anxiety disorders
CNS depressant withdrawal protocols
What are some side effects of benzodiazepines?
Somnolence Cognitive deficits Amnesia Disinhibition Tolerance Dependence
What is another name for diazepam?
Valium
How do we avoid benzodiazepine dependence?
Treat underlying cause
Reserve for short term uses like sedation or withdrawal states
What would be a good treatment option for non-compliant patients suffering from schizophrenia or other psychotic disorders?
Depot antipsychotic
IM injection every 2-4 weeks
What is involved in the acute phase of bipolar disorder treatment?
Stop any antidepressants
Start antipsychotic, lithium or mood stabiliser
Consider adding short term benzodiazepine
Combine antipsychotic and lithium if response is inadequate
What is involved in the management phase of bipolar disorder?
Lithium/olanzapine/valproate/quetiapine for at least 2 years
Antidepressants/CBT for intercurrent depression
Combine mood stabilisers for rapid cycling conditions
What is acute dystonic reaction?
Involuntary contractions of muscles of the extremities, face, neck, abdomen, pelvis, or larynx in either sustained or intermittent patterns that lead to abnormal movements or postures
Oculogyric crisis
What effect does dopamine have on prolactin release and how might this be clinically relevant?
Dopamine inhibits prolactin release
Typical antipsychotics inhibit dopamine receptors
This may cause galactorrhoea
