Drugs in Psych Flashcards
Explain the mechanism of action, adverse effects and examples of typical antipsychotics
MoA - Dopamine D2 receptor anatagonist.
Adverse effects - Extrapyramidal side effects and hyperprolactinaemia.
Examples - Haloperidole or chlorpromazine.
Explain the mechanism of action, adverse effects and examples of atypical antipsychotics
MoA - Variety of receptors - D2, D3, D4, 5-HT.
Side effects - extrapyramidal side effects, hyperprolactinaemia, metabolic side effects.
Examples - Clozapine, risperidone, olanzapine.
What are examples of extrapyramidal side effects?
Parkinsonism,
Acute dystonia - sustained muscle contraction (managed with procyclidine)
Akathisia (restlessness),
Tardive dyskinesia (chewing and pouting, abnormal, involuntary movements)
Risks of using antipsychotics in elderly patients?
Increased risk of stroke and increased risk of VTE
Other side effects (non extrapyramidal)
Antimuscarinic (dry mouth, blurred vision, constipation, urinary retention).
Sedation,
Weight gain,
Raised prolactin,
Impaired glucose tolerance,
Neuroleptic malignant syndrome,
Reduced seizure threshold,
Prolonged QT interval (particular haloperidol)
Monitoring for antipsychotics
FBC, U&Es and LFTs
Lipids and weight,
Fasting blood glucose and prolactin,
BP
ECG (baseline)
CV risk assessment
Main adverse effects of atypical antipsychotics?
Weight gain,
Clozapine - agrangulocytosis,
Hyperprolactinaemia.
Examples of atypical antipsychotics
clozapine
olanzapine: higher risk of dyslipidemia and obesity
risperidone
quetiapine
amisulpride
aripiprazole: generally good side-effect profile, particularly for prolactin elevation
How should patients withdraw from benzodiazepines
Reduce by 1/8th of the daily dose every 2 weeks. If experiencing difficulty with this then switch to equivalent dose of diazepam and then reduce dose of diazepam by 2/2.5mg ever 2-3 weeks
Symptoms of benzodiazepines withdrawal syndrome?
insomnia
irritability
anxiety
tremor
loss of appetite
tinnitus
perspiration
perceptual disturbances
seizures
What are the adverse effects of clozapine?
Agranulocytosis,
Neutropenia,
Reduced seizure threshold,
Constipation,
Myocarditis,
Hypersalivation.
Dose adjustment needed is smoking
Features of Mirtazepine?
Antidepressant which blocks alpha2-adrenergic receptors.
Fewer side effects so useful in older people.
Two main side effects - increased appetite and sedation.
What are features of non-slective monoamine oxidase inhibitors?
Used in treatment of atypical depression and other psychiatric disorders.
Side effects - hypertensive reactions with tyramine containing foods and anticholinergic effects
What SSRI is most useful post MI?
Sertraline
SSRI in children and adolescents?
Fluoxetine
Adverse effects of SSRIs?
GI symptoms are most common.
Hyponatraemia
Increased risk of GI bleed.
May worsen anxiety and agitation
Interactions with SSRIs?
NSAIDs (if needed then coprescribe a PPI)
Warfarin/heparin (if needed then consider using mirtazapine),
Aspirin,
Triptans (increased risk of serotonin syndrome)
MOAIs (increased risk of serotonin syndrome).
Monitoring required with SSRIs?
Patients should be reviewed after two weeks unless under age 25 or at increased risk of suicide then these patients should be reviewed after 1 week.
If good response then patients should stay on treatment for 6 months after remission to prevent relapse
How to withdraw from SSRIs and potential discontinuation symptoms?
Gradual reduce over 4 week period (not required with fluoxetine)
Discontinuation symptoms: Increased mood change, restlessness, difficulty sleepying, unsteadiness, sweating, GI symptoms (pain, cramping, diarrhoea, vomiting), paraesthesia
SSRIs and pregnancy?
If used in first trimester there is increased risk of congenital heart defects.
If used in last trimester there is increased risk of persistent pulmonary hypertension.
Paroxetine has increased risk of congenital malformation.
Features of SNRIs?
Examples - duloxetine and venlafaxine.
Used to treat major depressive disorders, generalised anxiety disorder, social anxiety disorder, panic disorders and menopause.
What are the side effects of tricyclic antidepressants?
Drowsiness,
Dry mouth,
Blurred vision,
Constipation,
Urinary retention,
Postural hypotension,
Lengthening of QT inverval.
