Adverse effects Flashcards
What % of tardive dyskinesia cases are reversible?
Around 50%
Most common side effect of Valproate
Diarrhoea
Which TCA has the highest antihistaminergic activity?
Doxepin
Side effects of AChE inhibitors
GI - nausea, vomiting, diarrhoea, anorexia
Muscle cramps
Urinary incontinence
Donepezil associated with bradycardia
Which SSRI has the greatest risk of causing delayed ejculation and impotence?
Paroxetine
What is the commonest side effect of methylphenidate?
Insomnia
What % of patients develop tardive dyskinesia?
5%
Blockade of which receptors leads to postural hypotension
Alpha-1
When treating serotonin syndrome, antagonism of which receptor is useful for controlling neurological signs?
5-HT2A
What is the CATIE study?
Clinical Antipsychtoic Trials of Intervention Effectiveness
What were some of the outcomes from CATIE?
Irrespective of prescribed drug, 74% discontinued treatment in 18 months
Olanzapine had the lowest discontinuation rate - 64% but highest side effect burden
First generation drugs do as well as second
Haloperidol was not included in the trial
Quetiapine group had less EPSEs
When is the maximum risk of Ebstein anomaly when taking lithium seen?
Maximum risk 2-6 weeks after conception
The toxic confusional state caused by antipsychotics is mainly due to which receptor?
Muscarinic receptor blockade
Which benzo is most toxic?
Alprazolam
Incidence of NMS
0.07-0.2%
What are some possible treatment options for Clozapine induced hypersalivation?
Anticholinergics - amitriptyline Benzatropine Trihexyphenidyl Hyoscine Pirenzepine Clonidine has also been used
Medications to treat akathisia
Propranolol Clonazepam Mirtazapine Anticholinergics Low evidence for clonidine
Which class of antidepressant should be avoided in people who do not want to gain weight?
Tricyclics
Which drug can cause nephrolithiasis?
Topiramate
Risk factors for tardive dyskinesia
- Chronic use of antipsychotics
- Cessation of chronic treatment
- Concomitant anticholinergic treatment
- Elderly
- Female
- Organic disorder
- Previous head injury
- Alcoholism
- Comorbid mood disorder
- Negative symptoms of schizophrenia
- DM
What is the risk of developing fatal agranulocytosis with clozapine?
1 in 4250 but less than 1 in 8000 with standard monitoring
Which drug is licensed for treatment of tardive dyskinesia in the UK?
Tetrabenazine
Sexual side effects of SSRIs are due to the stimulation of which receptors?
5HT2
Lithium induced hypothyroidism is more common in which group?
Young females
Which diuretic can be used to treat lithium induced poyuria without causing lithium toxicity?
Amiloride
Reflexes in NMS vs serotonin syndrome
NMS - bradyreflexia
Serotonin syndrome - hyperreflexia/clonus
Lab findings in NMS vs serotonin syndrome
NMS - high WCC, high CK
Serotonin syndrome - no leucocytosis, CK normal
In overdose, how do TCAs cause death?
Myocardial sodium channel blockade leading to intraventricular conduction delays, ventricular dysrhythmias, decreased CO and hypotension
How should you treat a MAO induced hypertensive crisis?
Alpha-adrenergic antagonists - phentolamine or chlorpromazine
Moclobemide MOA
Reversible MAO inhibitor
Which SSRI has the highest level in breast milk?
Fluoxetine
Upper limit of QTc for men
440
Which other antiepileptic can cause steven-johnsons?
Carbamazepine
MOA Ramelteon
MT1/MT2 receptor agonist
MOA atomoxetine
Selective noradrenaline reuptake inhibitor
How long does it generally take for tardive dyskinesia to appear?
Usually after 1-2 years of treatment
What is tardive dyskinesia?
Abnormal, involuntary movements of muscles of head, limbs and trunk
Perioral movements are most common
When is TD absent?
When sleeping
Do patients have insight about TD?
No
How can you manage tardive dyskinesia?
Most cases remit spontaneously
Clozapine can reduce risk and also treat TD
Adding clonazepam can be considered
Why do you get priapsm?
Alpha-1 blockade and anticholinergic activity
What can be used to treat sexual dysfunction in men that is associated with hyperprolactinaemia?
Bromocriptine
What effect can long term chlorpromazine have on skin?
Blue-gray discolouration in skin exposed to sunlight
What eye problems are associated with high doses of thioridazine?
Irreversible retinal pigmentation
What eye problems are associated with high doses of chlorpromazine?
Pigmentation of anterior lens and posterior cornea - benign and not vision impairing
What is chlorpromazine associated with in first month of treatment?
Cholestatic jaundice with rash and eosionophilia - recommended to stop and avoid in future
Which TCA is most selective of serotonergic reuptake?
Clomipramine
Which TCS is most selective for noradrenaline reuptake?
Desipramine
Which TCA has the most antihistaminic activity?
Doxepin
Management of serotonin syndrome
Withdraw offending agent
Supportive care
Benzo
5HT2A antagonists - cyproheptadine, atypical antipsychotics, chlorpromazine
Gynae effect of fluoxetine
Can change duration of menstrual cycle
Haematological effect of SSRIs
Can cause functional impairment of platelet aggregation but not a reduction in platelet numbers
Effect of buspirone on haloperidol concentrations
Increases haloperidol levels
Cardiac effects of lithium
ECG with therapeutic lithium doses similar to hypokalaemia - flat/inverted T waves
Effect of lithium on sinus node
Can depress sinus node so contraindicated in sick sinus syndrome
Which group of patients are at higher risk of lithium?
Pre-existing antithyroid antibodies
Young women
Rapid cycling patients
Which gynae problem can valproate cause?
Polycystic ovaries
Which blood finding can valproate cause?
5 to 40% of people experience a persistent elevation in liver transaminases up to 3x the upper limit of normal - resolves after discontinuing drug
Most common teratogenic effects of valproate
Ebstein’s anomaly - 20x risk of general pop
LD and low IQ in children
Why is tacrine not used in uk anymore?
Fatal hepatotoxicity
Which receptor does zopiclone act on?
Alpha-1 subunit on omega-1 receptor
Best antipsychotic if patient has hyponatraemia
Clozapine
Which antidepressant is less likely to cause a switch to mania?
Buproprion
Which scan can show loss of dopaminergic neurons?
DAT scan
Serious Side effects of cholinesterase inhibitors
- Increase GI bleeding risk
- Bradycardia
- COPD exacerbation
- Urinary retention
- Increased seizure risk
How is memantine metabolised?
Excreted unchanged in urine
Does Rivastigmine’s metabolism rely on liver enzymes?
No
Unique side effect of eszopiclone
unpleasant taste
What does the black triangle symbol?
Drug is newly licensed and requires additional monitoring