Antidepressants Flashcards
SSRIs:
What are their indications?
First line for moderate to severe depression
Panic disorder
OCD
SSRI:
What is their mechanism of action?
They inhibit the reuptake of serotonin from the synaptic cleft
Thereby increasing availability for neurotransmission.
They have fewer side effects and less dangerous in overdose than TCA
SSRI:
What are common side effects?
GI upset
Weight/appetite loss/gain
Hypersensitivity reactions
Hyponaetremia: old people which may present as confusion and reduced consciousness
Suicidal thoughts and behaviour
Prolong QT INTERVAL
Increase risk of bleeding
Serotonin syndrome (if taken along side other serotonergic drugs -tramadol)
SSRI:
What can sudden withdrawal cause?
GI upset
Neurological and flu like symptoms
Sleep disturbances
SSRI:
What group of people would you need to take caution over
Epilepsy
Peptic ulcer disease
Young people (poor efficacy and increased risk of self harm and suicide)
Hepatic impairment
SSRI:
What are common interactions?
MAOI
Serotoninergic drugs
Bleeding risk if with anticoagulants, or NSAIDS
Drugs that prolong the QT interval
FOR ALL ANTIDEPRESSANTS:
When should symptoms be reviewed after starting?
How is it stopped and why?
How long should treatment last?
1-2 weeks after starting treatment and regularly after. If no effect is seen after 4 weeks consider changing dose or drug. Otherwise dose should be adjusted after 6-8 weeks
Gradually reduced over 4 weeks to minimise withdrawals and relapse
At least 6 months after resolution of symptoms and 2years for recurrent depression
SSRI:
What SSRI can be stopped abruptly?
Fluoxetine
SSRI
what’s an uncommon indication
Manage menopausal symptoms in women who have breast cancer that suppresses ovarian function
NOT-fluoxetine
Paroxetine
SNRI/tetracyclic antidepressants:
What are they indicated for?
major depression
GAD (venlafaxine, duloxetine)
diabetic neuropathy (duloxetine)
Duloxetine can also be used in neuropathic pain acts by increasing pre-synaptic conc in spinal inhibitory pathways.
SNRI/TETRACYCLINES :
What is its mechanism of action?
SNRI: interferes with uptake of serotonin-noradrenaline from synaptic cleft
Tetracyclic antidepressant:
antagonises inhibitory pre-synaptic alpha2-adrenorecptors.
Both increase monoamines for neurotransmission- improving mood and physical symptoms.
Tetracyclic AD:
MIRTAZAPINE
SNRI:
Venlafaxine, duloextine
SNRI:
What are common side effects and why?
Antimuscarinic side effects due to them being weak antagonists of muscurinic and histamine 1 receptors
tetracyclic ad: potent antagonist of histamine 1 receptors only
SNRI/TETRACYCLIC ANTIDEPRESSANTS:
What are important adverse events for both?
GI upset
dry mouth
neurological effects (Confusion, convulsions, abnormal dreams, headache, insomnia)
suicidal thoughts and behaviour
Less common:
hyPOnaetremia
SS
Sudden withdrawal can cause- neurological and flu like symptoms, GI upset and sleep disturbances
TETRACYCLIC AD:
What are side effects unique to it
bone marrow suppression
SNRI:
what are side effects unique to it?
can cause QT prolongation- increase risk of ventricular arrhythmias
greater risk of withdrawal effects
SNRI/TETRACYCLIC ANTIDEPRESSANTS:
What group of people would you be cautious in prescribing these classes?
Older people
renal impairment-dose reduction (duloxetine avoided in severe renal impairment)
risks of arrhythmias( venlafaxine avoided/caution)
SNRI/TETRACYCLIC ANTIDEPRESSANTS:
What are important interactions?
similar classes of AD that can increase risk of adverse reactions-
SS
SNRI/TETRACYCLIC ANTIDEPRESSANTS:
What is treatment dose of duloxetine for neuropathic pain?
duloxetine 60mg oral daily
TETRACYCLIC ANTIDEPRESSANTS:
When should mirtazipine be taken and why?
at night to avoid sedative effects
TETRACYCLIC ANTIDEPRESSANTS:
Why should a HCP be worried if a patient develops sore throat whilst on mirtazipine?
a symptoms of an infection could suggest bone marrow suppression.
TRICYCLIC ANTIDEPRESSANTS:
What are common indications?
Second line to moderate and severe depression
neuropathic pain
IBS- if antispasmodic
Migraine prophylaxis- amitriptyline
TRICYCLIC ANTIDEPRESSANTS:
What is their mechanism of action?
-inhibit serotonin and noradrenaline reuptake from synaptic cleft.
-Increase noradrenaline conc in descending spinal inhibitory pathways.
-Block muscarinic, histamine, alpha adrenergic, dopamine receptors- which is what causes adverse side effects.
TRICYCLIC ANTIDEPRESSANTS:
What are common side effects?
dry mouth
urinary retention
blurred vision
exacerbate cognitive impairment
sedation and hypotension- caused by blocked of histamine and adrenergic receptors
arrhythmias
ECG changes (QT prolongation and QRS duration)
seizures
hallucinations
mania
breast changes and sexual dysfunction, extrapyramidal effects ( blocking of D receptors)
TRICYCLIC ANTIDEPRESSANTS:
Why are they more dangerous than other AD in overdose?
Can cause life-threatening hypotension, arrhythmias, seizures, coma, respiratory failure
TRICYCLIC ANTIDEPRESSANTS:
Which patients need caution required on this medication
older people
epilepsy
CVD
Due to antimuscarinic effects may worsen- constipation, glaucoma, urinary symptoms die to prostate enlargement.
TRICYCLIC ANTIDEPRESSANTS:
What are important interactions?
MAOIs
Can cause antimuscarinic effects of other drugs.
TRICYCLIC ANTIDEPRESSANTS:
What are starting dosages for all indications.
Depression:
75mg daily
IBS/Neuropathic:
10mg daily
