Selective serotonin reuptake inhibitors Flashcards
What is the class of drug that is considered first line in the treatment of depression?
Selective serotonin reuptake inhibitors (SSRI)
What are the two preferred selective serotonin reuptake inhibitors (SSRIs) as first line in the treatment of depression?
Sertraline (in Notts - cheapest)
Fluoxetine
Citalopram
What is the selective serotonin reuptake inhibitor (SSRI) that is first line in the management of depression post myocardial infarction?
Sertraline
What are the common side effect of SSRIs?
Gastrointestinal symptoms including GI bleeding - most common
Increased anxiety, insomnia and agitation after starting SSRI
Which class of drug increases the likelihood of GI bleeding in a patient on SSRIs?
NSAIDs
Which class of drug should be prescribed to patient on SSRIs if they are also taking NSAIDs?
Proton pump inhibitors - eg omeprazole
Which two SSRIs have the highest propensity for drug interactions?
Fluoxetine
Paroxetine
Which SSRIs are particularly associated with QT interval prolongation?
Citalopram
Escitalopram
In which patients should citalopram be avoided?
Those who:
Have congenital long QT syndrome
Have pre-existing QT interval prolongation
Are currently on other medications that prolong QT interval
Other than citalopram and escitalopram, what commonly prescribed drugs are known to prolong QT interval?
Class 3 antiarrhythmics - Amiodarone and sotalol
Class 1a antiarrhythmics - Quinine and procainamide
Tricyclic antidepressants - Amitriptyline
Methadone
Chloroquine
Erythromycin
Haloperidol
Which SSRI should patients on antithrombotic agents such as warfarin or heparin be offered?
NICE guidelines recommends avoiding SSRIs in those patients on warfarin or heparin due to interactions. They should be offered mirtazapine instead (SNRI).
What are the drugs that should be avoided if possible if a patient is on SSRI, or conversely a patient being on which drugs may contraindicate starting them on a SSRI?
NSAIDs - avoid if possible or start on PPI
Warfarin/heparin - offer mirtazapine (SNRI) instead
Triptans - avoid SSRI
How long after starting a patient on a SSRI should the GP review them?
2 weeks - most patients
1 week - if under 30 or at an increased risk of suicide
If a patient has a good response to a SSRI, what is the minimum length of time that they should be continued on the medication to reduce chance of relapse?
6 months after remission
When stopping a SSRI, how should this be done?
Gradual dose reduction over a 4 week period
Which SSRI has a longer half life and therefore does not need gradual dose reduction over 4 weeks when stopping medication?
Fluoxetine
Which SSRI has the highest incidence of discontinuation symptoms?
Paroxetine
What are the discontinuation symptoms associated with SSRIs?
Increased mood change
Restlessness
Difficulty sleeping
Unsteadiness
Sweating
GI symptoms: pain, cramping, diarrhoea, vomiting
Paraesthesia
What is the name of the syndrome associated with SSRI overdose or toxicity?
Serotonin syndrome
What is serotonin syndrome?
A collection of symptoms that results from serotonin build up in the CNS, which usually results from an interactions between two drugs (often an SSRI and another antidepressant such as MOAI). Symptoms include restlessness, tremor, shivering, myoclonus, hyperreflexia, confusion, convulsions and possibly death.
What are the features of serotonin syndrome?
Restlessness
Tremor
Myoclonus
Hyperreflexia
Confusion
Convulsions
Hyperthermia
Shivering
Serotonin syndrome can be fatal
How do we treat someone with serotonin syndrome?
Stop drug
Monitor and manage hydration and haemodynamics with fluids
Symptomatic relief of agitation with benzodiazepines
Moderate: Cyproheptadine is a 5HT-2A antagonist which is useful in the acute patient.
Severe: need aggressive treatment and intensive care with early sedation, neuromuscular paralysis and ventilatory support.
A 54-year-old man attends his GP. He was started on fluoxetine eight weeks ago for depression and is now requesting to stop his medication as he feels so well. What should be recommended regarding his treatment?
It should be stopped straight away
It should be continued for at least another 6 weeks
It should be continued for at least another 3 months
It should be continued for at least another 6 months
It should be continued for at least another 12 months
It should be continued for at least another 6 months
This greatly reduces the risk of relapse. Patients should be reassured that antidepressants are not addictive.
A 25-year-old man comes for review of his depression. He has now been taking fluoxetine 20mg od for 4 weeks with no effect on his symptoms. It is decided to switch him to citalopram. How should this be done?
Withdraw fluoxetine with commencement of citalopram the next day
2 week period of overlapping the drugs
Wait 1 week after withdrawing fluoxetine before commencing citalopram
1 week period of overlapping the drugs
Wait 2 weeks after withdrawing fluoxetine before commencing citalopram
Wait 1 week after withdrawing fluoxetine before commencing citalopram
What are the guidelines regarding switching from a SSRI (apart from fluoxetine) to another SSRI?
The first SSRI should be withdrawn through gradual dose reduction before the alternative SSRI is started
What are the guidelines regarding switching from fluoxetine to another SSRI?
Withdraw then leave a gap of 4-7 days (as it has a long half-life) before starting a low-dose of the alternative SSRI
What are the guidelines regarding switching from a SSRI (apart from fluoxetine) to a tricyclic antidepressant?
Cross-tapering is recommended - the current drug dose is reduced slowly, whilst the dose of the new drug is increased slowly.
What are the guidelines regarding switching from fluoxetine to a tricyclic antidepressant?
Should be withdrawn prior to starting TCA
