Switching_Antidepressants_Flashcards
What should be done when switching from citalopram, escitalopram, sertraline, or paroxetine to another SSRI?
The first SSRI should be withdrawn before the alternative SSRI is started.
What is the process for switching from fluoxetine to another SSRI?
Withdraw fluoxetine, then leave a gap of 4-7 days before starting a low-dose of the alternative SSRI.
What is the recommended method for switching from a SSRI to a tricyclic antidepressant (TCA)?
Cross-tapering is recommended, where the current drug dose is reduced slowly while the dose of the new drug is increased slowly.
What is the exception when switching from a SSRI to a TCA?
Fluoxetine should be withdrawn prior to starting TCAs.
What is the process for switching from citalopram, escitalopram, sertraline, or paroxetine to venlafaxine?
Cross-taper cautiously. Start venlafaxine at 37.5 mg daily and increase very slowly.
What is the process for switching from fluoxetine to venlafaxine?
Withdraw fluoxetine, then start venlafaxine at 37.5 mg each day and increase very slowly.
What does it mean to withdraw an SSRI?
Withdrawing an SSRI means gradually reducing the dose and then stopping it.
summarise switching antidepressants
Depression: switching antidepressants
The following is based on the Clinical Knowledge Summaries depression guidelines, which in turn are based on the Maudsley hospital guidelines.
Switching from citalopram, escitalopram, sertraline, or paroxetine to another SSRI
the first SSRI should be withdrawn* before the alternative SSRI is started
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
Switching from a SSRI to a tricyclic antidepressant (TCA)
cross-tapering is recommend (the current drug dose is reduced slowly, whilst the dose of the new drug is increased slowly)
- an exceptions is fluoxetine which should be withdrawn prior to TCAs being started
Switching from citalopram, escitalopram, sertraline, or paroxetine to venlafaxine
cross-taper cautiously. Start venlafaxine 37.5 mg daily and increase very slowly
Switching from fluoxetine to venlafaxine
withdraw and then start venlafaxine at 37.5 mg each day and increase very slowly
*this means gradually reduce the dose then stop
A 32-year-old man with a longstanding moderate depression comes to see his GP after recently being started on a new medication by his psychiatrist. He complains that his appetite has increased hugely and as a result he has put on a significant amount of weight. He is also constantly tired and is struggling to concentrate at work.
Which of the following medications has most likely been started?
Sertraline
Mirtazapine
Lithium
Carbamazepine
Selegiline
Mirtazapine
If a patient is unresponsive to initial treatments for depression or experiences side effects to their current medication, it is not uncommon for them to be switched to a different antidepressant. In this case it would not be unreasonable to assume that the patient had been tried on a selective serotonin reuptake inhibitor previously and therefore sertraline can be excluded.
Lithium and carbamazepine are advanced treatments for serious mood disorders and therefore unlikely in this case, which leaves Selegiline and mirtazapine.
Selegiline is a monoamine oxidase inhibitor which are an older class of antidepressant which have been largely phased out due to their side effects which leaves mirtazapine as the most likely answer.
Some of the most potent side effects of mirtazapine are a large increase in appetite (and subsequent weight gain) and drowsiness. These side effects are so pronounced that mirtazapine has been known to be used as an appetite stimulant and sleep aid off-formulary.
