Planning and agreeing an antidepressant switching strategy

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Guidance on planning and implementing the antidepressant switch after the need and choice of antidepressant have been decided.

Establish the need and what to switch to

Before you implement an antidepressant switch for the treatment of depression, you should establish the need for the switch and the antidepressant to switch to.

Planning the switch

Before undertaking the switch, you should plan, discuss, and agree a shared strategy and time scale with which to complete the process. Aspects to consider include:

Urgency of the switch

The urgency of the switch will affect the strategy followed. For people who are severely depressed and have failed to respond to antidepressant treatment or have experienced a severe or intolerable side effects, a fast switching strategy may be required. Where there is less urgency, a slower more cautious approach can be used. Abrupt withdrawal should be avoided unless there has been a serious side-effect.

Physical condition and co-morbidities

Older people and those with co-morbidities may be more susceptible to the additive effects of antidepressants so require caution when switching. People with complex medical and medication histories may be more susceptible to side-effects or medicines interactions.

Explaining the risks

Any antidepressant switch could be associated with risks, and whilst an appropriate strategy will help minimise these, they can never be eliminated completely. The person and/or carer should be aware of the risks associated with the switch and comfortable that the risk of not switching is greater than the risks associated with switching. Discontinuation symptoms and serotonin syndrome should both be explained so individuals know what to look out for and monitor.

Switching strategies

Different switching strategies exist although few studies have examined which is optimal. Choosing an appropriate strategy will depend on the type of antidepressants being switched, as well as the person’s symptoms which will guide the speed of the switch.

Below we’ve listed the approaches available. Specific recommendations for each individual switch are included in the individual articles listed below.

Cross-taper

Gradually reduce and stop the first antidepressant whilst simultaneously starting the second at a low dose and gradually increasing. Cross-tapering can usually be undertaken cautiously over 2 to 4 weeks, the speed is determined by individual tolerability. The Maudsley Prescribing Guidelines in Psychiatry provides  an example of a cross-tapering regimen shown in the table below.

Pre-switch dosage
Week 1
Week 2
Week 3
Week 4
Withdrawing citalopram
40mg daily 20mg daily 10mg daily 5mg daily 2.5mg daily
Introducing mirtazapine
Nil 15mg daily 30mg daily 30mg daily 40mg daily (if required)

Direct switch

Direct switches may be possible when antidepressants have similar pharmacology or mode of action. The second antidepressant should alleviate discontinuation symptoms of the first.

Stop the first antidepressant and start the second at the usual therapeutic dose the next day.

You may wish to consider a taper, stop and switch approach if the person is at a high risk of experiencing discontinuation symptoms.

Taper, stop and switch

Gradually reduce and then stop the first antidepressant; start the second immediately after stopping the first, usually on the next day.

Taper, washout and switch

Gradually reduce the dose of the first antidepressant and stop; wait for a period (the “washout”) before starting the second.

Stop, washout and switch

Stop the first antidepressant; wait for a period (the “washout”), before starting the second.

Providing a written summary

Once you have agreed your strategy for switching and everyone understands the actions, create a written summary explaining the rationale. Keep a copy in the medical record and give a copy to the person and/or carer too.

Monitoring people

During and after the switch, consider the monitoring that might be necessary.

Monitoring a person during and after antidepressant switching

Review people at appropriate time points; advise on what to expect and report; and beware of the possibility of discontinuation and serotonin syndromes.

Individual switches

We have advice on how to switch between individual antidepressants of different types. Browse our collection below.

Update history

  1. Link to NICE CKS removed and cross-tapering table added
  1. Published