Establish the need, what to switch to, and the strategy

Before you are able to monitor an antidepressant switch for the treatment of depression, you’ll need to establish the need for the switch, the medicine to switch to, and the strategy you’re following.

• Establishing if a person needs to switch their antidepressant
• Considerations when choosing an alternative antidepressant
• Planning and agreeing an antidepressant switching strategy

Monitoring schedules

Generally, people should be reviewed within 2 weeks after starting the new antidepressant for the treatment of depression. People with suicide risk or aged 18 to 25 should be reviewed 1 week after starting the new antidepressant, and then again as often as needed (but no later than 4 weeks after initiation).

Advising people

Ensure the person knows the monitoring they can expect after the switch, by whom, and when. Advise people at their review appointment on aspects such as the:

Time required for treatment effect

It may take 1 to 2 weeks before the benefits of the treatment are felt. If no benefit is seen after 4 to 6 weeks the medicine will need to be reviewed.

Possibility of side-effects

There may be side effects associated with the new antidepressant. It may take several weeks before the benefits of treatment outweigh any problems from side effects.

Risk of withdrawal symptoms

People may experience withdrawal symptoms from stopping their antidepressant treatment. Gradual withdrawal may minimise risk and the person’s symptoms should guide the speed of the switch.

Psychological symptoms

A person may experience symptoms such as:

• irritability
• anxiety
• low mood
• sleep disturbances
• suicidal ideation
• hallucinations

Physical symptoms

A person may experience symptoms such as:

• dizziness
• headaches
• brain “zaps”
• unsteady on feet
• palpitations
• muscle pain
• tremors
• gastrointestinal disturbances (nausea and diarrhoea).

Risk of serotonin syndrome

Serotonin syndrome is an uncommon but potentially serious side effect of most antidepressants. Concomitant or sequential use of antidepressants can increase the risk of serotonin syndrome as most antidepressants increase serotonin levels in the brain.

Symptoms

Can be mild to life-threatening and include:

• autonomic dysfunction (tachycardia, blood pressure changes, hyperthermia, sweating, shivering and diarrhoea)
• neuromuscular hyperactivity (tremor, rigidity, myoclonus, clonus and hyperreflexia)
• altered mental state (agitation, confusion, mania and coma)

Risk of relapse

Medication may be needed for 6 months or longer (if relapse risk is higher) even after remission of symptoms.

Non-addictive nature of antidepressants

Antidepressants do not share the addictive properties of known dependence-producing medicines.

Missed or extra doses

Inform people on how to manage missed or extra doses and the risks associated with stopping an antidepressant.

Self-help

Signpost to available self-help groups and inform people on how and from whom to seek urgent support from.

Further information

• The NHS Website provides an overview on the use of antidepressants including the potential side effects, withdrawal symptoms, serotonin syndrome and the management of missed or extra doses.
• Health Education England provides a good overview of serotonin syndrome.

Individual switches

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

• MAOI to other antidepressants: switching in adults
• Moclobemide to other antidepressants: switching in adults
• Trazodone to other antidepressants: switching in adults
• Vortioxetine to other antidepressants: switching in adults
• SNRIs to other antidepressants: switching in adults
• Agomelatine to other antidepressants: switching in adults
• Mirtazapine to other antidepressants: switching in adults
• Tricyclics to other antidepressants: switching in adults
• SSRIs to other antidepressants: switching in adults

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