Switching antidepressants may lead to drug interactions, side effects, and serious complications. However, a person can safely switch with the correct strategies and medical supervision.

Depression can affect a person’s mood and mental health but can be treatable with antidepressants prescribed by healthcare and mental health professionals. They may also prescribe them for other conditions, such as pain, anxiety, or insomnia.

People may need to switch antidepressants for various reasons. Healthcare professionals can tailor switching strategies for each person due to individual circumstances, risks, or drug interactions. Research is ongoing on the most effective strategies for switching antidepressant medication.

This article discusses reasons for how and why a person may switch antidepressants, as well as the possible side effects of switching.

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People may need to switch antidepressants for various reasons.

Lack of symptom relief

Some types of antidepressants may not provide relief from depression symptoms in some people. Up to 2 in 3 people with major depression do not experience symptom relief from the first antidepressant they try. They can be ineffective as a person’s body may not respond to them.

However, individuals may not experience immediate symptom relief after starting antidepressants. They usually take 4–8 weeks to begin working fully.

Intolerable side effects

Some antidepressants can cause a person to experience unacceptable or intolerable side effects. They can include:

Built up a tolerance

Antidepressants may also become less effective as a person’s brain builds up a tolerance. They may lose their effect over months or years, reducing a person’s symptom relief.

Change in health needs

People may need to switch or stop antidepressants due to changes in their health needs. This may include conditions or events such as:

  • serious physical illness
  • pregnancy
  • surgery

Learn more about antidepressants.

People should always talk with a healthcare professional before stopping or switching antidepressants. Healthcare professionals should always closely observe anyone changing antidepressants, as serious complications may occur.

A healthcare professional may recommend different strategies for switching antidepressants. These depend on a person’s conditions and interactions between the different types of antidepressants. Some switching strategies include slowly reducing the dose of an antidepressant over time to zero, also called tapering.

After tapering, people may take no antidepressants for a period before starting a different antidepressant. This is called a washout period.

Sometimes, the washout period will depend on the half-life of the antidepressant that the person has discontinued. A half-life is the time it takes for the active substance in an individual’s body to reduce by half.

However, these strategies can take a long time. They also usually include long periods when a person has no antidepressant relief for their symptoms. Therefore, doctors may use different strategies with shorter washout periods or quicker tapering. Some strategies use no washout or taper periods at all.

Healthcare professionals will specify a strategy based on the following:

  • a person’s individual risk factors for withdrawal symptoms
  • a person’s preference and experiences during withdrawal symptoms
  • antidepressants characteristics such as half-life

Switching methods include conservative, moderate, or direct strategies. Healthcare professionals may also suggest a cross-taper switch.

The following chart shows which strategies a healthcare professional may use for specific types of antidepressants.

MethodDefinition
Conservative switch• The first antidepressant tapers then stops.
• This is followed by a drug-free washout period of 3–5 half-lives of the antidepressant.
• The new antidepressant then starts according to dosage recommendations.
Moderate switch• The first antidepressant tapers then stops.
• There is a drug-free washout period of 2–4 days.
• The new antidepressant starts at a low dose.
Direct switch• The first antidepressant stops.
• The second antidepressant starts the following day at a typical dose.
Cross-taper switch• The first antidepressant tapers then stops.
• The second antidepressant begins at a low dose at some point during the tapering of the first, so the person takes both at the same time.
• The dose of the second antidepressant increases to a typical dose after the first one stops.

Switching antidepressants may cause various side effects. A person should inform their healthcare professional about any side effects they experience.

Withdrawal

Antidepressant withdrawal symptoms may start after 5 days of stopping antidepressants. They usually last for 1–2 weeks. However, some people experience severe withdrawal symptoms lasting several months or more. These may include:

  • sweating
  • stomach issues
  • restlessness
  • difficulty sleeping
  • changes in mood, such as feeling:
    • anxious
    • confused
    • irritable
    • a low mood
  • unsteadiness
  • a feeling of electric shocks in the head

Serotonin syndrome

Serotonin syndrome (SS), or serotonin toxicity, is a serious condition where a person’s brain has too much serotonin. Serotonin is a chemical produced by a person’s nerve cells. It sends signals between a person’s nerves. Some types of antidepressants called serotonergic drugs can cause a person to experience SS due to:

  • therapeutic use as medication
  • taking more than the medically recommended dose
  • interactions between serotonergic medications and recreational drugs

People may also develop SS if they add certain medications to their existing serotonergic medication. A person with SS may experience mild to severe symptoms. Mild symptoms can include:

  • confusion or being agitated
  • muscle twitches
  • sweating or shivering
  • diarrhea

Severe SS symptoms can include:

  • seizures
  • having an irregular heartbeat
  • unconsciousness

People with severe SS symptoms should seek immediate medical attention. SS can be fatal.

Tapering can last for several weeks or more, depending on the antidepressant:

  • dose
  • type
  • how long a person has been taking it for

Healthcare professionals vary tapering and washout specifically for each person. During a washout period, a person’s body clears the first antidepressant out of their system. Washout periods may take 2–5 days. However, some types of antidepressants may require a longer washout period.

After the washout period, a person can begin taking the second antidepressant. They often start the second antidepressant on a low dose before slowly increasing it to relieve symptoms. This dose may vary depending on the switching strategy a healthcare professional recommends.

The following are common questions about switching antidepressants.

Can you switch antidepressants without tapering?

Switching antidepressants without tapering has a high risk of drug interactions. Healthcare professionals should always supervise any switching.

Can you just switch from one antidepressant to another?

Any switch from one antidepressant to another may have serious complications. People switching antidepressants should do so under guidance and supervision from medical professionals.

People may need to switch antidepressants due to health conditions, building up a tolerance, or unacceptable side effects. Most strategies use tapering off followed by a washout period to allow one antidepressant to leave a person’s body. They can then safely start a second antidepressant, avoiding complications from drug interactions between the two.

Healthcare professionals may vary strategies by tapering off and washout periods to suit each person’s personal and medical needs. People should only switch antidepressants under supervision and guidance from trained medical professionals.