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Cautions - Antidepressants

There are several important things to consider when taking antidepressants. You should discuss these with your GP or mental health professional.

Interactions with other medications

Antidepressants can react with other medications, including over-the-counter medications such as Ibuprofen. Always read the patient information leaflet that comes with your medication. This will tell you if there are any medications you should avoid.

If in doubt, talk to your pharmacist or GP.


Antidepressants aren't usually recommended for pregnant women. Especially during the early stages.

Exceptions can be made if the risks posed by a mental health condition outweigh any potential risks of treatment.

For example:

  • a high level of ongoing suicide risk
  • complex resistant depression that may reoccur if you stop taking medication

Potential complications linked to antidepressant-use during pregnancy include:

  • loss of the pregnancy
  • birth defects affecting the baby’s heart (congenital heart disease)
  • pulmonary hypertension - when high blood pressure in the lungs causes breathing difficulties

But there's no hard evidence that antidepressants cause these complications.

If you're pregnant and depressed, discuss the pros and cons with the doctor in charge of your care.


Using antidepressants while you're breastfeeding is not usually recommended.

There are circumstances when the benefits of treatment for a mental health condition might outweigh potential risks. Talk to your doctor.

Children and young people

Antidepressants are not recommended for children and young people under 18. In rare cases, they can trigger thoughts about suicide and acts of self-harm in this age group. They can also affect the development of the brain in children and young people.

An exception will usually only be made if:

  • talking therapies have not worked
  • you will continue to receive talking therapies in combination with antidepressants
  • treatment is supervised by a psychiatrist


You should be wary of drinking alcohol if you're taking antidepressants. Alcohol is a depressant and drinking alcohol can make your symptoms worse.

If you drink alcohol while taking TCAs or MAOIs you may become drowsy and dizzy.

You're less likely to experience negative effects while taking an SSRI or an SNRI. But avoiding alcohol is often still recommended.

Illegal drugs

Do not take illegal drugs if you're taking antidepressants, particularly TCAs. This can cause unpredictable and unpleasant effects.

In particular, you should avoid taking:

  • cannabis – smoking cannabis while taking a TCA can make you feel very ill
  • amphetamines (speed)
  • cocaine
  • heroin
  • ketamine

Illegal drugs can make symptoms of depression or other mental health conditions worse.

Other antidepressants

You should never take two different types of antidepressants. For example, an SSRI and a TCA. Only do this if told to by your doctor. Taking certain combinations of antidepressants can make you feel very ill. It can also be life-threatening.

You may be switched from one type to another. If so, the dosage will be gradually reduced before you start the new type.

St John’s Wort

St John’s Wort is a popular herbal remedy promoted for the treatment of depression.

While there's evidence of its effectiveness, many experts do not recommend it. The amount of active ingredient varies among individual brands and batches. This makes the effects unpredictable.

Taking it with other medications can also cause serious health problems.

For example:

  • anticonvulsants
  • anticoagulants
  • antidepressants
  • the contraceptive pill

Do not take St John's Wort if you're pregnant or breastfeeding. It's unclear whether it's safe.

St John’s Wort may affect your liver’s ability to break down and metabolise certain medications. Talk to your GP or pharmacist if you intend to take it with prescribed medication.

Driving and operating machinery

Some antidepressants can cause:

  • dizziness
  • drowsiness
  • blurred vision

If you do experience these problems, avoid driving or using tools and machinery.

Cautions for specific antidepressants


SSRIs may not be suitable if you have:

  • bipolar disorder and you're in a manic phase
  • a bleeding disorder, or if you're taking medicines that make it more likely you may bleed, such as Warfarin
  • type 1 diabetes and type 2 diabetes
  • epilepsy - only take them if your epilepsy is well controlled and stop if your epilepsy gets worse
  • kidney disease


SNRIs may not be suitable if you have a history of heart disease. Or you have poorly-controlled high blood pressure.


TCAs may not be suitable if you have:

  • a history of heart disease
  • recently had a heart attack
  • liver disease
  • an inherited blood disorder called porphyria
  • bipolar disorder disorder
  • schizophrenia
  • a growth on your adrenal glands that is causing high blood pressure (pheochromocytoma)
  • an enlarged prostate gland
  • narrow-angle glaucoma – increased pressure in the eye
  • epilepsy

Content supplied by the NHS and adapted for Ireland by the HSE

Page last reviewed: 20 August 2022
Next review due: 20 August 2025

This project has received funding from the Government of Ireland’s Sláintecare Integration Fund 2019 under Grant Agreement Number 123.