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Medication side effects

Side effects

Like all medications, medications for mental illness can have side effects you should look out for.

Key points about side effects

  • Many people will never feel any side effects. 
  • Some people will feel so bad it makes it hard to stay on the medication.
  • There are some rare side effects that can be life-threatening.
  • Details of side effects are included on the printed leaflet that comes with your medication. For Australians, these leaflets are also published online at NPS Medicinewise. New Zealanders can access this information at Medsafe.
  • Talk to your psychiatrist or GP if side effects are bothering you.

There are two groups of common side effects:

  • physical side effects (such as high blood pressure, weight gain, high cholesterol levels, sexual problems and tremors)
  • psychological side effects (such as restlessness, anxiety, lack of energy, or sleepiness).

Side effects will often feel worst in the first week, then get better over time.

If you have side effects that bother you

Discuss with your doctor:

  • the changes you've noticed since starting medication, both good and bad
  • what matters to you – some side effects might be listed as ‘minor’ in the product information, but to you they might be a major issue
  • what you can do to reduce side effects, such as changing when you take the medication, doing more exercise, eating healthy meals or drinking more water.

What to tell your doctor about yourself:

  • any other medical conditions you have, such as high blood pressure or diabetes
  • if you are pregnant, breastfeeding or considering becoming pregnant
  • other prescription medications you are taking
  • over the counter drugs you take, such as pain killers, antacids or urinary alkalinisers such as Ural®
  • herbal supplements, complementary or alternative medicines and vitamins you are taking
  • if you smoke
  • your alcohol or other drug use
  • your eating habits or dietary restrictions
  • if you drive a truck or heavy vehicle or use machinery for work.

Combining medications

Psychiatrists are experts in how medications interact with each other. This includes all types of substances, from aspirin to herbal supplements, alcohol and prescription drugs.

Your psychiatrist can review these medication combinations. They can change your medication and dose to reduce side effects or interactions.

Page last reviewed Feb 2017 | C1020V1

This is a general guide only, and does not replace individual medical advice. Please speak to your doctor for advice about your situation. The RANZCP is not liable for any consequences arising from relying on this information. Subject matter experts, people with lived experience of mental illness and carers all contributed to this fact sheet.