Home > MEDICATION & YOU > Drug Facts > Antidepressants



Antidepressants are medicines that relieve the symptoms of depression. Antidepressants have anti-anxiety effects too. There are four main types of antidepressants, namely:

  • Tricyclics
  • RIMAs (Reversible Inhibitors of Monoamine Oxidase type A)
  • SSRIs (Selective Serotonin Reuptake Inhibitors)
  • SNRIs (Serotonin and Noradrenaline Reuptake Inhibitors)

How do they work

It is likely that they increase the activity of certain chemicals in our brains called neurotransmitters. They pass signals from one brain cell to another. The chemicals most involved in depression are thought to be Serotonin and Noradrenaline.

How to use

  • Take your medicines daily as directed. Do not try to adjust the medication on your own.
  • Their effects can only be seen after 2 weeks or more, so waiting is essential.
  • Side-effects of the drugs will wear off with time.
  • Consult your doctor if the side effects are too unpleasant. Your doctor may decide to give an alternative medicine.

Adverse Effects


The common side effects of tricyclics include dry mouth, a slight tremor, fast heartbeat, constipation, sleepiness and weight gain. In older people, they probably cause confusion, difficulty in urinating, fainting and fall. If you have a heart problem, it is better to avoid tricyclics. Men may experience problem with erection or delayed ejaculation.


RIMAs can give you a dangerously high blood pressure if you eat food containing a substance called Tyramine. If you agree to take a RIMA antidepressant, your doctor or pharmacist will give you a list of foods to avoid.


Side-effects on the stomach are fairly common and dose-related. They include nausea, vomiting, dyspepsia, abdominal pain, diarrhoea, constipation, anorexia and weight loss. There are other side-effects related to this group.

If you think they are related to the SSRI that you are taking, confirm with your doctor or pharmacist.


Their side effects are similar to the SSRIs.


Some antidepressants make you sleepy and slow down your reaction. Ask your doctor for advice if you are working with heavy machinery or your work involve driving.

Antidepressant drugs are not generally addictive but some people may have withdrawal symptoms when they stop SSRIs or SNRIs. These include stomach upsets, flu like symptoms, anxiety, dizziness, vivid dreams at night and sensations in the body that feel like electric shocks. To minimize these effects your doctor will taper off the dose for you. Do not stop your medication abruptly.

SSRIs can be used with caution for those below 18 years of age if prescribed by doctors.

Any form of antidepressants are best avoided during pregnancy, especially in the first 3 months. There is a risk of congenital abnormalities in babies. Alternative treatment in pregnancy is always considered unless unavoidable in severe depression, that may affect the mother and child’s lives.

  • Driving or operating machinery
  • Withdrawal symptoms
  • Young people
  • Pregnancy

Storage Conditions

Keep your medicines in its original container, tightly closed. Store at room temperature and keep away from children, excess heat or moisture.


Last reviewed : 20 April 2012
Writer : Dr. Nour Hanah bt. Othman
Reviewer : Siti Nurul Fathihah bt. Baharudin