All types of antidepressants can cause some side effects. The most common problems are sleepiness, dry mouth, constipation, nausea and sexual problems. Some people react badly to antidepressants; in others side effects can be quite mild.

Different drugs have different risks: SSRIs, or selective serotonin reuptake inhibitors, such as fluoxetine (Prozac) may cause you to feel sick or more anxious during the first couple of weeks. Some types of SSRI can cause indigestion, but this can usually be avoided by taking them with food. They may interfere with sexual function, and there have been reports of episodes of aggression, although these are rare. Side effects of SSRIs tend to become less obvious after the first few weeks, while the body adapts to the drug. The exception is sexual side effects, which tend to occur later on.

SNRIs, or serotonin-norepinephrine reuptake inhibitors, such as venlafaxine (Effexor) share many of the same side effects as SSRIs, because both elevate serotonin levels. The most common problems are loss of appetite, weight gain, and difficulty sleeping. You may also experience drowsiness, dizziness, fatigue, headache, nausea and vomiting and sexual dysfunction. As the drugs also raise norepinephrine levels, they can sometimes cause anxiety, mildly elevated pulse, and increased blood pressure.

Tricyclic antidepressants such as imipramine (Tofranil) can trigger drowsiness, a dry mouth, fast heartbeat, constipation and dizziness. The drowsiness may become less noticeable after taking the drug for a while, but the other side effects probably won’t. Older people in particular may experience confusion, difficulty urinating, low blood pressure and falls. These drugs can have cardiovascular effects, so if you have heart trouble it may be best not to take one of this group of antidepressants.

Rare side effects of MAOIs (monoamine oxidase inhibitors) such as phenelzine (Nardil) and tranylcypromine (Parnate) include liver inflammation, heart attack, stroke, and seizures. Patients may have to be careful about eating certain smoked, fermented, or pickled foods, drinking certain beverages, as they can cause severe problems in combination with the medication. A range of other, less serious side effects occur including weight gain, constipation, dry mouth, dizziness, headache, drowsiness, insomnia, and sexual problems. Due to the interactions with diet and over-the-counter and prescription medicines, this type of antidepressant is now rarely prescribed.

Handling Symptoms

  • Be warned in advance. Make sure you get advice from your doctor or psychiatrist on what to expect. You should remind him or her of any medical conditions you have or have had in the past. Read the patient information leaflet that comes with your medicine.

    Monitor any side effects you experience. Keep track of physical and emotional changes and mention them to your doctor. Some of these side effects settle down with time, but contact your doctor if your depression gets worse, and immediately if you experience suicidal thoughts.

    If the side effects are interfering with your daily life, or making you very uncomfortable, consider talking to your doctor about changing to a different medication; decreasing the dose; taking the drug in several smaller doses spread through the day; or taking extra medication to counteract the side effects.

Specific Coping Strategies

  • Increase in appetite – Limit your fat intake and fill up on fruit, yogurt, and sensible snacks such as oat cakes. Be careful with high-sugar fizzy drinks.

    Constipation – Increase exercise, try dried apricots, and increase your water intake.

    Dizziness – Get up slowly from lying or sitting down, avoid excessively hot showers or baths, avoid alcohol, sedatives or other sedating drugs (e.g. marijuana).

    Drowsiness – Take medication in a single dose before bedtime (talk to the doctor about this first). If you feel sleepy during the day, you shouldn’t drive or work with machinery.

    Dry mouth – Ensure regular fluid intake, limit alcohol and caffeine which can be diuretic, try sugarless chewing gum and sweets.

    Sensitivity to sunburn – Avoid the midday sun, use sunscreen regularly and wear a hat, sunglasses and long-sleeved top.

Antidepressant withdrawal

You may get withdrawal symptoms when you stop taking antidepressants. Symptoms of sudden withdrawal include feeling sick, vomiting, loss of appetite, headaches, dizziness, chills, insomnia, anxiety and panic. If you want to stop taking antidepressants, talk to your doctor first. He or she may suggest that you reduce the dose slowly, as this can prevent withdrawal symptoms. If withdrawal symptoms do occur, they will usually last less than two weeks. An option if they do occur is to restart the drug and reduce the dose even more slowly.



The Royal College of Psychiatrists