Antidepressants

Most antidepressants are believed to work by slowing the removal of certain chemicals from the brain. These chemicals are called neurotransmitters. Neurotransmitters are needed for normal brain function. Antidepressants help people with depression by making these natural chemicals more available to the brain.

How long will I have to take an antidepressant?

Antidepressants are typically taken for at least 6 months. In some cases, however, patients and their doctors may decide that antidepressants are needed for a longer time.

Do antidepressants have side effects?

Like most medicines, antidepressant drugs can cause side effects. Not all people get these side effects. Any side effects you have will depend on the medicine your doctor has chosen for you. Your doctor will talk to you about your medicine.

What are the different kinds of antidepressants?

There are many different kinds of antidepressants, including:

• Selective serotonin reuptake inhibitors (SSRIs)
• Tricyclic antidepressants (tricyclics)

SSRIs

SSRIs are a group of antidepressants that includes drugs such as Citalopram (brand name: Celexa), Fluoxetine (brand name: Prozac), Paroxetine (brand name: Paxil) and Sertraline (brand name: Zoloft). These medicines tend to have fewer side effects than the tricyclics. Some of the side effects that can be caused by SSRIs include dry mouth, nausea, nervousness, insomnia, headache and sexual problems. People taking Fluoxetine might also have a feeling of being unable to sit still. People taking Paroxetine might feel tired. People taking Sertraline might have runny stools and diarrheoa. Please see below for more detailed details on each of these drugs.

Coming off or changing doses on these drugs can be difficult and is now referred to as the SSRI Discontinuation Syndrome and can be very unpleasant with symptoms such as dizziness, light-headedness, vertigo or feeling faint, shock-like sensations, head zaps or paresthesia, anxiety; diarrhoea, fatigue, unsteadiness, headache, insomnia, nausea or vomiting, tremor; and visual disturbances.

The worst discomfort is usually caused by those SSRI’s with the shortest half life i.e. Seroxat and those with the longest half life e.g. Prozac are the easiest to cope with.

A half life measures how quickly the drug is washed out of your system so Seroxat is washed out within hours whereas Prozac takes several days to clear.

• Fluvoxamine 16 hours
• Paroxetine: 21.0 hours
• Sertraline: 26 hours
• Citalopram: 36 hours
• Fluoxetine: 48-72 hours – 7-15 days

The best way to overcome the discontinuation syndrome is to reduce the dose extremely slowly – usually much slower than your doctor might be advising and only reduce the dose again once you’re feeling fine. It is ok to take several months to come off these drugs.

Tricyclics

The tricyclics have been used to treat depression for a long time. They include Amitriptyline (brand name: Elavil), Desipramine (brand name: Norpramin), Imipramine (brand name: Tofranil) and Nortriptyline (brand names: Aventyl, Pamelor). Common side effects caused by these medicines include dry mouth, blurred vision, constipation, difficulty urinating, worsening of glaucoma, impaired thinking and tiredness. These antidepressants can also affect a person’s blood pressure and heart rate.

Will antidepressants affect my other medicines?

Antidepressants can have an effect on many other medicines. If you’re going to take an antidepressant, tell your doctor about all the other medicines you take, including over-the-counter medicines and herbal health products (such as St. John’s wort). Ask your doctor and pharmacist if any of your regular medicines can cause problems when combined with an antidepressant. When taken together, some medicines can cause serious problems.

Taking an MAOI antidepressant at the same time as any other antidepressants or certain over-the-counter medicines for colds and flu can cause a dangerous reaction. Your doctor will tell you what foods and alcoholic beverages you should avoid while you are taking an MAOI. You should not take an MAOI unless you clearly understand what medications and foods to avoid. If you are taking a MAOI and your doctor wants you to start taking one of the other antidepressants, he or she will have you stop taking the MAOI for a while before you start the new medicine. This gives the MAOI time to clear out of your body.