How Antidepressant Medication Works

Normally the brain would release sufficient quantities of neurotransmitters to stimulate other cells but as quickly as they are released they are re-absorbed into the brain cells. In depression fewer neurotransmitters are released, the action of tricyclics is to block the re-uptake of the neurotransmitters serotonin and noradrenaline, increasing the level outside the brain cells this then prolongs the effect these neurotransmitters have on the brain cells.

Tricyclic Antidepressants

Tricyclic’s the likes of amitriptyline are mainly sedative and are said to improve sleeping habits even before the depression is relieved. Tricyclic’s block the re-uptake of neurotransmitters, (serotonin and noradrenaline) thus increasing neurotransmitter levels. On the other hand tricyclic’s such as lofepramine or imipramine are said not to be sedative and are given to people who feel lethargic. Side-effects such as blurred vision, dry mouth, and urinating problems among others, come with most of the tricyclic’s. It is not a matter of course that you will suffer adverse effects taking a tablet from this particular family of drugs. There are people who have reported having few concerns with side effects and also those who have not suffered any ill effects.

Selective Serotonin Re-uptake inhibitors

The action of these particular drugs block the re-uptake of the neurotransmitter known as Seratonin, increasing its effect on the nerve endings by raising its levels. SSRI’s are said to have fewer side effects than TCA’s but may still cause nausea and or vomiting. It is known that SSRI’s may also cause anxiety, headache and restlessness at the start of treatment.

Monoamine Oxidase Inhibitors

Where the tricyclic’s block the re-uptake of excitatory neurotransmitters (serotonin and noradrenaline), monoamine oxidase inhibitors block the action of the enzyme that would normally break them down this allows the neurotransmitters to build up thus allowing a greater stimulation. Usually given to people who do not respond to tricyclic’s or if for what ever reason tricyclics are not suitable. MAOI’s are at their best if used to treat people who are anxious as well as being depressed, also good for those who suffer from phobias.

When taken with certain drugs, or foods rich in tyramine (e.g. yeast extract, cheese, meat and red wine), monoamine oxidase inhibitors can produce a large rise in blood pressure often accompanied with a headache and vomiting. If you are taking MAOI’s you should be given a card that lists both drugs and foods considered dangerous while on this medication. It also helps others to be aware of your requirements should you ever be in an accident, or in a position where you are unable to pass your use of these drugs on.

Having said all that, because of the interaction with other drugs and foods treatment with monoamine oxidase inhibitors (MAOI’s) these days are often bypassed, in preference for selective serotonin re-uptake inhibitors (SSRI’s).

Moclobemide is a newer MAOI that has been developed which is much less likely to cause unwanted symptoms when taken with food.

Dependency may evolve if you were on these type of medications over a large time scale. Almost all doctors these days are aware of this and would not prescribe the drug if the individual could cope without it.

Health Effects

The effects of antidepressant drugs start after 10 to 14 days of treatment and it could be as long as six to eight weeks before the full beneficial effects of these type of drugs will be felt. However the side-effects these drugs carry with them may be felt from day one. Treatment should still be continued as it is documented that the body will become tolerant to these side-effects.

Most of the tricyclic’s have one particular side effect, drowsiness, while this in its self can cause problems for the person taking the drug in the initial stages if the last dose of the day is taken near going to bed for the night it does help to bring much needed sleep, if one of the problems experienced in the depression is not being able to sleep at night. This then rules out the need for a separate drug such as Temazepam a Benzodiazepine sleeping drug to be administered.

Health Risks

An overdose of tricyclic’s or MAOI’s is extremely dangerous; tricyclic’s can result in coma, fits and even upset the rhythm of the heart, which in turn could lead to death. If you suffer from epilepsy or have a heart problem these drugs would be prescribed with caution and have a number of side effects. These particular kinds of medication deactivate enzymes that would normally break down certain chemicals found in some foods.

Most side effects are reported to be minor and should disappear within a few short weeks.

Below are listed a number of the most common medications used to treat depression. Highlighted medications will open in a new window.

Tricyclics antidepressants (TCA’s) Selective serotonin re-uptake inhibitors (SSRI’s)
Amitriptyline. Citalopram.
Amoxapine Escitalopram.
Clomipramine. Fluoxetine.
Dosulepin. Fluvoxamine
Doxepin Paroxetine
Imipramine. Sertraline.
Lofepramine.
Nortriptyline
Trimipramine.
Monoamine Oxidase Inhibitors (MAOI’s) Other Medication
Moclobemide. flupentixol
Phenelzine. Maprotiline
Isocarboxazid Mianserin.
Tranylcypromine Mirtazepine.
—- Nefazodone
Reboxetine
Trazodone.
Tryptophan
Venlafaxine.
Highlighted medication will open is a new window