How amitriptyline works
Amitriptyline is a drug from the group of so-called tricyclic antidepressants. It has a mood-lifting, anxiolytic and calming effect. Amitriptyline also alleviates the intensity of pain caused by nerve pain (neuropathic pain) and reduces the frequency of chronic tension headaches and migraines.
Amitriptyline exerts these effects by influencing the sensitive balance of messenger substances (neurotransmitters) in the brain. These messenger substances transmit nerve signals between the individual brain cells:
Experts currently assume that the development of depression is partly due to a lack of certain neurotransmitters in the brain (e.g. serotonin and noradrenaline). This is where tricyclic antidepressants (TCAs) such as amitriptyline come in: They prevent the reuptake of the neurotransmitters into the original cell so that they can exert their effect for longer.
As a TCA, amitriptyline inhibits the reuptake of various neurotransmitters only slightly selectively. It blocks the reuptake of serotonin and noradrenaline and also binds to numerous other receptors of various signaling pathways in the brain.
This spectrum of activity is different for almost every antidepressant, making it possible to treat numerous mental illnesses with a wide variety of facets.
Absorption, breakdown and excretion
The active substance amitriptyline is only slowly absorbed into the blood (over a period of one to five hours). It is metabolized in the liver, whereby the degradation product also has an antidepressant effect.
After being metabolized, amitriptyline is excreted via the kidneys. It takes around 25 hours for the body to metabolize and excrete half of the active ingredient (half-life).
When is amitriptyline used?
The active substance amitriptyline is approved for the treatment of:
- depressive disorders
- neuropathic pain
- chronic tension headaches and migraines (for prophylaxis)
- Enuresis nocturna (“bedwetting”)
- Attention deficit (hyperactivity) syndrome, in short: ADD or ADHD
- eating disorders
- tinnitus
- Fibromyalgia
It is usually used over a longer period of time.
How amitriptyline is used
The active ingredient amitriptyline is usually used in the form of tablets, sometimes with delayed release. Amitriptyline drops and injection solutions are also available on the German market.
The tablets are usually administered throughout the day (morning – noon – evening). If the amitriptyline dosage is low or the release of the active ingredient is delayed, it is usually taken in the evening, as tiredness can occur, especially at the start of treatment.
What are the side effects of amitriptyline?
Weight gain occurs in more than one in ten people treated with amitriptyline and is therefore a very common side effect of treatment with amitriptyline. In addition, aggression, dizziness, drowsiness, increased heart rate, low blood pressure, nasal congestion, dry mouth, increased sweating, urinary retention and fatigue are very common – especially at the beginning of treatment with amitriptyline.
The effects and side effects occur at different times. Initially, the side effects predominate. These then usually subside after one to two weeks and the actual antidepressant effect comes into play.
What should be considered when taking amitriptyline?
Contraindications
Amitriptyline should not be used in the following cases
- Diseases of the heart
- concomitant treatment with monoamine oxidase inhibitors (MAO inhibitors – for depression and Parkinson’s disease)
- Hypersensitivity to the active substance
Interactions
Amitriptyline can increase the effect of adrenaline, ephedrine and phenylephrine (sympathomimetics) on the heart. It also increases the effect of centrally acting antihypertensives (e.g. clonidine, methyldopa) and anticholinergics (e.g. tolterodine, oxybutynin).
Amitriptyline is broken down in the liver via certain enzymes, so taking inhibitors of these enzymes at the same time can lead to increased amitriptyline side effects. Such inhibitors are, for example, antifungals such as fluconazole and terbinafine, but also other antidepressants such as fluoxetine, paroxetine and bupropion.
Age restriction
Amitriptyline should not be used to treat depressive disorders in children and adolescents under the age of 18 due to a lack of efficacy studies.
However, the active substance is approved for the treatment of enuresis nocturna from the age of six if other measures have not led to the desired success.
Pregnancy and breastfeeding
The active ingredient group of tricyclic antidepressants has been available for more than 60 years. Accordingly, a great deal of experience is available on the effects and side effects – also during pregnancy and breastfeeding.
There is less extensive data on the use of amitriptyline during breastfeeding. So far, no symptoms have been described in breastfed children. Amitriptyline is therefore one of the antidepressants of choice during breastfeeding, provided that drug therapy is indicated.
How to obtain medication with amitriptyline
In Germany, Austria and Switzerland, preparations containing the active ingredient amitriptyline in any dosage and dosage form are only available on prescription and can only be obtained from pharmacies.
Amitriptyline-containing drops are only available in Germany, but not in Austria or Switzerland.
Since when has amitriptyline been known?
Imipramine was the first tricyclic antidepressant to be discovered and first tested in 1955. Amitriptyline was introduced in the USA in 1961 as the second member of the tricyclic antidepressants. Since then, it has been one of the most frequently prescribed antidepressants worldwide and is also used successfully in many other areas of application.
