Amitriptyline is a tricyclic antidepressant and pain reliever. It was discovered in 1960 and is also marketed under the name Tryptizol or Deprelio. It is on the World Health Organization (WHO) list of medicines essential for their efficacy and safety.
Unlike other tricyclic antidepressants, amitriptyline has an efficacy similar to selective serotonin reuptake inhibitors (SSRIs), so it is one of the most widely used antidepressants in its group.
Amitriptyline is approved and indicated for the treatment and prevention of several different disorders:
It is also sometimes used to treat certain eating disorders and finally, in some cases, helps fight persistent hiccups.
As with most psychotropic medications, it is recommended to start treatment in low doses.
Over time, the dose may be gradually increased depending on the tolerance of the patient’s clinical response. The completion of the use of the medicinal product should be done in the same way: gradually decreasing the dose.
It is usually administered orally, in four daily intakes, it is recommended that they are always at the same time, in addition to always following the instructions that the specialist deems appropriate for each case.
As a tricyclic antidepressant, its mechanism of action is inhibiting the reuptake of norepinephrine and serotonin in nerve endings, which increases the action of these neurotransmitters in the brain and improves depressive states.
Amitriptyline also blocks the ion channels of sodium, potassium and NMDA (N-methyl-D-aspartate), which explains its effect on neuropathic pain and prevention of chronic tension headaches and migraine.
It has a strong affinity for alpha adrenergic, muscarinic M1 and histamine H1 receptors. It is more sedative and has more anticholinergic properties than other tricyclic antidepressants.
Its anti-depressive and analgesic therapeutic action takes between two and four weeks to establish, however its sedative action is quite fast and intense, and side effects may begin to occur at the first dose.
Amitriptyline is very well absorbed by the digestive tract; after administration, nortriptyline is metabolized; it is an active metabolite that also has anti-depressive action; it is a more potent norepinephrine reuptake inhibitor than Serotonin reuptake.
Amitriptyline can cause side effects similar to those of other tricyclic antidepressants, however, anticholinergic symptoms are the most noticeable. Side effects include:
High doses, cardiac arrhythmias and severe hypotension are likely to occur; however, they can also occur at normal doses in patients with heart disease.
Therefore, the use of amitriptyline is contraindicated in patients with any type of heart problem, some examples are heart block, heart rhythm disorders or coronary heart failure.
The combined use with antidepressants MAOIs in complete contrast (monoamine oxidase inhibitors) can cause serotonin syndrome. However, many other medications also interfere with the metabolism and action of amitriptyline.
As with any medicine, certain precautions should be taken and the specialist’s instructions followed. Tolerance and clinical response vary with each patient and doses should be adjusted accordingly.