Key points
- Amitriptyline is a tricyclic antidepressant, listed for major depressive disorder and neuropathic pain.
- Tablets come in 10 mg, 25 mg, 50 mg and 75 mg strengths.
- A dose acts for around 24 hours, while the full effect usually builds over 2 to 4 weeks.
What amitriptyline is used for
Amitriptyline is used for major depressive disorder, where low mood can come with disturbed sleep and low energy. It is also used for neuropathic pain, the burning, shooting or electric-shock sensations that arise when nerves are damaged or irritated. One example is post-herpetic neuralgia, the burning or stabbing pain that can last for months or years after a shingles infection.
A third use is migraine prophylaxis. There the tablet is taken on a regular schedule to reduce how often attacks happen, rather than to settle an attack that has already begun. The dose and the length of treatment differ between these uses.
How amitriptyline works
Amitriptyline inhibits the neuronal reuptake of serotonin and noradrenaline. Nerve cells normally take these two messengers back once a signal has travelled along them; blocking that reuptake leaves more serotonin and noradrenaline present in the central nervous system. Mood pathways and pain pathways both respond to this change in signalling, which is how one medicine can be useful in depression and in nerve pain.
The shift is gradual, so the tablet is taken on a regular schedule rather than as a one-off.
Amitriptyline tablets and strengths
Amitriptyline is supplied as a tablet in 10 mg, 25 mg, 50 mg and 75 mg strengths, with amitriptyline as the active ingredient. Having four strengths gives some room to adjust the amount taken without moving to a different medicine, and tablets are the only form.
Orders sent to Malaysia are packed discreetly by pharmacy partners in India.
Safety
A recent myocardial infarction and heart block are both contraindications, so any heart history matters before treatment starts. Amitriptyline may impair the ability to drive, and it is worth knowing how it affects you before driving or working with machinery.
Dry mouth and drowsiness are the minor effects usually mentioned. Blurred vision, constipation and urinary retention are moderate effects. A cardiac arrhythmia is a serious effect and requires immediate medical attention.
Alcohol and MAOIs are the interactions to avoid. Older patients are treated with caution. The medicine is not recommended in pregnancy, and during breastfeeding it should be used with caution because it is excreted in milk.
What the sources say
- A boxed warning says antidepressants raised the risk of suicidal thinking and behaviour compared with placebo in children, adolescents and young adults in short-term studies of major depressive disorder and other psychiatric disorders. (DailyMed)
- The same warning reports no increase in that risk in short-term studies of adults over 24, and a reduction in risk in adults aged 65 and older. It asks for close observation of patients of all ages who start treatment, looking for clinical worsening, suicidality or unusual changes in behaviour, and states that the tablets are not approved for use in paediatric patients. (DailyMed)
- A syndrome resembling neuroleptic malignant syndrome has been reported very rarely after amitriptyline is started or its dose is increased. (DailyMed)
- The label notes that the enzyme cytochrome P450 2D6 is less active in a subset of the population, and that these people can reach higher than expected plasma concentrations of tricyclics such as amitriptyline at usual doses. (DailyMed)
Further reading