Amitriptyline (Adverse effects)
Amitriptyline, in addition to being used as an antidepressant (TCA, tricyclic antidepressant), is used to prevent migraine attacks and severe headaches when medications to relieve attacks do not work.
However, there are many people for whom amitriptyline has no effect or causes many side effects, which leads to abandonment of the medication and therefore to therapeutic failure.
Often, amitriptyline produces side effects or does not work because people can present loss of function variants in the genes that metabolize amitriptyline. This therapeutic failure could be avoided if these genetic variants are previously analyzed, and the doses of amitriptyline are properly adjusted.
-Hypersensitivity to amitriptyline.
-Recent myocardial infarction, any degree of heart block or heart rhythm disorders and/or coronary artery insufficiency.
-Amitriptyline is contraindicated together with MAOI treatment.
-Amitriptyline is contraindicated in patients with severe liver disease.
-Amitriptyline potentiates its toxicity in concomitance with MAOIs, do not start treatment until 14 days after finishing treatment with MAOIs.
-Amitriptyline potentiates the effects of alcohol, barbiturates, benzodiazepines, anticholinergics/sympathomimetics (risk of paralytic ileus) and analgesic opioids.
-There is a risk of agranulocytosis if amitriptyline is taken together with antithyroid drugs.
-There is a risk of serotonin syndrome in concomitance with serotonin enhancers.
-Plasma levels of amitriptyline are increased with cimetidine, quinidine, antidepressants, phenothiazines, haloperidol, antiarrhythmics (class 1C), propafenone, flecainide, fluoxetine, sertraline and paroxetine, cytochrome P450 inhibitors (ketoconazole, ritonavir, etc.).
-Plasma levels of amitriptyline are decreased with barbiturates, cytochrome P450 inducers (carbamazepine, phenytoin, hypericum...).
Dry mouth, sedation, blurred vision, constipation, urinary retention, drowsiness, orthostatic hypotension, tachycardia, muscle tremors, nervousness or restlessness, parkinsonian syndrome.
Cardiac arrhythmia, myocardial depression, ECG changes (QT and QRS interval prolongation). Sexual dysfunction, suicidal thoughts and behavior, and bone fractures.
Gene or region studied