Products
Amitriptyline is commercially available as film-coated tablets and capsules (Saroten, limbitrol + chlordiazepoxide). It has been approved in many countries since 1961. The distribution of tryptizole was discontinued in 2012.
Structure and properties
Amitriptyline (C20H23N, Mr = 277.4 g/mol) is present in drugs as amitriptyline hydrochloride, a white powder or colorless crystals that are readily soluble in water. The active ingredient is derived from imipramine and belongs to the tricyclic antidepressants. In the liver, amitriptyline is biotransformed to the pharmacologically active nortriptyline by -demethylation via CYP3A4. Amitriptyline is also administered in the form of its prodrug amitriptyline oxide (Equilibrin).
Effects
Amitriptyline (ATC N06AA09) has antidepressant, antianxiety, depressant, and sleep-inducing properties. It is anticholinergic, antihistamine, and analgesic. The effects are due to inhibition of the reuptake of serotonin and norepinephrine into the presynaptic neuron. Amitriptyline additionally binds to several neurotransmitter receptors. Antidepressant effects are delayed within 2-4 weeks.
Indications
For the treatment of depressive disorders and chronic pain. The combination with chlordiazepoxide is used to treat depression when anxiety is a significant symptom. Amitriptyline is used off-label for other indications.
Dosage
According to the SmPC. Treatment is started creeping in and stopped creeping out.
Contraindications
Numerous precautions and drug-drug interactions must be observed during use. Full details can be found in the drug label.
Adverse effects
The most common possible adverse effects include visual disturbances, weight gain, headache, dizziness, tremor, drowsiness, dry mouth, constipation, nausea, palpitations, low blood pressure, and increased sweating. Tricyclic antidepressants are anticholinergic. This explains some of the side effects.
