Amitriptyline (Elavil, Endep, Tryptanol, Elatrol, Tryptizol, Trepiline, Laroxy)

Amitriptyline is a tricyclic antidepressant that has been in use since the 1950's.

The Bottom Line: What You Really Need to Know

Uses

Amitriptyline is primarily used to treat depression. It's also used to treat bedwetting, insomnia, headaches, chronic pain, fibromyalgia, interstitial cystitis, irritable bowel syndrome, multiple sclerosis, carpal tunnel syndrome, chronic fatigue syndrome, dyspepsia, eating disorders and some skin disorders.

Dosage and instructions

The initial dose of amitriptyline to treat depression is 25 mg three times a day. The dose is increased at intervals of several days to an effective dose of 150-300 mg/day. It can be taken in divided doses or in a single daily dose, preferably in the evening. Amitriptyline may cause drowsiness; taking it in the evening can promote sleep. After a therapeutic effect has been achieved, the dose is gradually lowered to the lowest amount of the medication that will maintain that effect. The usual maintenance dose is 50-100 mg/day.

Adolescents and elderly people will probably need lower doses.

The dose is usually lowered in patients with liver disease.

Smaller doses are used for other effects:

How amitriptyline works

Amitriptyline is a tricyclic antidepressant. The exact way it works is unclear, but it probably works by inhibiting the reuptake of various neurochemicals.

Neurochemicals are important in the way nerves function and communicate with each other. One nerve cell releases certain neurochemicals into the space between cells, and the chemicals bond with specific molecules on the membrane of the next cell. Some of the neurochemicals are also reabsorbed by the cell that released them. In order for cells to function properly, there has to be enough of the neurochemicals available.

Some of these neurochemicals seem to regulate mood and anxiety, especially serotonin, dopamine and norepinephrine. Amitriptyline probably keeps the neurochemicals from being reabsorbed by the releasing cell, allowing them to accumulate in the intercellular space.

Amitriptyline is not very specific in which neurochemicals it blocks and some of the side effects associated with it are due to its effect in blocking other neurochemicals. In addition to blocking serotonin and norepinephrine, amitriptyline also blocks dopamine, H1 histamine and muscarinic (anticholinergic) reuptake.

Side effects

The most common side effects of amitriptyline are weight changes, drowsiness or nervousness, dizziness and insomnia. Other side effects that can occur are:

Interactions

Amitriptyline can have a dangerous interaction with monamine oxidase inhibitor antidepressants that is characterized by high fever, muscle rigidity, convulsions and sometimes death. It should not be taken within two weeks of taking an MAOI.

Amitriptyline increases the effect of alcohol and narcotics on the brain.

It can decrease or increase the action of some medications for asthma, heart disease, high blood pressure, over-the-counter cold medicines and some weight loss medicines.

It blocks the action of guanethidine (Ismelin), a blood pressure medication that is no longer used in the US.

The interaction between amitriptyline and ethchlorvynol (Placidyl or disulfram(Antabuse) can cause delirium.

The dose of amitriptyline may need to be decreased if you are taking cimetadine (Tagamet).

Grapefruit can affect absorption of amitriptyline.

Withdrawal from amitriptyline

At doses that are therapeutic for depression, amitriptyline can cause withdrawal symptoms. The dose should be tapered gradually over several weeks. Withdrawal symptoms can include dizziness, anxiety, agitation and tremors.

Warnings, precautions and contraindications

Increased suicide risk: Antidepressants may increase the risk of suicide, especially in the early weeks of therapy. Anyone who starts taking an antidepressant should be monitored closely, including weekly visits with a physician or therapist. With amitriptyline, this should last for at least 12 weeks. Friends and family should be instructed to check in with the person daily during this time. Any unusual symptoms, such as thoughts of harming self or others, deepening depression, agitation and restlessness, hostility, hallucinations and unusual thoughts should be reported to the physician immediately.

Bipolar disorder and activation of mania: Amitriptyline can activate mania or rapid cycling in people with bipolar disorder. Manic episodes can be very severe and can include psychosis, paranoia, hostility and violent behavior.

Interactions with other antidepressants: Most antidepressants have an effect on neurotransmitters, especially serotonin. If they are used together a severe reaction called serotonin syndrome can result. This is a toxic syndrome and can lead to death.

Amitriptyline should be used with caution in people who have:

It should also be used with caution in children younger than 12 years of age. The medication should not be taken for several days before surgery.

Amitriptyline is contraindicated in people who have recently had a heart attack or who have congestive heart failure.

blog comments powered by Disqus