Amitriptyline is a generic tricyclic antidepressant that is used in the treatment of depression. It is sold under the brand names Elavil, Endep, Enovil and Emitrip. Amitriptyline is also used to treat chronic pain and fibromyalgia.
Trycyclic antidepressants work by increasing the concentrations of two monoamine neurotransmitters called norepinephrine and serotonin. It is believed that reduced levels of these transmitters are associated with depression. The neurotransmitters are secreted and then reabsorbed by the same cells. Trycyclics work by inhibiting the reabsorbtion (reuptake) of these transmitters so that they stay active for longer.
Amitriptyline is used primarily to treat endogenous depression - that is depression that is not in response to external depressing events (reactive depression). In multiple sclerosis, it is believed that some lesions can directly cause endogenous depression. However, given the rather depressing nature of the disease itself, it is often difficult to separate the reactive and endogenous forms of depression.
Amitriptyline is more likely to be effective on endogenous depression than other forms. Because it also has a sedative effect, it is also effective in treating the anxiety associated with such depression.
When used with bipolar depression (formally called manic depression), amitriptyline can cause manic episodes.
In common with other tricyclic antidepressants, amitriptyline should NOT be used in combination with another variety of antidepressants called MAO inhibitors (eg. phenelzines (Nardil, Nardelzine) and tranylcypromine (Parnate, Sicoton)). If tricyclic antidepressants are to be substituted for MAO inhibitors, then there should be a separtion period of at least 14 days during which neither antidepressant is taken.
Amitriptyline should also not be used by people who have already demonstrated an adverse reaction to tricyclic antidepressants. It is also counter-indicated for people with a history of seizures, liver problems, urinary retention (relatively common in multiple sclerosis), digestive conditions, glaucoma or increased intraocular pressure. Use by people with cardiovascular problems, diabetics and pregnant or nursing mothers should be closely monitored by a doctor.
You should avoid driving or operating heavy machinery as amitriptyline can make you dizzy. It can also make you more sensitive to sunlight and you should use a sunscreen when outdoors.
The following side-effects of Amitriptyline are deemed to be mild and do not require urgent medical intervention although you should mention them to your doctor: decreased sexual ability, muscle twitching, sensitivity to sunlight, shakiness, weakness, incontinence or urinary hestitancy, blurred vision, weight gain, constipation or diarrhea, dizziness, mild headaches and fatigue. Many of these are common symptoms of multiple sclerosis.
More serious side-effects include: fast or irregular heartbeat, fainting, confusion, agitation, hallucinations, increased sweating, fever, neck stiffness, chest pain, breathing difficulties, severe headaches, convulsions, vomiting or nausea, dark urine, jaundice, skin rash, liver spots or hives. You should consult a doctor immediately if you get any of these side-effects.
Amitriptyline is potentially lethal in overdose. Do not exceed the stated dose.
ICN Drug Glossary: Oral Medications - Tricyclic Antidepressants
HealthyWay - Perphenazine and Amitriptyline - oral
Yahoo! Health - Medication or Drug - oral Amitriptyline