Amitriptyline

Definition

Amitriptyline is a medication used to treat various forms of depression, pain associated with the nerves (neuropathic pain), and to prevent migraine headaches. It is sold in the United States under the brand name Elavil.

Purpose

Amitriptyline helps relieve depression and pain. It is often used to manage nerve pain resulting from cancer treatment. Such injury to nerves causes a burning, tingling sensation. This medication, usually given at bedtime, helps patients sleep better.

Description

This medication is one of several tricyclic antidepressants. Amitriptyline acts to block reabsorption of chemicals that transmit nerve messages in the brain.

Recommended dosage

Amitriptyline's usual adult dose for pain management is 10 mg to 150 mg at bedtime. Patients are generally started on a low dose. The amount of medication may be increased as needed. Side effects, such as a dry mouth and drowsiness, may make it difficult to increase the dose in older adults. Bedtime dosing helps the patient sleep. Doctors generally order 75 mg to 150 mg for depression. It is given at bedtime or in divided doses. It may take 30 days for the patient to feel less depressed. Pain relief is usually noticed sooner than the mood change. Teens and older adults usually receive a lower dose. If the nightly dose is missed, it should not be taken the next morning. Taking amitriptyline during waking hours could result in noticeable side effects. Patients should check with their doctor if the daily dose is missed. Those on more than one dose per day should take a missed dose as soon as it is noted. Patients should not take two doses at the same time. Injectable amitriptyline is available. It should not be used long-term. Patients should switch to tablets as soon as possible.

Precautions

Patients should not suddenly stop taking this medication. The dose should gradually be decreased, then discontinued. If the drug is abruptly stopped, the patient may experience headache, nausea, discomfort throughout the body, and a worsening of original symptoms. Amitriptyline's effects last for three to seven days after the medication has been stopped. Older adults usually are more prone to some side effects. These include drowsiness, dizziness, mental confusion, blurry vision, dry mouth, difficulty urinating, and constipation. Taking a lower dose may help resolve these problems. Patients may need to stop this medication before surgery.

Amitriptyline should not be given to anyone with allergies to the drug or to patients recovering from a heart attack. Patients taking MAO inhibitors, a different type of antidepressant, should not also use amitriptyline. It should be administered with caution to patients with glaucoma, seizures, urinary retention, an overactive thyroid, poor liver or kidney function, alcoholism, asthma, digestive disorders, an enlarged prostate, seizures, or heart disease. This medication should not be given to children under 12. Pregnant women should discuss the risks and benefits of this medication with their doctor. Fetal deformities have been associated with taking this drug during pregnancy. Women should not breastfeed while using amitriptyline.

Side effects

Common side effects associated with amitriptyline include dry mouth, drowsiness, constipation, and dizziness or lightheadedness when standing. Patients can suck on ice cubes or sugarless hard candy to combat the dry mouth. Increased fiber in the diet and additional fluids may help the constipation. The dizziness is usually caused by a drop in blood pressure when changing position. Patients should slowly rise from a sitting or lying position if dizziness is noticed. Amitriptyline may increase the risk of falls in older adults. Patients should not drive or operate machinery or appliances while under the influence of this drug. Alcohol and other central nervous system depressants can increase drowsiness. Amitriptyline may also produce blurry vision and an irregular or fast heartbeat. Amitriptyline also may raise or lower blood pressure, or cause palpitations. This medication may increase or decrease diabetic patients' blood sugar levels. Amitriptyline may make patients' skin more sensitive to the sun. Patients should avoid direct sunlight, wear protective clothing, and apply sunscreen with a protective factor of 15 or higher.

Amitriptyline may increase appetite, cause weight gain, or produce an unpleasant taste in the mouth. It may also cause diarrhea, vomiting, or heartburn. Taking this medication with food may decrease digestive side effects. Other less likely side effects include muscle tremors, nervousness, impaired sexual function, sweating, rash, itching, hair loss, ringing in the ears, or changes in the make up of the patient's blood. Patients with schizophrenia may develop an increase in psychiatric symptoms.

Interactions

Patients should always tell all doctors and dentists that they are taking this medication. Amitriptyline may decrease the effectiveness of some drugs used to treat high blood pressure. Amitriptyline should not be taken with other antidepressants, epinephrine and other adrenaline-type drugs, or methylphenidate. Patients should not take over-the-counter medications without checking with their doctor. For instance, amitriptyline should not be taken with Tagamet (cimetidine) or Neo-Synephrine. Patients taking this drug should avoid the dietary supplements St. John's wort, belladonna, hen-bane and scopolia. Black tea may decrease the absorption of this drug. Patients should ingest the drug and tea at least two hours apart.

Debra Wood, R.N.

MAO inhibitor

—a type of antidepressant medication