Amitriptyline belongs to a family of medications known as tricyclic antidepressants. It is used for the treatment of depression. It works in the central nervous system (CNS) to elevate the mood of people with depression.

Your doctor may choose to use this medication for other conditions not listed here. If you're unsure why you are taking this medication, contact your doctor.

The usual maintenance dose of amitriptyline for adults ranges from 50 mg to 100 mg per day in divided doses. For some people, the daily dose can be given as a single dose, preferably at bedtime. People who are very ill or hospitalized may need daily doses of 200 mg to 300 mg. The dose of amitriptyline is usually started at a low level and carefully increased upwards as prescribed by the doctor until the medication is deemed effective.

Many things can affect the dose of medication that a person needs, such as body weight, other medical conditions, and other medications. If your doctor has recommended a dose different from the ones listed here, do not change the way that you are taking the medication without consulting your doctor.

It is very important that this medication be taken on a regular schedule as prescribed by the doctor. If you miss a dose of this medication take it as soon as you remember it. If it is almost time for your next dose, skip the missed dose and carry on with your regular schedule. Do not double doses.

10 mg: Each blue, discoid-shaped, film-coated tablet, engraved "MSD 23" on one side, contains amitriptyline hydrochloride 10 mg. Nonmedicinal ingredients: brilliant blue (sodium and sodium alumina), calcium phosphate dibasic dihydrate, carnauba wax, colloidal silicon dioxide, cornstarch, hydroxypropyl cellulose, hydroxypropyl methylcellulose, lactose, magnesium stearate, powdered cellulose, stearic acid, talc, and titanium dioxide.

25 mg: Each yellow, discoid-shaped, film-coated tablet, engraved "MSD 45" on one side, contains amitriptyline hydrochloride 25 mg. Nonmedicinal ingredients: brilliant blue sodium alumina, calcium phosphate dibasic dihydrate, carnauba wax, colloidal silicon dioxide, cornstarch, hydroxypropyl cellulose, hydroxypropyl methylcellulose, lactose, magnesium stearate, powdered cellulose, quinoline yellow, stearic acid, sunset yellow, talc, and titanium dioxide.

50 mg: Each beige, discoid-shaped, film-coated tablet, engraved "MSD 102" on one side, contains amitriptyline hydrochloride 50 mg. Nonmedicinal ingredients: calcium phosphate dibasic dihydrate, carnauba wax, colloidal silicon dioxide, cornstarch, hydroxypropyl cellulose, hydroxypropyl methylcellulose, lactose, magnesium stearate, powdered cellulose, quinoline yellow, red and black iron oxides, stearic acid, sunset yellow, talc, and titanium dioxide.

75 mg: Each orange, discoid-shaped, film-coated tablet, engraved "MSD 430" on one side, contains amitriptyline hydrochloride 75 mg. Nonmedicinal ingredients: calcium phosphate dibasic dihydrate, carnauba wax, colloidal silicon dioxide, cornstarch, hydroxypropyl cellulose, hydroxypropyl methylcellulose, lactose, magnesium stearate, powdered cellulose, stearic acid, sunset yellow alumina, talc, and titanium dioxide.

Amitriptyline should not be taken:

• during the immediate time following a heart attack
• by anyone with acute congestive heart failure
• by anyone who is taking an MAO inhibitor (e.g., phenelzine, tranylcypromine) or has taken one in the past 14 days
• by anyone with an allergy to amitriptyline or to any of the ingredients of the tablets

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your health professional. They may be able to help you to deal with some of the effects.

The following side effects may go away as your body becomes used to the medicine; check with your doctor if they continue or become bothersome.

More common

• dizziness
• drowsiness
• dryness of mouth
• headache
• increased or decreased appetite (increased appetite may include craving for sweets)
• nausea
• tiredness or weakness (mild)
• unpleasant taste
• weight gain or loss

Less common or rare

• diarrhea
• heartburn
• increased sweating
• trouble sleeping
• vomiting
• nightmares

Check with your doctor as soon as possible if any of the following side effects occur:

Less common

• blurred vision
• confusion or delirium
• constipation (especially in the elderly)
• decreased sexual ability
• difficulty in speaking or swallowing
• eye pain
• fainting
• fast or irregular heartbeat (pounding, racing, skipping)
• hallucinations
• loss of balance control
• mask-like face
• nervousness or restlessness
• problems in urinating
• shakiness or trembling
• shuffling walk
• slowed movements
• stiffness of arms and legs

Rare

• anxiety
• breast enlargement in both males and females
• hair loss
• inappropriate secretion of milk (females)
• increased sensitivity to sunlight
• irritability
• muscle twitching
• numbness or tingling of the fingers or toes
• red or brownish spots on skin
• ringing, buzzing, or other unexplained sounds in the ears
• seizures
• slurred speech
• skin rash, itching, or hives
• sore throat and fever
• swelling of face and tongue
• swelling of testicles
• trouble with teeth or gums
• weakness
• yellow eyes or skin

Some people may experience side effects other than those listed. Check with your doctor if you notice any symptom that worries you while you are taking this medication.

Medical conditions: Amitriptyline should be used with caution by people with a history of:

• seizures
• reduced liver function
• certain blood disorders
• urinary retention
• narrow-angle glaucoma
• increased eye pressure

Heart diseases: Tricyclic antidepressant drugs such as amitriptyline, particularly when taken in high doses, can cause abnormal heart rhythms. They should be taken with caution by people who have a history of heart disease or are elderly.

Thyroid disease: Patients who have an overactive thyroid (hyperthyroidism) or are taking thyroid medication should be monitored closely when taking amitriptyline.

Withdrawal: Stopping this drug abruptly after taking it for a long time may produce nausea, headache, and malaise. Gradual dosage reduction has been reported to produce, within two weeks, transient symptoms including irritability, restlessness, and dream and sleep disturbance. Experiencing these symptoms does not mean you are addicted.

Occupational hazards: Amitriptyline may reduce mental and/or physical abilities required for performance of hazardous tasks such as operating machinery or driving a motor vehicle. Do not undertake such activities until you have determined that it does not have this effect on you.

Pregnancy: This medication has not been adequately studied with pregnant women. The potential benefits must be weighed against the possible hazards to mother and child.

Breast-feeding: Amitriptyline is excreted in breast milk. Because of the potential for serious side effects in infants, a decision should be made whether to stop nursing or stop the drug.

Children: Because of the lack of experience with the use of this drug in the treatment of depression in children, amitriptyline is not recommended for depressed patients under 12 years of age.

• anticholinergic drugs (e.g., atropine)
• antifungals (e.g., fluconazole, ketoconazole)
• barbiturates (e.g., phenobarbital)
• buproprion
• cimetidine
• divalproex sodium
• disulfiram
• ethchlorvynol
• fenfluramine
• fluoxetine
• fluvoxamine
• furazolidone
• MAO inhibitors (e.g., phenelzine, tranylcypromine)
• propafenone
• rifampin
• rifabutin
• sparfloxacin
• sertraline
• stimulant drugs (e.g., appetite suppressants, epinephrine, norepinephrine)
• valproic acid

The following medications may be affected by amitriptyline:

• alcohol
• antihistamines
• carbamazepine
• cisapride
• clonidine
• dicumarol
• guanethidine
• levodopa
• lithium
• other medications that can cause sedation (e.g., barbiturates, sedatives, sleeping pills, anaesthetics)
• opioids (e.g., morphine)
• warfarin

If you are taking any of these medications, speak with your doctor or pharmacist. Depending on your specific circumstances, your doctor may want you to:

• stop taking one of the medications,
• change one of the medications to another,
• change how you are taking one or both of the medications, or
• leave everything as is.

An interaction between two medications does not always mean that you must stop taking one of them. In many cases, interactions are intended or are managed by close monitoring. Speak to your doctor about how any drug interactions are being managed or should be managed.

Medications other than those listed above may interact with this medication. Tell your doctor or prescriber about all prescription, over-the-counter (non-prescription), and herbal medications that you are taking. Also tell them about any supplements you take. Since caffeine, alcohol, the nicotine from cigarettes, or street drugs can affect the action of many medications, you should let your prescriber know if you use them.