How does this medication work? What will it do for me?

Amitriptyline belongs to a family of medications known as tricyclic antidepressants. It is used to treat depression. It works in the central nervous system (CNS) to elevate the mood of people with depression. It is believed to work by keeping the balance of natural chemicals (neurotransmitters) in the body, namely serotonin and norepinephrine. It may start to work within 3 to 4 days, but it may take up to 30 days to see the full effects.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. As well, some forms of this medication may not be used for all of the conditions discussed here. If you have not discussed this with your doctor or are not sure why you are taking this medication, speak to your doctor. Do not stop taking this medication without consulting your doctor.

Do not give this medication to anyone else, even if they have the same symptoms as you do. It can be harmful for people to take this medication if their doctor has not prescribed it.

What form(s) does this medication come in?

10 mg
Each round, blue, biconvex, film-coated tablet, engraved "10" on one side, contains amitriptyline HCl 10 mg. Nonmedicinal ingredients: microcrystalline cellulose, croscarmellose sodium, magnesium stearate, colloidal silicon dioxide, hydroxypropyl methylcellulose, polyethylene glycol, titanium dioxide, carnauba wax, and Brilliant Blue FCF AL Lake 12%.

25 mg
Each round, yellow, biconvex, film-coated tablet, engraved "25" on one side, contains amitriptyline HCl 25 mg. Nonmedicinal ingredients: microcrystalline cellulose, croscarmellose sodium, magnesium stearate, colloidal silicon dioxide, hydroxypropyl methylcellulose, polyethylene glycol, titanium dioxide, carnauba wax, and D&C Yellow No. 10 AL 14%-18%.

50 mg
Each round, brown, biconvex, film-coated tablet, engraved "50" on one side, contains amitriptyline HCl 50 mg. Nonmedicinal ingredients: microcrystalline cellulose, croscarmellose sodium, magnesium stearate, colloidal silicon dioxide, hydroxypropyl methylcellulose, polyethylene glycol, titanium dioxide, carnauba wax, Sunset Yellow AL Lake 40%, and Indigotine AL Lake 12%-14% (Blue No. 2).

75 mg
Each round, orange, biconvex, film-coated tablet, engraved "75" on one side, contains amitriptyline HCl 75 mg. Nonmedicinal ingredients: microcrystalline cellulose, croscarmellose sodium, magnesium stearate, colloidal silicon dioxide, hydroxypropyl methylcellulose, polyethylene glycol, titanium dioxide, carnauba wax, and Sunset Yellow AL Lake 40%.

How should I use this medication?

The usual starting dose of amitriptyline for depression in adults is 25 mg 3 times a day. The dose of amitriptyline is usually started low and increased slowly as prescribed by the doctor until the medication is at a dose that is appropriate and effective. After symptoms improve, the dose may be reduced to the lowest amount that will relieve symptoms. 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.

Many things can affect the dose of a 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 important to take this medication exactly as prescribed by your doctor. If you miss a dose, take it as soon as possible and continue with your regular schedule. If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule. Do not take a double dose to make up for a missed one. If you are not sure what to do after missing a dose, contact your doctor or pharmacist for advice.

Store this medication at room temperature, protect it from light and moisture, and keep it out of the reach of children.

Do not dispose of medications in wastewater (e.g. down the sink or in the toilet) or in household garbage. Ask your pharmacist how to dispose of medications that are no longer needed or have expired.

Who should NOT take this medication?

Amitriptyline should not be taken by anyone who:

  • is allergic to amitriptyline or to any of the ingredients of the medication
  • is taking an MAO inhibitor (e.g., phenelzine, tranylcypromine) or has taken one in the past 14 days
  • has a history of an allergic reaction to any of the antidepressants from the tricyclic antidepressant family (e.g., nortriptyline, desipramine, imipramine)
  • has acute congestive heart failure
  • has recently had a heart attack

What side effects are possible with this medication?

Many medications can cause side effects. A side effect is an unwanted response to a medication when it is taken in normal doses. Side effects can be mild or severe, temporary or permanent. 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 doctor.

The following side effects have been reported by at least 1% of people taking this medication. Many of these side effects can be managed, and some may go away on their own over time.

Contact your doctor if you experience these side effects and they are severe or bothersome. Your pharmacist may be able to advise you on managing side effects.

  • constipation
  • dizziness
  • drowsiness
  • dry mouth
  • flushing
  • headache
  • increased or decreased appetite
  • low blood pressure
  • nausea
  • tiredness or weakness (mild)
  • unpleasant taste
  • vision problems (e.g., blurred vision)
  • weight gain

Although most of the side effects listed below don't happen very often, they could lead to serious problems if you do not check with your doctor or seek medical attention.

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

  • agitation
  • anxiety
  • confusion
  • decreased or increased sexual ability
  • decreased or increased sweating
  • difficulty speaking
  • disorientation
  • eye pain
  • fast or irregular heartbeat
  • hallucinations
  • increased sensitivity to sunlight
  • irritability
  • loss of balance control
  • mask-like face
  • nervousness or restlessness
  • nightmares
  • numbing or tingling of the fingers or toes
  • problems urinating
  • ringing or buzzing in the ears
  • shuffling walk
  • skin rash or itching
  • tremors or shakiness
  • trouble sleeping
  • vomiting

Stop taking the medication and seek immediate medical attention if any of the following occur:

  • seizures
  • symptoms of a severe allergic reaction (e.g., swelling of face and tongue, difficulty breathing, hives)

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.

Are there any other precautions or warnings for this medication?

Before you begin using a medication, be sure to inform your doctor of any medical conditions or allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. These factors may affect how you should use this medication.

Drowsiness/reduced alertness: Amitriptyline may reduce mental 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.

Heart diseases: Tricyclic antidepressant medications such as amitriptyline can cause abnormal heart rhythms, particularly when taken in high doses. People with a history of heart disease and seniors should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Mania or hypomania: Amitriptyline may cause activation of mania or hypomania. People with a history of bipolar disorder should be closely monitored by their doctor while using this medication.

Medical conditions: People with the following conditions should discuss with their doctor how this medication may affect their medical condition, how their medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed:

  • benign prostatic hyperplasia (enlarged prostate)
  • certain blood disorders
  • increased eye pressure
  • reduced liver function
  • narrow-angle glaucoma
  • seizures
  • urinary retention

Suicidal or agitated behaviour: People taking antidepressants such as amitriptyline may feel agitated (restless, anxious, aggressive, emotional, trouble sleeping, and feeling not like themselves), or they may want to hurt themselves or others. If you notice any changes in mood, behaviours, thoughts, or feelings in yourself or someone who is taking this medication, contact a doctor immediately. Your doctor will monitor you closely for behaviour changes, especially at the start of treatment or when your dose is increased or decreased.

Surgery: Using amitriptyline before, during, and after surgery may increase the risk of developing abnormal heart rhythms. The risks and benefits of continuing amitriptyline during elective surgery should be discussed with your doctor. Your doctor may recommend to stop or reduce the dose of amitriptyline several days prior to the scheduled surgery.

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

Withdrawal: Stopping this medication abruptly after taking it for a long time may produce nausea, headache, and malaise. Gradual dosage reduction has been reported to produce (within 2 weeks) transient symptoms including irritability, restlessness, and dream and sleep disturbance. Experiencing these symptoms does not mean you are addicted. Do not suddenly stop taking this medication if you have been taking it for a while. If you are to stop taking this medication, contact your doctor, who will advise you on how to gradually stop this medication.

Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.

Breast-feeding: This medication passes into breast milk. If you are a breast-feeding mother and are taking amitriptyline, it may affect your baby. Talk to your doctor about whether you should continue breast-feeding.

Children: The safety and effectiveness of using this medication have not been established for children under 12 years of age.

What other drugs could interact with this medication?

There may be an interaction between amitriptyline and any of the following:

  • acetylsalicylic acid (ASA)
  • alcohol
  • alfuzosin
  • altretamine
  • amiodarone
  • anticholinergic medications (e.g., atropine, oxybutynin)
  • antifungals (e.g., fluconazole, itraconazole, ketoconazole)
  • antihistamines
  • barbiturates (e.g., butalbital, phenobarbital)
  • beta-2 agonists (e.g., salmeterol, formoterol, fenoterol, terbutaline)
  • bupriopion
  • carbamazepine
  • chloroquine
  • cholinesterase inhibitors (e.g., donepezil, galantamine, rivastigmine)
  • cimetidine
  • cinacalcet
  • ciprofloxacin
  • clonidine
  • decongestant nasal sprays (e.g., oxymetazoline, phenylephrine, naphazoline)
  • delavirdine
  • desmopressin
  • divalproex
  • dronedarone
  • duloxetine
  • guanethidine
  • isoniazid
  • levofloxacin
  • lithium
  • MAO inhibitors (e.g., phenelzine, tranylcypromine)
  • methylphenidate
  • moxifloxacin
  • nilotinib
  • nonsteroidal anti-inflammatory drugs (NSAIDs; e.g., celecoxib, diclofenac, ibuprofen, naproxen)
  • opioid analgesics (e.g., morphine)
  • other medications that can cause sedation (e.g., sedatives, sleeping pills, anaesthetics)
  • paroxetine
  • phenytoin
  • propafenone
  • propoxyphene
  • protease inhibitors for HIV (e.g., ritonavir, lopinavir, tipranavir)
  • quinidine
  • quinine
  • rifabutin
  • rifampin
  • selective serotonin reuptake inhibitors (SSRIs; e.g., citalopram, fluoxetine, fluvoxamine, sertraline)
  • St. John's wort
  • stimulant medications (e.g., appetite suppressants, epinephrine, norepinephrine)
  • terbinafine
  • tetrabenazine
  • thioridazine
  • tizanidine
  • tramadol
  • trazodone
  • valproic acid
  • warfarin
  • yohimbine
  • ziprasidone

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. 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 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.