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

Doxepin belongs to the group of medications known as hypnotics . It is used to treat sleeping problems for people who are having trouble staying asleep. Exactly how doxepin helps with sleep is unknown, but researches believe it affects the level of a certain chemical substance in the brain. Doxepin is also used in higher doses to treat depression.

This medication may be available under multiple brand names and/or in several different forms. Any specific brand name of this medication may not be available in all of the forms or approved for all of the conditions discussed here. As well, some forms of this medication may not be used for all of the conditions discussed here.

Your doctor may have suggested this medication for conditions other than those listed in these drug information articles. 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?

Each blue oval shaped tablet debossed with "3" on one side and "SP" on the other contains doxepin 3 mg. Nonmedicinal ingredients: microcrystalline cellulose, colloidal silicon dioxide, magnesium stearate, D&C lake yellow and FD&C lake blue.

6 mg
Each green oval shaped tablet debossed with "6" on one side and "SP" on the other contains doxepin 6 mg. Nonmedicinal ingredients: microcrystalline cellulose, colloidal silicon dioxide, magnesium stearate, D&C lake yellow and FD&C lake blue.

How should I use this medication?

The recommended adult daily dose of doxepin is 6 mg once daily, taken 30 minutes before bedtime. A 3 mg once daily dose may be needed for some people. Do not take doxepin within 3 hours of a meal.

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, 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?

Doxepin should not be taken by anyone who:

  • is allergic to doxepin or to any of the ingredients of the medication
  • is allergic to any other dibenzoxepin compounds
  • has untreated narrow-angle glaucoma
  • has taken a MAO inhibitor (e.g., phenelzine, tranylcypromine) within the last 14 days
  • has severe urinary retention (unable to urinate)

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.

  • dizziness
  • drowsiness
  • dry mouth
  • headache
  • nausea
  • tiredness
  • unpleasant taste

Although most of these 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:

  • anxiety
  • confusion
  • fast heartbeat
  • hallucinations
  • nervousness or restlessness
  • sleepwalking or doing other activities while asleep (e.g., eating, driving)
  • thoughts of death or suicide
  • vomiting

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

  • 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.

Behaviour changes:This medication may worsen symptoms of depression, including thoughts of suicide or wanting to harm others. It may also cause agitated or aggressive behaviour. If you experience these symptoms or any other behaviour change while taking this medication, contact your doctor immediately.

Family members or caregivers of people who are taking this medication should contact the person's doctor immediately if they notice unusual behaviour changes.

Drowsiness/reduced alertness: Doxepin can cause drowsiness and decreased mental alertness. Do not operate heavy machinery or drive after taking this medication. Do not use doxepin if you drink alcohol.

Liver problems: If you have liver problems, discuss with your doctor how this medication may affect your medical condition, how your medical condition may affect the dosing and effectiveness of this medication, and whether any special monitoring is needed.

Performing activities while not fully awake: People taking doxepin may perform activities such as sleepwalking, driving, preparing and eating food, and making phone calls while not fully awake and unaware of their actions. The next morning, they may not remember what happened. This may be more likely to occur if you use alcohol or other sedative medications. If you discover this has happened to you, contact your doctor immediately.

Sleep apnea: The safety of using doxepin for people with sleep apnea has not been established.

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: Doxepin passes into breast milk. Doxepin is not recommended for use by women who are breast-feeding.

Children: The safety and effectiveness of using this medication have not been established for children under the age of 18.

Seniors: Seniors may be more likely to experience drowsiness or confusion while taking this medication.

What other drugs could interact with this medication?

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

  • acetylsalicylic acid (ASA)
  • alcohol
  • alfuzosin
  • altretamine
  • amiodarone
  • anticholinergic medications (e.g., atropine)
  • barbiturates (e.g., phenobarbital)
  • benzodiazepines (e.g., diazepam, lorazepam)
  • beta-2 agonists (e.g., salmeterol, formoterol, fenoterol, terbutaline)
  • bupropion
  • carbamazepine
  • certain medications for diabetes (e.g., glyburide, gliclazide)
  • chloroquine
  • cholinesterase inhibitors (e.g., donepezil, galantamine, rivastigmine)
  • cimetidine
  • cinacalcet
  • ciprofloxacin
  • clonidine
  • decongestant nasal sprays (e.g., oxymetazoline, phenylephrine, naphazoline)
  • delavirdine
  • desmopressin
  • disopyramide
  • divalproex
  • dronedarone
  • duloxetine
  • guanethidine
  • ipratropium
  • lithium
  • MAO inhibitors (e.g., phenelzine, moclobemide)
  • methyldopa
  • methylphenidate
  • metoclopramide
  • nilotinib
  • nonsteroidal anti-inflammatory drugs (NSAIDs; e.g., celecoxib, diclofenac, ibuprofen, naproxen)
  • other medications that can cause sedation (e.g., sedatives, sleeping pills, anaesthetics)
  • paroxetine
  • pimozide
  • procainamide
  • protease inhibitors for HIV (e.g., ritonavir, lopinavir, tipranavir)
  • quinidine
  • quinine
  • rifabutin
  • rifampin
  • sotalol
  • SSRI antidepressants (e.g., fluoxetine, fluvoxamine)
  • stimulant medications (e.g., appetite suppressants, amphetamines, epinephrine, norepinephrine)
  • St. Johns Wort
  • terbinafine
  • tetrabenazine
  • tiotropium
  • tramadol
  • "triptan" medications (e.g., sumatriptan, almotriptan)
  • valproic acid
  • warfarin
  • yohimbine

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.