Doxepin - oral

Patient Medicine Information
Why do I need this medicine?
Doxepin is used to treat depression.

It can also be used to treat people who experience difficulty sleeping (insomnia).

This medicine may be used to treat other conditions as decided by your doctor.
How do I take this medicine?
Take Doxepin exactly as directed by your doctor or according to the instruction on the label. Do not take more or less than instructed by your doctor.

Ask your doctor or pharmacist about whether you should take this medicine with or without food. Different brands of Doxepin may be taken differently.

Try to take it at the same time each day.

This medicine is available as a capsule, tablet, or oral solution.

If you are taking the capsule or tablet, swallow it whole with a glass of water. Do not divide, chew or crush the capsule or tablet.

If you are taking the oral solution, use the dropper supplied with each bottle to measure out your dose. The oral solution should be mixed with about 120 mL of water, whole or skimmed milk, or orange, grapefruit, tomato, prune or pineapple juice before administration. Once it is mixed, drink it immediately. Do not mix Doxepin oral solution with carbonated “fizzy” drinks.

The dose of this medicine will be decided by your doctor. Your doctor will advise you on the treatment timeframe depending on your response to the medication.

Doxepin must be taken regularly for it to be effective. Continue taking this medicine even when you feel better. Do not stop taking it unless instructed otherwise, as stopping it suddenly could worsen your condition.
What should I do if I have forgotten to take this medicine?
Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and return to your normal dosing schedule.

DO NOT double a dose under any circumstances.

If you often forget to take your medicine, let your doctor and pharmacist know.
When should I not use this medicine?
Alert your doctor if you have the following conditions:
  • mood disorder e.g. mania (feeling highly excited, being over-active and easily irritated or distracted)
  • glaucoma (increased pressure in the eyes)
  • urinary retention (difficulty passing urine)
  • severe liver disease
as Doxepin may not be suitable for you.

Do not take this medicine if you are breastfeeding.

Do not take Doxepin if you are currently taking or have taken a medicine that is used to treat depression known as a monoamine oxidase inhibitor (MAOI) such as isocarboxazid, phenelzine and tranylcypromine within 14 days of stopping the MAOI.
What should I take note of while taking this medicine?
Inform your doctor if you have the following conditions:
  • bipolar disorder (mood changes between feeling very high and very low)
  • with or a history of epilepsy (fits or seizures)
  • conditions predisposing to fits or seizures e.g. brain damage, alcoholism, head trauma
  • heart disease e.g. recent heart attack, heart block, stroke
  • slow bowel movement or when the bowel does not work properly
  • shallow breathing during sleep (sleep apnoea)
  • enlarged prostate gland
  • diabetes
  • thyroid disease
  • mild to moderate liver disease
  • kidney disease
Let your doctor know if you are pregnant.

Be sure to check with your doctor or pharmacist before giving this medicine to an elderly.

Medicines for depression such as Doxepin may increase the risk of suicidal thoughts and behaviour. As depression and some psychiatric disorders are themselves associated with an increased risk of suicide, it is important for you or your family members to monitor your condition especially at the start of treatment and if your dosage is still being adjusted. If you experience new or sudden changes in mood, behaviour, thoughts or feelings or a worsening of your depression with suicidal thoughts or attempts, harm to self or harm to others, contact your doctor immediately.

If you are going to have an operation, including minor surgery and dental work, inform your doctor or dentist that you are taking this medicine.

Notify your doctor if you have recently undergone electroshock therapy (also known as electroconvulsive therapy or ECT).

Some genetic traits can affect an individual’s response to this medicine. Certain enzymes called CYP2D6 and CYP2C19 are involved in the breakdown of Doxepin in the body. Individuals who are known as poor metabolisers of CYP2D6 and CYP2C19 may experience enhanced side effects of this medicine (e.g. dry mouth, drowsiness, blurred vision). Although not routinely done, your doctor may advise you to undergo genetic testing to check if Doxepin is best suited for you. If you know you have this gene type, inform your doctor.

Keep your appointments with your doctor. Your doctor needs to monitor your condition and check your response to the medication regularly.
  • You may need to have routine tests (e.g. blood sugar or sodium levels, liver function) before and during your treatment with this medicine. Your doctor will advise you about how often you will need to have these tests.
  • Your doctor may also need to perform an ECG (test used to record the electrical activity of the heart) and regularly monitor your blood pressure, heart rate and weight.
  • It is important for you to monitor your condition especially at the start of treatment and if your dosage is still being adjusted. Monitor for signs and symptoms of suicidal thoughts or actions, and unusual changes in behaviour may be needed while you are being treated with Doxepin.
What lifestyle changes should I make to cope with depression?

Regular exercise and eating a healthy diet will help increase energy and hormones in the body such as serotonin, endorphins and other feel-good chemicals that minimise mood swings. Get enough sleep, as lack of sleep may cause irritability, moodiness, sadness, and tiredness.
What side effects could I experience?
Doxepin may cause drowsiness. If affected, do not drive or take part in any activity in which you need to be alert.

This medicine may cause your blood pressure to fall suddenly when you get up from a sitting or lying down position and you may feel giddy. To minimise this problem, stand up slowly.

It may also cause abnormal activities during sleep, such as driving, cooking, eating and walking while you are still asleep. Alert your doctor quickly if this happens.

Other side effects include any of the following: headache, dizziness, blurred vision, dry mouth, constipation, nausea, vomiting, diarrhoea, taste changes, loss of appetite, weight gain, tiredness, involuntary shaking of the hands or legs, numbness or tingling sensation in the hands and feet, sensitivity to sunlight, sweating, and hair loss.

Some side effects may need immediate medical help. Alert your doctor immediately if you experience any of the following:
  • having thoughts of self-harm
  • unusual changes in mood or behaviour (being too depressed, agitated, confused or having compulsive and impulsive behaviour)
  • fast or irregular heartbeat 
  • unexplained bone pain or tenderness, swelling or bruising
  • unusual bleeding or bruising, frequent and persistent sore throat with fever
  • rashes, breathlessness, swollen mouth or eyes
Inform your doctor if any of these side effects do not go away or are severe, or if you experience other side effects.
Can I take this with other medicines?
Do not take Doxepin if you are currently taking or have taken a medicine to treat depression known as a monoamine oxidase inhibitor (MAOI) such as isocarboxazid, phenelzine and tranylcypromine within 14 days of stopping the MAOI.

Inform your doctor and pharmacist if you are taking any of these medicines:
  • medicines for high blood pressure e.g. clonidine, guanethidine, bethanidine, debrisoquine
  • medicines for heart disease e.g. quinidine, glyceryl trinitrate
  • medicines to treat depression e.g. fluoxetine, sertraline, paroxetine, citalopram
  • medicines for epilepsy (fits or seizures) e.g. phenobarbital, amobarbital
  • cimetidine (gastric medicine)
  • tolazamide (medicine for diabetes)
  • St. John’s wort (herbal medicine)
This list does not include all medicines that interact with Doxepin.

Always notify your doctor and pharmacist if you are taking any other medicines, including herbal tonics such as traditional Chinese medicines, supplements and medicines that you buy without a prescription.
What special dietary instructions should I follow?
Avoid alcohol.
How should I store this medicine?
Store in a cool, dry place away from the reach of children. Protect from light.

Medicines must not be used past the expiry date.
This information is independently developed by MIMS based on doxepin - oral and is provided for your reference only. It is not a replacement for and should only be used in conjunction with full consultation with a licensed healthcare professional, the information provided by your pharmacist and/or the manufacturer of the medication. It may not contain all the available information you require and cannot substitute professional medical care, nor does it take into account all individual circumstances. Although great effort has been made to ensure content accuracy, we shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2021 MIMS. All rights reserved. Powered by
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