9 Doxepin Side Effects You Should Know About

Doxepin (Sinequan) is a tricyclic antidepressant (TCA) used to treat depression and anxiety. It’s also approved for insomnia under the brand name Silenor. TCAs are known for causing side effects, and doxepin is no exception. Here we’ll discuss what to expect when you start taking it.

Doxepin side effects at a glance

Listed below are the common and rare side effects reported in clinical trials of TCAs, including doxepin capsules and tablets. (Doxepin also comes in a topical cream that isn’t discussed in this article.)

Keep in mind that everyone responds to medication differently. It’s best to talk to your healthcare team if you think you’re experiencing a doxepin side effect — even if it’s not on this list.

Promotion disclosure

Doxepin

Avg retail price

$26.99(Save 69.10%)

GoodRx discount

$8.34

See all discounts

How it works

Use GoodRx to find medications, pharmacies, and discounts.

GoodRx discounts can help you pay less for your prescription.

Bring your free coupon or savings card to the pharmacy.

Common doxepin side effects:

• Drowsiness

• Dizziness

• Dry mouth

• Constipation

• Trouble peeing

• Blurry vision

• Nausea and vomiting

• Upper respiratory infection

• Sweating

• Weight changes

• Enlarged breasts

• Changes in taste

• Changes to sex drive

• Blood pressure changes

• Withdrawal symptoms (if stopped abruptly)

Rare but serious doxepin side effects:

• Suicidal thoughts

• Changes to mood and behavior

• Irregular or fast heartbeat

• Skin rash

• Seizures

• Tremor (shakiness)

• Hallucinations

• Low blood cell counts

Let’s look more closely at nine possible doxepin side effects and how to manage them.

1. Dizziness and drowsiness

Two of the most common doxepin side effects are dizziness and drowsiness. While feeling drowsy is a helpful side effect if you’re taking doxepin to sleep, it can be bothersome if it affects you during the day.

Doxepin can also cause a drop in blood pressure when you sit or stand up quickly (orthostatic hypotension). You may feel dizzy or lightheaded when this happens. Taking your time when changing positions and using a wall or furniture for support can help manage this side effect.  

Often, dizziness and drowsiness will go away over time as your body adjusts to doxepin. If you’re taking doxepin once a day, taking it at bedtime can help lessen daytime drowsiness. But you should avoid eating within 3 hours of your bedtime dose. Taking doxepin with food at night raises the chance of the next-day drowsiness. 

You may want to avoid activities that require alertness, such as driving or operating machinery, until you know how doxepin affects you. It’s also best to avoid alcohol while taking doxepin, since it can magnify these side effects.

If dizziness or drowsiness worsen or interfere with your daily life, let your healthcare team know. They may decide to lower your doxepin dose or switch you to a different medication.

Good to know: In rare cases, you may perform activities such as eating, making phone calls, or even driving while you’re asleep after taking doxepin. This isn’t common, but it can be dangerous. And you may not remember that it happened. If you notice any signs of this side effect, talk to your prescriber right away. Doxepin may not be the best treatment for you.

2. Dry mouth

Another common doxepin side effect is dry mouth. That’s because doxepin is an anticholinergic medication. It blocks the activity of a chemical called acetylcholine, which can lead to a number of side effects, including dry mouth. 

Drinking plenty of water and chewing sugar-free gum can help you manage dry mouth. You can also try an over-the-counter (OTC) saliva substitute, such as Biotene or BioXtra.

Dry mouth can make you more prone to cavities and gum disease. So it’s key to maintain good oral health and visit your dentist regularly.

3. Constipation

Constipation is another doxepin side effect related to its anticholinergic effects. It may improve as your body adjusts to the medication, but in the meantime, eating a high-fiber diet, drinking plenty of water, and staying physically active are all ways to help prevent and manage constipation.

If needed, an OTC stool softener or laxative can also help with constipation. But if you need them for more than 7 days in a row or they aren’t working, be sure to seek medical care. Untreated constipation can lead to more serious health issues.

4. Trouble peeing

Some people taking doxepin may experience difficulty peeing. As with dry mouth and constipation, this is related to its anticholinergic effects. 

This side effect may improve once your body adjusts to doxepin. But if it doesn't improve, you’re unable to pee, or you’re producing less urine than usual, let your prescriber know. These symptoms can lead to more serious problems if they aren’t addressed.

5. Nausea and taste changes

Doxepin can sometimes cause changes in taste. This could be a metallic or bitter taste in your mouth or a general change in how foods taste to you. Doxepin can also cause nausea, which can make food seem less desirable. 

Drinking plenty of water, eating smaller, more frequent meals, and maintaining good oral hygiene can help manage this side effect. But if it doesn’t go away or keeps you from enjoying your food, let your healthcare team know.

6. Weight changes

Doxepin, like many other antidepressants, may cause weight gain. This can be frustrating, especially if maintaining a healthy weight is already a concern for you.

There are a number of things you can try to keep weight gain caused by doxepin to a minimum. Getting enough sleep, eating a healthy diet, and exercising regularly are all great places to start. But if doxepin’s effect on your weight is bothersome, talk to your prescriber about other antidepressant or sleep medications that aren’t as likely to cause this side effect.

7. Sexual side effects

Like other antidepressants, doxepin can sometimes cause sexual side effects. This may include decreased sex drive, erectile dysfunction, or difficulty achieving orgasm. And it can affect both men and women.

Keep in mind that depression can also contribute to sexual issues, so they may also be a sign that doxepin isn’t working to fully treat your symptoms.

Communicating openly with your partner about what you're experiencing may help lessen some of the stress surrounding this side effect. And don’t be ashamed to talk to your healthcare team about these side effects, too. They can adjust your dosage or recommend an alternative medication that doesn’t cause the same issues for you.

8. Enlarged breasts

Enlarged breasts, especially in men, are another possible doxepin side effect. While not harmful, enlarged breasts can be uncomfortable and may make you feel self-conscious. 

In most cases, this side effect is temporary and will go away once you stop taking doxepin. If it’s bothersome, ask your prescriber about an alternative medication you can try. Keep in mind that breast changes can also be caused by breast cancer (even in males). So it’s best to have any breast changes checked out by a healthcare professional to be safe.

9. Suicidal thoughts

One of the most serious doxepin side effects is an increased risk of suicidal thoughts. The FDA requires all antidepressant medications to have a boxed warning (their most serious type of drug warning) about this side effect. 

This risk is highest in the first few months of treatment or after a change in dosage. Let your healthcare team know right away if you notice sudden or negative changes in your mood while taking doxepin.

If you or someone you know is having thoughts of suicide, you’re not alone, and help is available. Call the 988 Suicide & Crisis Lifeline at 988, or text HOME to 741-741 to reach the Crisis Text Line.

When should you seek medical care for doxepin side effects?

Many common doxepin side effects are mild and often get better after a few weeks of treatment. This includes dizziness and drowsiness, dry mouth, and constipation. In the meantime, you can take steps to manage them at home.

But if at any time side effects are worsening or bothersome, let your healthcare team know. They can suggest ways to manage them or make changes to your medication if needed. If at any time you experience symptoms that seem severe or life-threatening, seek emergency care.

Why trust our experts?

Written by:

Alex Evans, PharmD, MBA

Alex Evans, PharmD, MBA, has been a pharmacist for 12 years. His first job was floating in a community chain pharmacy.

Edited by:

Stacia Woodcock, PharmD

Stacia Woodcock, PharmD, is a pharmacy editor for GoodRx. She earned her Doctor of Pharmacy degree from the University of Kentucky and is licensed in New York and Massachusetts.

Reviewed by:

Daphne Berryhill, RPh

Daphne Berryhill, RPh, has two decades of experience as a clinical pharmacist. She spent most of her career in the Chicago area practicing in-home infusion.

Our editorial standards

Meet our experts