Doxepin: Side Effects, Uses, Dosage, & More

What Is Doxepin?

Doxepin is a generic medication used to treat depression, anxiety disorders, and insomnia. It is part of the drug class of tricyclic antidepressants.¹ Doxepin works by increasing serotonin and norepinephrine in the brain. By increasing these levels, individuals can see improvements in regulating mood and improving sleep. Doxepin is approved by the FDA for use in major depressive disorder, insomnia, and anxiety disorders.²

How Does Doxepin Work?

Doxepin works by helping to balance certain chemicals in the brain, specifically norepinephrine and serotonin. By enhancing these chemicals, doxepin can alleviate depression symptoms, anxiety symptoms, and insomnia.

What Is Doxepin Used to Treat?

Doxepin is FDA-approved to treat insomnia, major depressive disorder, and anxiety. FDA approval signifies that the medication has undergone rigorous testing and has been found safe and effective for a specific condition.

Doxepin is FDA-approved to treat the following conditions:^{1, 3}

• Depression or anxiety in patients with psychoneurosis
• Depression or anxiety associated with alcoholism
• Depression or anxiety with organic disease
• Psychotic depressive disorders with associated anxiety
• Involutional depression
• Manic depressive disorder
• Insomnia

Zonalon, a brand name version of doxepin, is also available as a topical cream for treating skin conditions such as  pruritus/itching and lichen simplex chronicus. This brand will not be covered in this article.

However, healthcare providers may choose to prescribe doxepin off-label for conditions not approved by the FDA. This is done based on their clinical judgment if the provider believes the medication will still benefit an individual.

Off-label uses of doxepin include:^{2, 3}

• Anxiety
• Neuropathic pain/chronic pain
• Treatment-resistant depression

Common Side Effects of Doxepin

Doxepin can cause a variety of side effects. The most common side effects are typically mild and resolve as the body adjusts to the medication. These side effects are often due to the medication’s impact on the brain and the rest of the body.

Common side effects of doxepin include:^{1, 2}

• Drowsiness
• Weight gain
• Dry mouth
• Constipation
• Dizziness

*All medications, including doxepin, can cause side effects which can be mild or serious. This is not a comprehensive list of all possible side effects. You should talk with your doctor about any questions you have and to understand the potential side effects and benefits of any medication.

Serious Side Effects of Doxepin

Although most side effects are mild and resolve over time, some can be serious or persistent and require immediate medical attention. The medication can cause severe side effects that impact the heart, brain, and urinary system. If these severe side effects occur, immediate medical attention is required.

Serious side effects of doxepin include:^{1, 2}

• Inability to pass urine
• Suicidal thoughts and behaviors
• Hallucinations
• Confusion
• Chest pain
• Irregular heartbeat
• Seizures

*All medications, including doxepin, can cause side effects which can be mild or serious. This is not a comprehensive list of all possible side effects. You should talk with your doctor about any questions you have and to understand the potential side effects and benefits of any medication.

Doxepin Warnings & Precautions

Before taking doxepin, it’s important to be aware of its associated warnings and precautions. Depending on their health history, some individuals may be at a higher risk for severe side effects. These side effects may require immediate medical attention.

Warnings and precautions for doxepin include:¹

• Avoid doxepin if you are diagnosed with bipolar disorder: Individuals with bipolar disorder have an increased risk of mixed/manic episodes when taking antidepressants such as doxepin.
• Avoid doxepin if you are diagnosed with glaucoma: Doxepin can increase the risk of a sudden worsening of glaucoma.
• Boxed warning – increased risk of suicidality: Doxepin can increase the risk of suicidal thoughts and behaviors in certain people. This risk is higher in individuals 24 years and younger.
• Drug interactions: Doxepin can interact with many other medications, leading to an increased risk of side effects.
• Risk during pregnancy: The risk of taking Doxepin during pregnancy is unknown. The decision to continue taking doxepin during pregnancy should be made in conjunction with a healthcare professional.
• Risk while breastfeeding: Doxepin is not recommended during breastfeeding due to its potential sedation effects on the fetus. ⁴

There may be additional warnings or precautions with this medication. Talk with your healthcare provider about all risks before you start taking this medication.

Doxepin Dosages for FDA-Approved Treatment

Dosages for doxepin can vary significantly from person to person due to various factors, such as age, weight, health condition being treated, medical history, and response to the medication. The typical dosage for depression is 75 mg to150 mg daily. This can be taken once or twice per day. For insomnia, the typical dosage is 3 mg to 6 mg before bedtime.

When used for treating depression, doxepin is often started at 25 mg taken at bedtime. This dose can then be increased by 25 mg every 3-7 days, depending on the individual response. The maximum dose for depression is 300 mg per day.

When treating insomnia, the medication can be started at 3 or 6 mg, taken 30 minutes before bedtime. The maximum dose for insomnia is 6 mg.

Doxepin Forms & Strengths

Doxepin is available in various forms and strengths to accommodate different individual needs. It comes in oral formulations such as tablets and capsules with strengths that range from 3 mg to 150 mg. This medication does not come in extended-release formulations, but it does come as an oral solution.

When determining the appropriate form and strength of doxepin, prescribers consider several factors. This will include the individual’s medical condition, age, weight, use of other medications, and medical history. Often, the lowest dose possible will be started to decrease the risk of side effects.

Doxepin is available in the following forms and strengths:^{1, 3}

• Capsules: 10 mg, 25 mg, 50 mg, 75 mg, 100 mg, 150 mg
• Tablets: 3mg, 6 mg
• Oral Solution: 10 mg/ml

How Long Does it Take for Doxepin to Start Working?

Doxepin may have immediate effects when treating insomnia or anxiety.³ For depression, however, the effects often take 2-4 weeks to be noticeable. If there is no effect by 6-8 weeks, the dose may need to be increased or the medication may need to be changed. The time it takes to notice effects will vary from person to person.

How Should I Take Doxepin?

Doxepin should always be taken as prescribed by your healthcare provider. The doxepin capsule or tablet should be swallowed whole. It can be taken with or without food.⁵ For the oral solution, it can be mixed in water, milk, or juice before taking it.

What Happens If I Miss a Dose of Doxepin?

If you miss a dose of doxepin, take the medication as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Never double your dose to make up for a missed one.

Can You Overdose on Doxepin?

You can overdose on doxepin. This typically occurs when too much is taken at once. You may also experience signs of overdose if doxepin is taken with other medications that interact with doxepin. Symptoms of a doxepin overdose may include irregular heartbeat, agitation, drowsiness, seizures, hallucinations, and coma.

What Should You Do If You Take Too Much Doxepin?

If you take too much doxepin, call the poison control helpline at 1-800-222-1222. However, seek immediate medical attention if severe symptoms occur, such as seizures, difficulty breathing, or coma.

What to Avoid When Taking Doxepin

When taking doxepin, it’s important to be aware of the potential interactions with other medications, substances, and herbs. These interactions can lead to an increased risk of side effects, which can be severe.

Six substances you should avoid while taking doxepin include:^{1, 3}

• Selective-serotonin reuptake inhibitors (SSRIs): Taking SSRIs with doxepin can increase the level of doxepin in the body, leading to an increased risk of side effects and a potential life-threatening condition called serotonin syndrome. This includes SSRIs such as fluoxetine, paroxetine, sertraline, and citalopram.
• Tricyclic antidepressants: Taking doxepin with other tricyclic antidepressants can increase the level of doxepin in the body, increasing the risk of side effects. Tricyclic antidepressants include amitriptyline, imipramine, and nortriptyline.
• Tramadol: Tramadol is a medication used to treat pain. Taking tramadol with doxepin can increase the risk of seizures.
• Cimetidine: Cimetidine is a medication used to treat heartburn. Taking cimetidine with doxepin can increase the level of doxepin in the body, leading to an increased risk of side effects.
• Methylphenidate: Methylphenidate is a medication used to treat ADHD. Taking methylphenidate with doxepin can lead to increased levels of doxepin in the body and an increased risk of side effects.
• Alcohol: Alcohol can enhance the level of drowsiness caused by doxepin.

This is not a comprehensive list of the possible interactions with doxepin. You should talk with your healthcare provider and your pharmacist about all prescription and over-the-counter medications, herbs, and supplements you take before starting doxepin.

How to Get a Prescription for Doxepin

Doxepin is only available through a prescription by a licensed healthcare provider. Typically, healthcare providers who can prescribe doxepin include primary care physicians, psychiatrists, and nurse practitioners. To obtain a prescription for doxepin, an individual must schedule an appointment with a healthcare provider to discuss symptoms, medical history, and alternative treatment options.

If someone needs to find a psychiatrist, there are several options. One option is to ask for a referral from a primary care physician. Additionally, health insurance plans may have directories of in-network providers. Virtual platforms are also available to provide the ability to see a psychiatrist remotely.

FAQs About Doxepin

Below are some frequently asked questions about doxepin.

Is Doxepin a Strong Sleeping Pill?

Doxepin can be effective for treating insomnia and may be an effective long-term option for insomnia.³ Because of its impact on the brain, doxepin can decrease wakefulness and prompt sleep. Its strength relative to other sleeping pills will vary from individual to individual.

Is Doxepin Better Than Xanax?

Doxepin and Xanax are typically used to treat different conditions. Xanax (alprazolam) is used in the treatment of generalized anxiety disorder and panic disorder. However, Xanax can be used off-label for sleep. While both medications can be effective, individuals may respond differently to these medications.

Is Doxepin the Same as Gabapentin?

Doxepin and gabapentin are distinct medications that impact the body and brain in different ways. Doxepin is a tricyclic antidepressant primarily used to treat depressive disorders, anxiety disorders, and insomnia. Gabapentin is a calcium channel blocker used to manage seizures and neuropathic pain conditions.

Can Doxepin Be Used During Pregnancy or While Breastfeeding?

Doxepin is generally not recommended during pregnancy, especially during the first trimester.³ The effects on a developing fetus are not clear, but doxepin does cross the placenta. Adverse effects, such as lethargy, withdrawal symptoms, and fetal malformations, have been reported.³ The decision to continue using doxepin during pregnancy should be made in conjunction with a healthcare provider.

Doxepin is excreted in breast milk and may cause drowsiness in breastfed infants. Generally, doxepin is not recommended while breastfeeding. However, one must weigh the benefits of breastfeeding and antidepressant treatment versus not breastfeeding and not continuing treatment.

Questions to Ask Your Healthcare Provider About Doxepin

If you are considering doxepin as a treatment option, you should start by discussing it with your doctor, psychiatrist, and therapist. Be prepared with a list of questions to ensure you understand the medication’s benefits, risks, and alternative options. If you are searching for a psychiatrist, one good option is online psychiatry services. These platforms are a convenient option to access mental health professionals from your home.

Questions to ask your care team about doxepin include:

• How safe is doxepin?
• How long will it take for me to adjust to taking doxepin?
• Am I at risk for more serious symptoms if I am already taking other medications?
• What is the best dosage to ensure fewer side effects?
• Are there any lifestyle changes I should consider while taking doxepin?
• When should I take doxepin?
• Can doxepin interact with other medications or substances that I am taking?
• Does my medical history make doxepin less suitable for me?
• How often should I follow up with you to monitor my progress?
• Are there any long-term effects or risks associated with doxepin?
• What should I do if I experience side effects?