Medication Guide
Doxepin (Silenor, Sinequan) Side Effects and Uses
A plain-language guide to Doxepin, a Tricyclic antidepressant (TCA). Learn how it helps, what it treats, how to take it and which side effects to know about.
Quick answer. Doxepin (Silenor) is a Tricyclic antidepressant (TCA). Common doxepin side effects include sleepiness or next-morning grogginess, dry mouth, constipation and blurred vision. The rare but serious ones, and when to get help, are listed under doxepin side effects below. Never stop or change your dose on your own.
How Doxepin Can Help You
Doxepin is a tricyclic antidepressant. It acts very differently at different doses. Very low doses are sold as Silenor. At these doses, it works mainly as an antihistamine. It helps people stay asleep through the night. It is FDA approved for trouble staying asleep. It is not a controlled substance.
At higher doses, it treats depression and anxiety. Its strong antihistamine effect also helps chronic itch and hives.
For sleep, the effect often starts in the first few nights. For depression or anxiety, improvement follows the usual four to eight weeks. The low-dose and higher-dose forms act almost like different medicines. Your prescriber will tell you which form and strength fits your goal.
Uses for Doxepin
- Trouble staying asleep (low-dose Silenor)
- Major depressive disorder
- Anxiety
- Chronic hives and itching (off-label by mouth, and a cream for some skin conditions)
- Insomnia in people who need to avoid habit-forming sleep aids
- Depression with poor sleep or anxiety
How to Take Doxepin
Your prescriber decides your dose and form. For sleep, Silenor is taken within 30 minutes of bedtime. Do not take it within three hours of a meal. Food delays its effect and adds to next-day drowsiness. For depression or anxiety, the capsules are usually taken at bedtime.
Take your dose at the same time each night. Allow a full night of sleep to limit grogginess. If you miss a dose, skip it and do not double up. Do not stop doxepin suddenly, mostly at antidepressant doses. Follow your prescriber's taper plan. Take it exactly as prescribed. Store it safely, as with all tricyclics.
Doxepin Side Effects
Common Side Effects
- Sleepiness or next-morning grogginess
- Dry mouth
- Constipation
- Blurred vision
- Dizziness on standing
- Weight gain at higher doses
- Nausea
- Trouble starting to urinate
Serious: Get Medical Help Promptly
- New or worse suicidal thoughts, mostly in people under 25 (boxed warning)
- Heart rhythm changes at antidepressant doses, with a pounding heartbeat or fainting
- Dangerous in overdose at higher doses, so take it exactly as prescribed and store it safely
- Complex sleep behaviors, such as sleepwalking or sleep-driving
- Severe confusion, mostly in older adults
- Angle-closure glaucoma, with sudden eye pain or vision changes
How Doxepin Works
Doxepin blocks histamine very strongly, even in tiny amounts. Histamine helps keep the brain awake. Blocking it helps you stay asleep. That is the main action behind low-dose Silenor.
At higher doses, it also acts on serotonin and norepinephrine, like other tricyclics. That is when it treats depression and anxiety. Classic TCA side effects also become more likely then. Examples are dry mouth and constipation.
Before You Start Doxepin
Doxepin must never be taken with an MAOI antidepressant. It is not for people with certain eye or bladder problems. Your prescriber will ask about these. Alcohol, sleep aids and other sedating drugs add to drowsiness. They also raise the risk of falls. Some medicines, such as cimetidine, can raise doxepin levels.
Tell your prescriber about heart problems, seizures, liver disease and sleep apnea. Also share any history of bipolar disorder. Do you do things while not fully awake, such as sleepwalking? Stop and call your prescriber. If you are thinking about harming yourself, call or text 988, or call 911. Learn about insomnia care by telehealth in California.
Is Doxepin Right for You?
Only a full evaluation with a prescriber can tell you if Doxepin fits your symptoms, history and goals. Harpal Singh, PMHNP-BC offers psychiatric evaluations and ongoing medication management by telehealth anywhere in California.
SCHEDULE AN APPOINTMENT CALL (888) 457-8124
Related Medication Guides
Other guides in the same group, written the same simple way. Being in one group does not mean you can swap one medicine for another.
- Citalopram (Celexa), SSRI antidepressant
- Desvenlafaxine (Pristiq), SNRI antidepressant
- Duloxetine (Cymbalta), SNRI antidepressant
- Escitalopram (Lexapro), SSRI antidepressant
- Fluoxetine (Prozac), SSRI antidepressant
- Fluvoxamine (Luvox), SSRI antidepressant
FAQ
Questions About Doxepin
How can the same drug be a sleep aid and an antidepressant?
It comes down to dose. In very low doses, doxepin mainly blocks histamine, which helps you stay asleep. Only at much higher doses do its serotonin and norepinephrine effects, and the usual tricyclic side effects, come into play.
Is low-dose doxepin habit-forming?
Low-dose doxepin is not a controlled substance and is not known to cause cravings. That makes it an option for long-term trouble staying asleep, including in older adults. Your prescriber still reviews it over time.
Why can't I take Silenor right after dinner?
Food slows how fast doxepin is absorbed. That pushes its peak effect into the morning and can leave you groggy. Taking it at least three hours after your last meal keeps the sleepiness at night.
Does doxepin help with itching?
Yes. Doxepin's strong antihistamine effect makes it useful for chronic hives and itching. A prescription cream is used for some itchy skin conditions. If itching is part of your picture, mention it, since one medicine may help more than one problem.
Who should be cautious with doxepin?
People with untreated narrow-angle glaucoma or severe trouble urinating should avoid it. Those with heart disease need follow-up at antidepressant doses. Older adults are more prone to confusion and falls, which is why very low doses are usually chosen for sleep.
How fast does low-dose doxepin work for sleep?
Many people notice better sleep within the first few nights. It works best for staying asleep rather than falling asleep. Tell your prescriber if it does not help after a fair trial.
Can I drink alcohol with doxepin?
No, it is best to avoid it. Alcohol adds to sleepiness and raises the risk of falls and slowed breathing. At higher doses, the mix can be dangerous.
Will doxepin make me groggy in the morning?
It can, mostly at first or if you do not get a full night of sleep. Taking it at the right time and away from meals helps. If grogginess lasts, tell your prescriber, who may change the plan.