Silenor Effective as an Insomnia Treatment

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The pharmaceutical drug Silenor (doxepin) is a tricyclic antidepressant that is also used as a hypnotic to initiate and maintain sleep. It was approved by the FDA for the treatment of insomnia in March 2010.

Silenor is touted by the manufacturer as a non-abusable option for insomnia relief and is not classified as a controlled substance by the DEA. As there seems to be a lack of abuse potential, it may be a good option for individuals concerned about becoming addicted to sleeping pills.

A pharmacist pulling open drawer of medication
Agnieszka Wozniak / Caiaimage / Getty Images


Silenor can be effectively used to treat the symptoms of insomnia or acute insomnia. It helps to initiate and maintain sleep by causing drowsiness. At higher doses, it is also used to treat anxiety and depression.

How It Works

It is not known precisely how Silenor works. It is believed to act on neurotransmitters, which are chemical messengers within the brain. It allows a specific neurotransmitter called histamine to build up in the spaces between nerve cells by blocking its uptake into the nearby cells.

Who Should Not Use It

Young people under 25 years old should not use this medication as there is an increased risk of suicide in those with major depression and other psychiatric disorders. Silenor should also not be used if you are recovering from a recent heart attack. If you have glaucoma or difficulties with urinary retention, it is recommended that you not use this medication.

Silenor should be used with caution if you have cardiovascular disease, seizures, thyroid problems, diabetes, asthma, Parkinson's disease, liver problems, or are elderly. Silenor may also not be appropriate if you have bipolar disease or schizophrenia, or if you are at risk for suicide.

Silenor should be avoided if you are pregnant or breastfeeding.

Silenor has the potential to interact with many other drugs, so your medications should be carefully reviewed by your healthcare provider before you start to take Silenor. Stopping the medication abruptly should be avoided.

Side Effects

There are many potential side effects of any drug. Although an individual would not be expected to experience most side effects — and may indeed not have any of them — some that may commonly occur with Silenor include:

  • Sleepiness
  • Dry mouth
  • Dizziness
  • Constipation
  • Blurred vision
  • Heart palpitations
  • Rapid heart rate
  • Incontinence
  • Increased appetite
  • Nausea or vomiting
  • Sweating
  • Weakness
  • Disorientation and confusion
  • Restlessness
  • Insomnia
  • Anxiety or agitation
  • Urinary retention or frequency
  • Rash or hives
  • Itchy skin
  • Weight gain
  • Change in sexual desire
  • Impotence
  • Breast tissue enlargement or milky discharge
  • Tremor (shakiness)
  • Changes in blood glucose levels
  • Numbness or tingling
  • Sensitivity to light

With the use of any drug, there are also risks of serious side effects. These occur more rarely. When using Silenor, these may include:

  • Orthostatic hypotension (low blood pressure when standing)
  • Hypertension (high blood pressure)
  • Fainting
  • Abnormal heart rhythms
  • Heart attack
  • Stroke
  • Seizures
  • Extrapyramidal symptoms
  • Tardive dyskinesia
  • Hypomania/mania
  • Difficulty walking
  • Increased eye pressure
  • Bowel obstruction
  • Abnormal blood counts
  • Hallucinations
  • Psychosis exacerbation
  • Worsening depression
  • Suicidal thoughts
  • Hepatitis (liver inflammation)
  • Increased body temperature

Safety Precautions

As noted above, certain people should use Silenor with caution or not at all. In rare instances, the medication may affect your heart rhythm, causing QT prolongation. Therefore, you should get a baseline electrocardiogram (ECG) before starting Silenor to identify any risk and to prevent complications such as fainting or sudden death.

It is important that you are monitored by your healthcare provider as the medication is started or changes in the dose are made. In particular, symptoms of suicidality or unusual changes in behavior should be watched for. The medication should not be stopped abruptly as it will cause withdrawal symptoms. If you experience any difficulties, you should be in close contact with your primary health provider.

6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. U.S. Food and Drug Administration. Silenor (doxepin hydrochloride).

  2. Rojas-Fernandez CH, Chen Y. Use of ultra-low-dose (≤6 mg) doxepin for treatment of insomnia in older people. Can Pharm J. 2014;147(5):281-289. doi:10.1177/1715163514543856

  3. Mayo Clinic. Doxepin (Oral Route).

  4. Katwala J, Kumar AK, Sejpal JJ, Terrence M, Mishra M. Therapeutic rationale for low dose doxepin in insomnia patients. Asian Pac J Trop Dis. 2013;3(4):331-336. doi:10.1016/S2222-1808(13)60080-8

  5. Everitt H, Baldwin DS, Stuart B, et al. Antidepressants for insomnia in adults. Cochrane Database Syst Rev. 2018;2018(5):CD010753. doi:10.1002/14651858.CD010753.pub2

  6. Xiong GL, Pinkhasov A, Mangal JP, et al. QTc monitoring in adults with medical and psychiatric comorbidities: Expert consensus from the Association of Medicine and PsychiatryJournal of Psychosomatic Research. 2020;135:110138. doi:10.1016/j.jpsychores.2020.110138

Additional Reading
  • "Doxepin." Epocrates Rx Pro. Version 3.3, 2010. Epocrates, Inc. San Mateo, California.

By Brandon Peters, MD
Brandon Peters, MD, is a board-certified neurologist and sleep medicine specialist.