Reviewed on 8/20/2021

Brand Name: Unisom

Generic Name: Doxylamine

Drug Class: Sedative/Hypnotics; Antihistamines, Ethanolamine Derivatives

What Is Doxylamine and How Does It Work?

Doxylamine is an over-the-counter (OTC) medication that is used as a nighttime sleep aid or to treat insomnia, as well as treatment for upper respiratory tract allergies. It helps reduce difficulty in falling asleep.

  • Doxylamine is available under the following different brand names: Unisom.

What Are Dosage of Doxylamine?

Dosage of Doxylamine:


Dosage Considerations – Should be Given as Follows:


Adults and Children over 12 years old:

  • 25 mg orally every evening as needed 30 minutes before bedtime

Not recommended for use in children under 12 years old

Upper Respiratory Tract Allergy


  • 50 mg orally every 4-6 hours



Sleep Disorders: Foods That Help Sleep or Keep You Awake See Slideshow

What Are Side Effects Associated with Using Doxylamine?

Side effects of doxylamine include:

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

What Other Drugs Interact with Doxylamine?

If your doctor has directed you to use this medication, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

  • Doxylamine has no known severe interactions with other drugs.
  • Serious interactions of doxylamine include:
    • fentanyl
    • fentanyl intranasal
    • fentanyl iontophoretic transdermal system
    • fentanyl transdermal
    • fentanyl transmucosal
    • isocarboxazid
    • sodium oxybate
    • tranylcypromine
    • valerian
  • Doxylamine has moderate interactions with at least 162 different drugs.
  • Mild interactions of doxylamine include:

This information does not contain all possible interactions or adverse effects. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions, concerns, or for more information about this medicine.

What Are Warnings and Precautions for Doxylamine?


Do not exceed 2 weeks of use.

This medication contains doxylamine. Do not take Unisom if you are allergic to doxylamine or any ingredients contained in this drug.

Keep out of reach of children. In case of overdose, get medical help or contact a Poison Control Center immediately


  • Hypersensitivity

Effects of Drug Abuse

  • No information available

Short-Term Effects

  • See "What Are Side Effects Associated with Using Doxylamine?"

Long-Term Effects

  • See "What Are Side Effects Associated with Using Doxylamine?"


Pregnancy and Lactation

  • Doxylamine use during pregnancy may be acceptable. Either animal studies show no risk but human studies are not available or animal studies showed minor risk and human studies were done and showed no risk
  • Doxylamine excretion in breast milk is unknown. Consult your physician


What is insomnia? See Answer
Medscape. Doxylamine.
RxList. Unisom Monograph.

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