Chloral Hydrate

Reviewed on 1/13/2022

What Is Chloral Hydrate and How Does It Work?

Chloral Hydrate is a prescription medication used to treat Insomnia, Anxiety and as a Sedative

  • Chloral Hydrate is available under the following different brand name: Somnote

What Are Dosages of Chloral Hydrate?

Adult dosage

Capsule: Schedule IV

  • 500mg

Syrup: Schedule IV

  • 500mg/5mL


Adult dosage

  • 500 mg to 1 gram orally 15-30 minutes before bedtime; for short-term use only (i.e., up to 2 weeks); not to exceed 2 g/24 hours


Adult dosage

  • 250 mg orally after meals every 8 hours; not to exceed 2 g/day

Dosage Considerations – Should be Given as Follows: 

  • See "Dosages."

What Are Side Effects Associated with Using Chloral Hydrate?

Common side effects of Chloral Hydrate include:

  • drowsiness, 
  • trouble waking up, 
  • nausea, 
  • vomiting, 
  • stomach pain, 
  • diarrhea, and
  • headache

Serious side effects of Chloral Hydrate include:

  • slow or shallow breathing, 
  • mood changes, 
  • confusion, 
  • thoughts about others harming, 
  • sleepwalking
  • staggering walk, 
  • loss of balance, 
  • severe dizziness, 
  • fainting
  • vomit that looks like coffee grounds, 
  • difficult or painful swallowing, 
  • black or tarry stools, 
  • severe stomach pain, 
  • changes in the amount of urine, 
  • rash, 
  • itching, 
  • swelling of the face, tongue, or throat, and
  • trouble breathing

Rare side effects of Chloral Hydrate include:


This is not a complete list of side effects and other serious side effects or health problems may occur as a result of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.


Anxiety Disorder Pictures: Symptoms, Panic Attacks, and More with Pictures See Slideshow

What Other Drugs Interact with Chloral Hydrate?

If your medical doctor is using this medicine to treat your pain, 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.

  • Chloral Hydrate has severe interactions with the following drugs:
    • calcium/magnesium/potassium/sodium oxybates
    • sodium oxybate
  • Chloral Hydrate has serious interactions with at least 13 other drugs. 
  • Chloral Hydrate has moderate interactions with at least 187 other drugs.
  • Chloral Hydrate has minor interactions with the following drugs:

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this drug, tell your doctor or pharmacist of all the drugs you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist. Check with your physician if you have health questions or concerns.

What Are Warnings And Precautions for Chloral Hydrate?


  • Hypersensitivity/idiosyncrasy to chloral derivatives
  • Marked renal, hepatic impairment; severe cardiac disease; gastritis and ulcers

Effects of drug abuse

  • None

Short-Term Effects

  • See “What Are Side Effects Associated with Using Chloral Hydrate?”

Long-Term Effects

  • See “What Are Side Effects Associated with Using Chloral Hydrate?”


  • Potential toxic dose children younger than 6 years old: 50 mg/kg
  • Use with caution in porphyria
  • Use caution in long term care patients, elderly, and neonates
  • Use not recommended for above 2 weeks
  • Abrupt discontinuation may cause withdrawal symptoms

Pregnancy and Lactation

  • Use with caution if benefits outweigh risks during pregnancy. 
  • Lactation: small amount secreted into breast milk.
Medscape. Chloral Hydrate.

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