Generic name: chloral hydrate [ KLOR-al-HY-drayt ]
Brand name: Somnote
Drug class: Miscellaneous anxiolytics, sedatives and hypnotics

What is chloral hydrate?

Chloral hydrate is a sedative, also called a hypnotic. Chloral hydrate slows the activity of your central nervous system. This medicine has both fast-acting and long-lasting sedative effects.

Chloral hydrate is for short-term use as a sedative or sleep medicine. It is sometimes given before a surgery to help you relax.

Chloral hydrate may also be used to treat alcohol withdrawal symptoms, or to relieve anxiety caused by withdrawal from certain drugs such as barbiturates or narcotic medicine.

Chloral hydrate may also be used for purposes not listed in this medication guide.

What is the most important information I should know about chloral hydrate?

You should not use chloral hydrate if you have severe kidney or liver disease.

What should I discuss with my health care provider before taking chloral hydrate?

You should not use chloral hydrate if you are allergic to it, or if you have:

• severe kidney disease; or

• severe liver disease.

To make sure chloral hydrate is safe for you, tell your doctor if you have:

• a history of liver or kidney disease;

• stomach ulcer, or problems with your esophagus;

• a stomach disorder such as gastroesophageal reflux disease (GERD);

• heart disease;

• porphyria (a genetic enzyme disorder that causes symptoms affecting the skin or nervous system);

• depression, or a history of suicidal thoughts or actions;

• history of drug addiction; or

• if you take furosemide (Lasix), or a blood thinner (warfarin, Coumadin, Jantoven).

FDA pregnancy category C. It is not known whether chloral hydrate will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medicine.

Chloral hydrate can pass into breast milk and may harm a nursing baby. You should not breast-feed while using this medicine.

Do not give this medication to anyone under 18 years old without medical advice.

Older adults may be more sensitive to the effects of this medication.

How should I take chloral hydrate?

Follow all directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results. Do not take this medicine in larger or smaller amounts or for longer than recommended.

Chloral hydrate may be habit-forming. Never share chloral hydrate with another person, especially someone with a history of drug abuse or addiction. Keep the medication in a place where others cannot get to it.

Measure liquid medicine with the dosing syringe provided, or with a special dose-measuring spoon or medicine cup. If you do not have a dose-measuring device, ask your pharmacist for one.

Take this medicine with a full glass of water.

To treat insomnia, take the medicine 15 to 30 minutes before your normal bedtime. Chloral hydrate should be given only for a short time. This medicine may become less effective after 1 or 2 weeks of use.

To use as a sedative, chloral hydrate is usually taken 3 times per day after meals.

To treat alcohol or drug withdrawal, chloral hydrate is usually taken every 6 hours.

Follow your doctor's dosing instructions very carefully.

This medication can cause unusual results with certain medical tests. Tell any doctor who treats you that you are using chloral hydrate.

Call your doctor if your symptoms do not improve, or if they get worse while using chloral hydrate.

Do not stop using chloral hydrate suddenly after long-term use, or you could have unpleasant withdrawal symptoms. Ask your doctor how to avoid withdrawal symptoms when you stop using chloral hydrate.

Store at room temperature away from moisture, heat, and light. Do not freeze. Keep the bottle tightly closed when not in use.

Keep track of the amount of medicine used from each new bottle. Chloral hydrate is a drug of abuse and you should be aware if anyone is using your medicine improperly or without a prescription.

What happens if I miss a dose?

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

If using as a sleep aid: Since chloral hydrate is usually taken as needed for sleep, you may not be on a dosing schedule. Take the medicine only at your normal bedtime.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An overdose of chloral hydrate can be fatal.

Overdose symptoms may include weak or shallow breathing, irregular heart rate, feeling cold, vomiting, choking or chest pressure, dark urine, coughing up blood, muscle weakness or limp feeling, pinpoint pupils, feeling light-headed, or fainting.

What should I avoid while taking chloral hydrate?

Do not drink alcohol. Dangerous side effects or death can occur when alcohol is combined with chloral hydrate.

This medicine may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

Chloral hydrate side effects

Some people using this medicine have engaged in activity such as driving, eating, or making phone calls and later having no memory of the activity. If this happens to you, stop taking chloral hydrate and talk with your doctor about another treatment for your sleep disorder.

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

• severe skin rash;

• signs of a kidney problem--painful or difficult urination; swelling in your feet or ankles; feeling tired or short of breath; or

• increased blood pressure--severe headache, blurred vision, buzzing in your ears, anxiety.

Common side effects may include:

• nausea, vomiting;

• diarrhea; or

• "hangover" feeling.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Related/similar drugs

Chloral hydrate dosing information

Usual Adult Dose for Insomnia:

500 mg to 1 g 15 to 30 minutes before bedtime.

Usual Adult Dose for Sedation:

250 mg 3 times daily after meals, or

500 mg to 1 g 30 minutes before surgery

Usual Pediatric Dose for Insomnia:

Oral, Rectal:
Hypnotic: 50 mg/kg/dose at bedtime
Maximum dose: 1 g/dose
Total maximum: 1 g/day for infants and 2 g/day for children

Usual Pediatric Dose for Sedation:

Neonatal: Oral, Rectal:
For sedation prior to a procedure: 25 mg/kg. Repeat doses should be used with great caution as drug and metabolites accumulate with repeated use; toxicity has been reported after 3 days in a preterm neonate and after 7 days in a term neonate receiving chloral hydrate 40 to 50 mg/kg every 6 hours.

Infants and Children:
Oral, Rectal:
Sedation, anxiety: 25 to 50 mg/kg/day divided every 6 to 8 hours
Maximum dose: 500 mg/dose
Prior to EEG: 25 to 50 mg/kg/dose 30 to 60 minutes prior to EEG; may repeat in 30 minutes to a total maximum of 100 mg/kg or 1 g total for infants and 2 g total for children.
Sedation, nonpainful procedure: 50 to 75 mg/kg/dose 30 to 60 minutes prior to procedure; may repeat 30 minutes after initial dose if needed.
Maximum dose: 120 mg/kg or 1 g total for infants and 2 g total for children

What other drugs will affect chloral hydrate?

Taking this medicine with other drugs that make you sleepy can worsen this effect. Ask your doctor before taking chloral hydrate with a sleeping pill, narcotic pain medicine, muscle relaxer, or medicine for anxiety, depression, or seizures.

Other drugs may interact with chloral hydrate, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Medical Disclaimer

Copyright 1996-2025 Cerner Multum, Inc. Version: 2.01. Revision Date: 2014-03-10, 2:58:21 PM.