In the U.S.—

• Anticonvulsant

Paraldehyde ( par-AL-de-hyde) is used to treat certain convulsive disorders. It also has been used in the treatment of alcoholism and in the treatment of nervous and mental conditions to calm or relax patients who are nervous or tense and to produce sleep. However, this medicine has generally been replaced by safer and more effective medicines for the treatment of alcoholism and in the treatment of nervous and mental conditions.

This medicine is available only with your doctor's prescription, in the following dosage forms:

Oral
• Oral liquid (U.S. and Canada)

Parenteral
• Injection (Canada)

Rectal
• Rectal liquid (U.S. and Canada)

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For paraldehyde, the following should be considered:

Allergies—Tell your doctor if you have ever had any unusual or allergic reaction to paraldehyde. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy—Paraldehyde crosses the placenta. Studies on birth defects have not been done in either humans or animals. Use of paraldehyde during labor may cause breathing problems in the newborn infant.

Breast-feeding—Paraldehyde has not been reported to cause problems in nursing babies.

Children—Although there is no specific information comparing use of paraldehyde in children with use in other age groups, this medicine is not expected to cause different side effects or problems in children than it does in adults.

Older adults—Many medicines have not been studied specifically in older people. Therefore, it may not be known whether they work exactly the same way they do in younger adults or if they cause different side effects or problems in older people. There is no specific information comparing use of paraldehyde in the elderly with use in other age groups.

Other medicines—Although certain medicines should not be used together at all, in other cases 2 different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking paraldehyde, it is especially important that your health care professional know if you are taking any of the following:

• Central nervous system (CNS) depressants (medicine that causes drowsiness) or
• Tricyclic antidepressants (medicine for depression)—CNS depressant effects may be increased

• Disulfiram (e.g., Antabuse)—Higher blood levels of paraldehyde may occur, increasing the chance of side effects

• Alcohol abuse (or history of) or
• Drug abuse or dependence (or history of)—Dependence on paraldehyde may develop

• Colitis—Paraldehyde used rectally may make the condition worse

• Emphysema, asthma, bronchitis, or other chronic lung disease, or
• Liver disease—Higher blood levels of paraldehyde may occur, increasing the chance of side effects

• Gastroenteritis (stomach flu) or
• Stomach ulcer—Paraldehyde taken by mouth may make the condition worse

Use this medicine only as directed by your doctor. Do not use more of it, do not use it more often, and do not use it for a longer time than your doctor ordered. If too much is used, the medicine may become habit-forming.

Do not use if liquid turns brownish in color or if it has a strong vinegar-like odor, since this means the paraldehyde is breaking down. If you have any questions about this, check with your health care professional.

For patients taking this medicine by mouth:

• Do not use a plastic spoon, plastic glass, or any other plastic container to take this medicine, since paraldehyde may react with the plastic. Use a metal spoon or glass container.
• Take this medicine mixed in a glass of milk or iced fruit juice to improve the taste and odor and to lessen stomach upset.

For patients using this medicine rectally:

• Do not use paraldehyde in any plastic container since it may react with the plastic.
• Before using paraldehyde rectally, make sure you understand exactly how to use it. Paraldehyde may need to be diluted. If you have any questions about this, check with your health care professional.

Keep this medicine away from the eyes and avoid getting it on the skin and clothing.

Keep this medicine away from heat, open flame, and sparks.

Dosing—

The dose of paraldehyde will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of paraldehyde. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of paraldehyde that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are taking paraldehyde.

• For oral and rectal dosage forms (liquid):
  • Adults: Dose must be determined by your doctor.
  • Children: Dose is based on body weight, and must be determined by the doctor.
• For injection dosage form:
  • Adults: Dose must be determined by your doctor. It will be injected into a muscle or a vein.
  • Children: Dose is based on body weight, and must be determined by the doctor.

Missed dose—

If you are taking this medicine regularly (for example, every day) and you miss a dose, take it right away if you remember within an hour or so of the missed dose. However, if you do not remember until later, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage—

To store this medicine

• Keep out of the reach of children.
• Store away from heat and direct light.
• Keep the medicine from freezing.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.

If you will be using this medicine regularly for a long time:

• Your doctor should check your progress at regular visits.
• Do not stop using it without first checking with your doctor. Your doctor may want you to reduce gradually the amount you are using before stopping completely.

This medicine will add to the effects of alcohol and other CNS depressants (medicines that slow down the nervous system, possibly causing drowsiness). Some examples of CNS depressants are antihistamines or medicine for hay fever, other allergies, or colds; sedatives, tranquilizers, or sleeping medicine; prescription pain medicine or narcotics; barbiturates; medicine for seizures; muscle relaxants; or anesthetics, including some dental anesthetics. Check with your doctor before taking any of the above while you are using this medicine.

Before you have any medical tests, tell the medical doctor in charge that you are taking this medicine. The results of some tests, such as the metyrapone test and the phentolamine test, may be affected by this medicine.

If you think you or someone else may have taken an overdose of this medicine, get emergency help at once. Taking an overdose of paraldehyde or taking alcohol or other CNS depressants with paraldehyde may lead to unconsciousness and possibly death. Some signs of an overdose are confusion, muscle tremors, nausea or vomiting (continuing or severe), severe stomach cramps, severe weakness, shortness of breath or slow or troubled breathing, and slow heartbeat.

This medicine may cause some people to become drowsy or less alert than they are normally. Even if taken at bedtime, it may cause some people to feel drowsy or less alert on arising. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are not alert.

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor as soon as possible if any of the following side effects occur:

• More common
  • Coughing (with injection only);  skin rash 
  
  

• Less common
  • Redness, swelling, or pain at injection site 
  
  

• With long-term use
  • Yellow eyes or skin 
  
  

• Symptoms of overdose
  • Cloudy urine;  confusion;  decreased urination;  fast and deep breathing ;  muscle tremors;  nausea or vomiting (continuing or severe);  nervousness, restlessness, or irritability;  shortness of breath or slow or troubled breathing;  slow heartbeat;  stomach cramps (severe);  weakness (severe)  
  
  

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

• More common
  • Drowsiness;  nausea or vomiting (when taken by mouth);  stomach pain (when taken by mouth) ;  unpleasant breath odor 
  
  

• Less common
  • Clumsiness or unsteadiness;  dizziness ;  ``hangover'' effect 
  
  

After you stop using this medicine, your body may need time to adjust. The length of time this takes depends on the amount of medicine you were using and how long you used it. During this period of time check with your doctor if you notice any of the following side effects:

• Convulsions (seizures);  hallucinations (seeing, hearing, or feeling things that are not there);  increased sweating;  muscle cramps;  nausea and vomiting;  stomach cramps;  trembling 

Paraldehyde will cause your breath to have a strong unpleasant odor. This effect will last until about one day after you have stopped using this medicine.

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.