In the U.S.—

• Antiemetic

Thiethylperazine ( thye-eth-il-PER-a-zeen) is a phenothiazine medicine. It is used to treat nausea and vomiting.

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

Oral
• Tablets (U.S.)

Parenteral
• Injection (U.S.)

Rectal
• Suppositories (U.S.)

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 thiethylperazine, the following should be considered:

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

Pregnancy—Thiethylperazine is not recommended during pregnancy. Other phenothiazine medicines have been reported to cause unwanted effects, such as jaundice and muscle tremors and other movement disorders, in newborn babies whose mothers took these medicines during pregnancy.

Breast-feeding—It is not known if thiethylperazine passes into breast milk. However, thiethylperazine is not recommended for use during breast-feeding because there is the chance that it may cause unwanted effects in nursing babies.

Children—Children are usually more sensitive than adults to the effects of phenothiazine medicines such as thiethylperazine. Certain side effects, such as muscle spasms of the face, neck, and back, tic-like or twitching movements, inability to move the eyes, twisting of the body, or weakness of the arms and legs, are more likely to occur in children, especially those with severe illness or dehydration.

Older adults—Elderly patients are usually more sensitive to the effects of phenothiazine medicines such as thiethylperazine. Confusion; difficult or painful urination; dizziness; drowsiness; feeling faint; or dryness of mouth, nose, or throat may be more likely to occur in elderly patients. Also, nightmares or unusual excitement, nervousness, restlessness, or irritability may be more likely to occur in elderly patients. In addition, uncontrolled movements may be more likely to occur in elderly patients taking thiethylperazine.

Other medicines—Although certain medicines should not be used together at all, in other cases two 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 thiethylperazine, it is especially important that your health care professional know if you are taking any of the following:

• Amoxapine (e.g., Asendin) or
• Antipsychotics (medicine for mental illness) or
• Metoclopramide (e.g., Reglan) or
• Metyrosine (e.g., Demser) or
• Pimozide (e.g., Orap) or
• Promethazine (e.g., Phenergan) or
• Rauwolfia alkaloids (alseroxylon [e.g., Rauwiloid], deserpidine [e.g., Harmonyl], rauwolfia serpentina [e.g., Raudixin], reserpine [e.g., Serpasil]) or
• Trimeprazine (e.g., Temaril)—Side effects of these medicines, such as uncontrolled body movements, may become more severe and frequent if they are used together with thiethylperazine

• Central nervous system (CNS) depressants (medicine that causes drowsiness) or
• Tricyclic antidepressants (medicine for depression)—CNS depressant effects of these medicines or thiethylperazine, such as drowsiness, may be increased in severity; also, taking maprotiline or tricyclic antidepressants may cause some side effects of these medicines, such as dryness of mouth, to become more severe

• Contrast agents, injected into spinal canal—If you are having an x-ray test of the head, spinal canal, or nervous system for which you are going to receive an injection into the spinal canal, thiethylperazine may increase your chance of having seizures

• Epinephrine—Side effects, such as low blood pressure and fast or racing heartbeat, may occur more often or may be more severe

• Levodopa—When used together with thiethylperazine, the levodopa may not work as it should

• Quinidine—Unwanted effects on the heart may occur or become more severe

• Alcohol abuse—This medicine, if taken together with alcohol, may lower the blood pressure and cause CNS depressant effects, such as severe drowsiness

• Asthma attack or
• Other lung diseases—Thiethylperazine may cause secretions to become thick so that it might be difficult to cough them up, for example, during an asthma attack

• Blood disease or
• Heart or blood vessel disease—This medicine may cause more serious conditions to develop

• Difficult urination or
• Enlarged prostate—This medicine may cause urinary problems to get worse

• Glaucoma—This medicine may cause an increase in inner eye pressure

• Liver disease—Thiethylperazine may accumulate in the body, increasing the chance of side effects, such as muscle spasms

• Parkinson's disease or
• Seizure disorders—The chance of thiethylperazine causing seizures or uncontrolled movements is greater when these conditions are present

Thiethylperazine is used only to relieve or prevent nausea and vomiting. Use it only as directed. Do not use more of it and do not use it more often than your doctor ordered. To do so may increase the chance of side effects.

For patients taking this medicine by mouth:

• This medicine may be taken with food or a full glass (8 ounces) of water or milk to reduce stomach irritation.

For patients using the suppository form of this medicine :

• To insert suppository: First, remove foil wrapper and moisten the suppository with cold water. Lie down on your side and use your finger to push the suppository well up into the rectum. If the suppository is too soft to insert, chill it in the refrigerator for 30 minutes or run cold water over it before removing the foil wrapper.
• Wash your hands with soap and water.

Dosing—

The dose of thiethylperazine 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 thiethylperazine. If your dose is different, do not change it unless your doctor tells you to do so.

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 thiethylperazine.

• For nausea and vomiting:
  • For oral dosage form (tablets):
    • Adults—10 milligrams (mg) one to three times a day.
    • Children—Use and dose must be determined by your doctor.
  • For injection dosage form:
    • Adults—10 mg one to three times a day, injected into a muscle.
    • Children—Use and dose must be determined by your doctor.
  • For rectal dosage form (suppositories):
    • Adults—10 mg one to three times a day.
    • Children—Use and dose must be determined by your doctor.

Missed dose—

If you are taking this medicine regularly and you miss a dose, take it as soon as possible. However, if it is almost time for your next dose, 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, since overdose may be very dangerous in children.
• Store away from heat and direct light.
• Do not store the tablet form of this medicine in the bathroom medicine cabinet, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
• 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 are going to be taking this medicine for a long time, your doctor should check your progress at regular visits, especially during the first few months of treatment with this medicine. This will allow your dosage to be changed if necessary to meet your needs.

Thiethylperazine will add to the effects of alcohol and other CNS depressants (medicines that cause you to feel drowsy or less alert). 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 .

This medicine may cause some people to have blurred vision or to become dizzy, lightheaded, drowsy, or less alert than they are normally. 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 dizzy or are not alert or able to see well.

Dizziness, lightheadedness, or fainting may occur, especially when you get up from a lying or sitting position. Getting up slowly may help. If the problem continues or gets worse, check with your doctor.

When using thiethylperazine on a regular basis, make sure your doctor knows if you are taking large amounts of aspirin or other salicylates at the same time (as for arthritis or rheumatism). Effects of too much aspirin, such as ringing in the ears, may be covered up by this medicine.

Thiethylperazine may cause dryness of the mouth, nose, and throat. For temporary relief of mouth dryness, use sugarless candy or gum, melt bits of ice in your mouth, or use a saliva substitute. However, if your mouth continues to feel dry for more than 2 weeks, check with your medical doctor or dentist. Continuing dryness of the mouth may increase the chance of dental disease, including tooth decay, gum disease, and fungus infections.

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:

• Less common or rare
  • Abdominal or stomach pains;  aching muscles and joints;  blurred vision, change in color vision, or difficulty in seeing at night;  confusion (especially in the elderly);  convulsions (seizures);  difficulty in speaking or swallowing;  fast heartbeat;  fever and chills;  inability to move eyes;  lip smacking or puckering ;  loss of balance control;  mask-like face;  muscle spasms (especially of face, neck, and back);  nausea, vomiting, or diarrhea;  nightmares (continuing);  nosebleeds ;  puffing of cheeks;  rapid or fine, worm-like movements of tongue;  shuffling walk;  skin itching (severe);  sore throat and fever;  stiffness of arms or legs ;  swelling of arms, hands, and face;  tic-like or twitching movements;  trembling and shaking of hands and fingers;  twisting movements of body;  uncontrolled chewing movements;  uncontrolled movements of arms or legs;  unusual bleeding or bruising;  unusual excitement, nervousness, restlessness, or irritability;  unusual tiredness or weakness;  weakness of arms and legs ;  yellow eyes or skin 
  
  

• Symptoms of overdose
  • Confusion (severe);  convulsions (seizures) ;  dizziness (severe);  drowsiness (severe);  dry mouth (severe);  hyperextension of neck and trunk;  inability to move eyes;  loss of consciousness;  spasms of face and neck;  stuffy nose;  troubled breathing 
  
  

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
  • Dizziness;  drowsiness 
  
  

• Less common or rare
  • Constipation;  dizziness or lightheadedness, especially when getting up from a lying or sitting position;  dryness of mouth, nose and throat;  fainting;  fever;  headache ;  ringing or buzzing in ears;  skin rash 
  
  

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