Drug
Promethazine
Pronounced
"pro-METH-uh-zeen"
Uses
Promethazine is used to prevent and treat nausea and vomiting related to certain conditions (such as before/after surgery, motion sickness). It is also used with other medication to treat severe allergic reactions (anaphylaxis) and reactions to blood products. It may also be used to treat milder allergic reactions when you cannot take promethazine by mouth. It may also be used to help you feel sleepy/relaxed before and after surgery, during other procedures, or during labor and delivery. It may also be used to help certain opioid pain relievers (such as meperidine) work better.
Promethazine is an antihistamine and works by blocking a certain natural substance (histamine) that your body makes during an allergic reaction. Its other effects (such as anti-nausea, calming, pain relief) may work by affecting other natural substances (such as acetylcholine) and by acting directly on certain parts of the brain.
This drug is not approved for use in children younger than 2 years due to an increased risk of side effects (such as slow/shallow breathing). See also Warning section.
Warning
Promethazine should not be used by children younger than 2 years because it may cause serious (possibly fatal) slow/shallow breathing. When this medication is used by children 2 years and older, use the lowest effective dosage and avoid other drugs that affect breathing. Get medical help right away if slow/shallow breathing occurs.
In children, drugs for nausea should only be used in cases of prolonged vomiting of a known cause. Avoid use of promethazine in children with liver disease (including possible Reye's syndrome).
This medication can cause severe tissue damage, possibly requiring surgery. Tell your health care professional right away if you have burning, pain, redness, swelling, or numbness at or near the injection site. If this occurs, the injection should be stopped and the injection site checked.
It is preferred that this medication be given by injection into a muscle. There may be an increased risk of side effects if this medication is given by injection into a vein. This medication must not be given by injection under the skin.
How to Use This Medication
See also Warning section.
This medication is given by injection into a muscle or a vein by a health care professional. It should not be injected under the skin or into an artery. For nausea and vomiting, this medication is given as directed by your doctor, usually every 4 hours as needed.
The dosage is based on your age, medical condition, and response to treatment. Children's dosage may also be based on weight.
Tell your doctor if you do not get better or if you get worse.