What is Phenergan (Promethazine HCL) used for?

Phenergan (Promethazine) contains the active ingredient promethazine, which is a type of medicine called a sedating antihistamine. It works by preventing the actions of histamine. Histamine is a substance produced by the body as part of its defence mechanisms. It causes the symptoms of allergic reactions. These can include inflammation of the airways or skin, nasal congestion, narrowing of the airways, rashes, and itching of the skin, eyes or nose. Promethazine blocks histamine from binding to its receptors in various parts of the body and this stops it causing the symptoms of an allergic reaction.

Phenergan (Promethazine) also blocks histamine receptors in an area of the brain called the vomiting centre. The vomiting centre is responsible for causing feelings of sickness and for the vomiting reflex. It is activated when it receives nerve messages from the vestibular apparatus in the middle ear. Phenergan is known as a sedating antihistamine because it enters the brain in significant quantities and causes drowsiness. This effect of the medicine is used to produce sedation before minor procedures or surgery, and can also be used to provide short-term help for people with sleeping difficulties (insomnia).

How should I use Phenergan (Promethazine HCL)?

Take Phenergan (Promethazine) by mouth with or without food, usually 4 times daily as needed or as directed by your physician. For motion sickness, Phenergan should be taken 30-60 minutes before beginning travel. If needed, the dose may be repeated 8-12 hours later as directed. For continued travel, your physician may direct you to take Phenergan twice a day, in the morning and before the dinner. For allergies, this medication may be taken at bedtime to decrease daytime drowsiness. When used before surgery, Phenergan may be taken the night before or just before the procedure and may be continued afterwards.

Dosage is based on your age, medical condition, and response to therapy. Take this medication exactly as directed to get the most benefit from it. Do not take more medication or take it more often than prescribed. Ask your physician or pharmacist if you have questions.

What are the side effects of Phenergan (Promethazine HCL)?

• drowsiness
• dizziness
• restlessness
• headache
• nightmares
• tiredness
• blurred vision
• urinary retention
• dry mouth
• confusion
• rash or itching
• loss of appetite
• awareness of your heartbeat
• low blood pressure
• blood disorders
• photosensitivity

Please Note

It is important to tell your physician or pharmacist what medicines you are already taking, including those bought without a prescription, before you start taking Phenergan (Promethazine).

If you are pregnant you should not take Phenergan (Promethazine) without consulting your physician first. This medicine can be used with caution during pregnancy, but only if the expected benefit to the mother outweighs any potential risks to the developing baby. However, Phenergan (Promethazine) should not be used during the last two weeks of a pregnancy, because if taken during this time it may cause irritability or excitement in the baby after birth. Seek further medical advice from your physician.