What You Need to Know About Promethazine
If you suffer from motion sickness or are scheduled for surgery, your doctor may consider a medication called Promethazine to prevent or treat nausea and vomiting. If your doctor has suggested you receive this drug, there are some important things you need to know.
What is Promethazine? What does it do?
Promethazine is an antihistamine (a drug that blocks histamines, compounds in the body that cause a runny nose, watery eyes and swelling tissues) and is used to relieve symptoms of allergic reactions and with other medications to treat anaphylaxis (sudden, severe allergic reaction). Promethazine is also use to treat symptoms of colds, to relax and sedate patients before and after surgery, to treat motion sickness and as a sedative in some countries and to prevent nausea and vomiting following surgery.1
Does Promethazine work?
A review of 24 clinical trials of Promethazine concluded that “despite its widespread use, little data evaluating the therapeutic efficacy of promethazine is available.” The review noted that at that time, promethazine was not recommended in the treatment of PONV (post-operative nausea and vomiting) with other drugs nor by itself for children. The review noted that when compared to placebo, the risk for PONV is decreased by promethazine. However, when compared to no treatment, there was no evidence that Promethazine changed the risk of PONV. 2
In treating motion sickness, a NASA study reported that pre-flight intramuscular treatment (an injection into muscle tissue) with Promethazine cut motion sickness on flight days in half compared to placebo and that 90% of crew members given Promethazine after they felt ill reported relief.3
What should I go over with my doctor before I decide to take Promethazine?
Promethazine has many side effects. Patients treated with Promethazine have reported adverse effects which have included abdominal or stomach pains, black and tarry stool, bleeding gums, blood in urine, bloody nose, blurred vision, chest pain, chills, confusion, cough, dark urine, decreased awareness or responsiveness, difficulty or trouble breathing, double vision, pounding or irregular heart beat, fever, nightmares, tremors, uncontrollable twisting movements of the neck, jaundice, unusual bleeding or bruising and hallucinations.4
Rare side effects of Promethazine can include seizures, difficult or unusually fast breathing, fast heartbeat or irregular pulse, high fever, high or low (irregular) blood pressure, increased sweating, loss of bladder control, severe muscle stiffness, unusually pale skin and unusual tiredness or weakness. 5
In 2009, the FDA issued a boxed warning regarding the injectable form of Promethazine, concerning the possibility of severe tissue damage, including gangrene, in the area of the injection and that the drug can leach out of the vein into the surrounding tissue and do serious damage during administration. The preferred route of injection was recommended into deep muscle tissue and away from an artery.6
What if I’m already taking Promethazine?
If you’re concerned about a medication you’re taking that includes Promethazine or if you experience any adverse effects, talk to your doctor. Never stop taking any prescription medication without talking to your doctor.
It is possible to overdose on Promethazine. If you think you or someone in your household may have taken too much of this medication and experience any of the following, contact emergency services immediately: rapid heartbeat, convulsions, coma, delirium, depression, drowsiness, disorientation, excitation, fever, hallucinations, nervousness, unsteadiness, tremor, flushed skin, dilated pupils with trouble seeing and muscle stiffness in face or neck.7
Learn everything you can about Promethazine before you start taking it.
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1 PubMed Health, “Promethazine”, (Revised 1 January 2011, retrieved 20 October 2012) http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0000637/
2 Signa Vitae, Markic J and Ridge A, “Promethazine in the treatment of postoperative nausea and vomiting: a systematic review” (2011), http://www.signavitae.com/articles/review-articles/171-promethazine-in-the-treatment-of-postoperative-nausea-and-vomiting-a-systematic-review
3 PubMed, Davis JR et al., “Treatment efficacy of intramuscular promethazine for space motion sickness” (March 1993), http://www.ncbi.nlm.nih.gov/pubmed/8447805
4 Mayo Clinic (updated 1 July 2012) http://www.mayoclinic.com/health/drug-information/DR602347/DSECTION=side-effects
5 Mayo Clinic (updated 1 July 2012) http://www.mayoclinic.com/health/drug-information/DR602347/DSECTION=side-effects
6 Food and Drug Administration, “FDA Requires Boxed Warning for Promethazine Hydrochloride Injection” (16 September 2009) http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm182498.htm
7 MedlinePlus, “Promethazine overdose,” (updated 2 February 2011), http://www.nlm.nih.gov/medlineplus/ency/article/002527.htm