Is Phenergan (Promethazine) safe during pregnancy?

From the Guidelines

Phenergan (promethazine) is considered compatible with pregnancy, including the first trimester, according to the most recent guidelines. The European Association for the Study of the Liver Clinical Practice Guidelines on the management of liver diseases in pregnancy, published in 2023 1, list promethazine as a compatible medication during pregnancy, including the first trimester. Additionally, the American Gastroenterological Association (AGA) clinical practice update on pregnancy-related gastrointestinal and liver disease, published in 2024 1, suggests that promethazine can be used as a second-line treatment for hyperemesis gravidarum. However, it is essential to note that the use of Phenergan during pregnancy should be carefully evaluated, and safer alternatives like vitamin B6, doxylamine, or metoclopramide should be considered first. The concern with Phenergan during pregnancy relates to its antihistamine properties and potential effects on the developing fetus, as well as the risk of respiratory depression in newborns if used near delivery time.

Some key points to consider when using Phenergan during pregnancy include:

• The medication should only be used when the potential benefits clearly outweigh the risks
• Safer alternatives should be tried first
• The use of Phenergan near delivery time should be avoided due to the risk of respiratory depression in newborns
• Healthcare providers should carefully evaluate the use of Phenergan during pregnancy and monitor patients closely for any adverse effects.

It is also worth noting that the evidence on the use of Phenergan during pregnancy is not conclusive, and some studies suggest a possible association with birth defects when used in early pregnancy 1. However, the most recent guidelines suggest that promethazine can be used during pregnancy, including the first trimester, when necessary.

In terms of management of nausea and vomiting during pregnancy, diet and lifestyle modification are the initial steps, and therapeutic options include ginger, vitamin B6, and H1-receptor antagonists like doxylamine and promethazine 1. Early intervention and treatment of nausea and vomiting may help prevent progression to hyperemesis gravidarum.

Ultimately, the decision to use Phenergan during pregnancy should be made on a case-by-case basis, taking into account the individual patient's situation and medical history, and under the guidance of a healthcare provider.

From the FDA Drug Label

Teratogenic effects have not been demonstrated in rat-feeding studies at doses of 6.25 and 12.5 mg/kg of promethazine HCl. There are no adequate and well-controlled studies of promethazine hydrochloride tablets in pregnant women. Promethazine hydrochloride tablets should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus

Phenergan (promethazine) use in pregnancy is not recommended without careful consideration of the potential risks and benefits.

• The drug label indicates that there are no adequate and well-controlled studies in pregnant women.
• Promethazine hydrochloride tablets should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus 2.
• It is essential to weigh the potential benefits against the potential risks to the fetus before using Phenergan in pregnancy.

From the Research

Phenergan Safety in Pregnancy

• Phenergan, also known as promethazine, is an antihistamine that is sometimes used to treat nausea and vomiting in pregnancy 3.
• However, there is limited evidence on the safety of Phenergan in pregnancy, and it is not commonly recommended as a first-line treatment for nausea and vomiting in pregnancy 3.
• A study comparing metoclopramide and promethazine in labor found that both medications were effective in reducing nausea and vomiting, but metoclopramide was associated with better analgesia and less sedation 4.
• Another study found that ondansetron, a different antiemetic medication, was associated with improved symptoms and fewer side effects compared to metoclopramide in women with moderate to severe nausea and vomiting in pregnancy 3.
• The safety of Phenergan in pregnancy has not been extensively studied, and more research is needed to determine its safety and efficacy in this population.

Alternative Treatments

• Other medications, such as metoclopramide, ondansetron, and pyridoxine-doxylamine, have been shown to be effective in treating nausea and vomiting in pregnancy 5, 3, 6.
• Ginger and vitamin B6 have also been found to be beneficial in reducing symptoms of nausea and vomiting in pregnancy 3.
• Corticosteroids may be associated with benefit in severe cases of hyperemesis gravidarum, but more research is needed to confirm this 3.

Risks and Side Effects

• Metoclopramide has been associated with an increased risk of premature birth, but not with an increased risk of major malformations or spontaneous abortions 6.
• Ondansetron has been found to have a favorable side effect profile compared to metoclopramide, with fewer reports of headache, dizziness, and constipation 3.
• The risks and side effects of Phenergan in pregnancy are not well understood and require further study.