Is promethazine (Phenergan) safe to use during pregnancy?

From the Guidelines

Promethazine is not the preferred choice for use during pregnancy, especially in the first trimester, due to the availability of safer alternatives for treating nausea and allergies. According to the most recent evidence from 1 and 1, other antiemetics like doxylamine-pyridoxine combinations or metoclopramide are typically preferred as first-line options for severe nausea and vomiting in pregnancy. Promethazine crosses the placenta and may cause sedation in the newborn if used near delivery, and it also has anticholinergic properties that could potentially affect fetal development 1. For allergic conditions during pregnancy, second-generation antihistamines like cetirizine or loratadine are generally considered safer options.

Some key points to consider when evaluating the use of promethazine during pregnancy include:

• The potential for sedation in the newborn if used near delivery
• The anticholinergic properties that could affect fetal development
• The availability of safer alternatives for treating nausea and allergies
• The need for a thorough discussion with a healthcare provider to weigh the potential benefits against the possible risks for the specific situation

It's also important to note that the decision to use promethazine during pregnancy should be based on the severity of symptoms and the availability of safer alternatives, as recommended by 1 and 1. The European Association for the Study of the Liver Clinical Practice Guidelines on the management of liver diseases in pregnancy, as reported in 1, also recommend doxylamine and pyridoxine and phenothiazines as first-line pharmacologic treatment of hyperemesis gravidarum and metoclopramide and ondansetron as second-line therapies.

In terms of the safety of promethazine during pregnancy, 1 notes that promethazine is considered compatible with use during pregnancy, but it is not the preferred choice due to the availability of safer alternatives. Ultimately, any use of promethazine during pregnancy should only occur after a thorough discussion with a healthcare provider who can weigh the potential benefits against the possible risks for the specific situation.

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

The use of promethazine in pregnancy is categorized as Pregnancy Category C.

• There are no adequate and well-controlled studies in pregnant women.
• Promethazine should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
• The decision to use promethazine in pregnancy should be made with caution, considering the potential risks and benefits 2.

From the Research

Safety of Promethazine in Pregnancy

• The safety of promethazine in pregnancy is a concern due to its potential side effects and interactions with other medications 3, 4.
• Studies have shown that promethazine is effective in treating nausea and vomiting in pregnancy, but its use should be carefully considered due to the potential risks 3, 4.
• One study found that promethazine was as effective as metoclopramide in treating severe nausea and vomiting in pregnancy, but another study found no difference between the two medications after 24 hours 3, 4.
• The use of promethazine in pregnancy should be guided by the severity of symptoms and the potential risks and benefits of treatment 3, 4.

Comparison with Other Medications

• Promethazine has been compared to other medications, such as ondansetron and metoclopramide, in the treatment of nausea and vomiting in pregnancy 3, 4.
• Ondansetron has been shown to be more effective than metoclopramide in reducing nausea, but promethazine was found to be as effective as metoclopramide in one study 3, 4.
• The choice of medication should be based on the individual patient's needs and medical history, as well as the potential risks and benefits of each medication 3, 4.

Potential Risks and Side Effects

• Promethazine has been associated with rare but serious side effects, such as limb-threatening adverse effects after extravasation or inadvertent intra-arterial injection 5.
• Patient safety organizations have called for hospitals to remove injectable promethazine from formularies due to these risks, and the U.S. Food and Drug Administration has updated the product labeling to include recommendations for safe administration 5.
• The use of promethazine in pregnancy should be carefully considered due to these potential risks, and alternative medications should be considered when possible 3, 4, 5.