Promethazine is not contraindicated in pregnancy. It is recommended by the Royal College of Obstetricians and Gynaecologists as a first line option for nausea and vomiting in pregnancy, alongside medicines such as cyclizine, prochlorperazine and chlorpromazine. Current UKTIS information says that the available data do not support an association between promethazine exposure during pregnancy and birth defects.
That is a reassuring answer, but there is an important point to understand. Promethazine can cause significant drowsiness, and its use for pregnancy sickness is outside the licensed indications for some products. There is also a specific caution about high doses during late pregnancy because of possible effects on the newborn. Breastfeeding is a separate question, with its own advice.
Key things to know
- Promethazine is recommended by RCOG as a first line anti sickness medicine for nausea and vomiting in pregnancy.
- UKTIS says the available data do not support an association between promethazine exposure during pregnancy and birth defects.
- High doses during late pregnancy may cause neurological effects in a newborn, so use close to delivery needs particular care.
- Promethazine is not specifically licensed for pregnancy sickness in the UK. Doxylamine with pyridoxine is the only licensed medicine specifically indicated for nausea and vomiting in pregnancy.
- The UK does not use pregnancy letter categories. The FDA replaced its old letter system in 2015.
- While breastfeeding, promethazine can be used occasionally or for a short time if the baby is healthy, but it may make the baby sleepy. A different antihistamine may be preferred for some allergy symptoms.
Is promethazine safe in pregnancy
Is promethazine safe in pregnancy, promethazine safe in pregnancy, promethazine safety in pregnancy and promethazine safety during pregnancy are all asking essentially the same question.
The answer from current UK guidance is reassuring. UKTIS says that the available data overall do not support an association between promethazine exposure during pregnancy and congenital malformations. The data also do not suggest increased risks of miscarriage, stillbirth, preterm delivery or low birth weight, although the amount of evidence available for some of these outcomes is more limited.
RCOG also recommends promethazine as one of the first line options for nausea and vomiting in pregnancy when an anti sickness medicine is needed.
So, is promethazine contraindicated in pregnancy? No. It can be used during pregnancy when a healthcare professional considers it appropriate. It can cause drowsiness, however, and the dose and reason for treatment still matter.
If you are pregnant and considering promethazine, speak to your GP, midwife or pharmacist before taking it. This is particularly important if you are taking other medicines or are close to your due date.
Promethazine and pregnancy sickness
Nausea and vomiting in pregnancy affects up to 90% of pregnant women. It usually starts between weeks four and seven and settles by week 20 in around 90% of cases, although some people continue to have symptoms for longer.
When self care is not enough, UK guidance gives several anti sickness medicines that can be considered.
| Line | Options |
|---|---|
| First line | Cyclizine or promethazine, or prochlorperazine or chlorpromazine |
| Licensed option | Doxylamine with pyridoxine, the only medicine specifically licensed in the UK for nausea and vomiting in pregnancy |
| Later options | Metoclopramide, domperidone or ondansetron may be considered if earlier treatments have not worked |
| Hospital care | May be needed if symptoms cause dehydration, significant weight loss or you cannot keep fluids or oral medicines down |
The exact medicine and dose depend on your symptoms and individual circumstances. There is no need to struggle with severe pregnancy sickness without help.
If you are vomiting frequently, losing weight, becoming dehydrated or cannot keep fluids or medicines down, speak to your GP or maternity team. Severe symptoms may be hyperemesis gravidarum and can require treatment in hospital.
Promethazine in pregnancy by trimester
Promethazine pregnancy first trimester questions are common because this is when pregnancy sickness often starts and when many people are most concerned about taking medicines.
First trimester
Promethazine in pregnancy first trimester use is not prohibited. RCOG includes promethazine among the anti sickness medicines that can be used in pregnancy, including during the first trimester. UKTIS says the available evidence does not support an increased risk of birth defects following promethazine exposure.
Promethazine pregnancy first trimester dosage is not something to work out from a website. Your healthcare professional can decide whether it is appropriate and advise you on the dose based on your symptoms and circumstances.
Second trimester
Is promethazine safe in pregnancy second trimester? There is no specific restriction in the current UKTIS pregnancy information. Many people find pregnancy sickness settles by around week 20, but some continue to have symptoms for longer.
If you still need treatment, your doctor or midwife can review whether you should continue with promethazine or consider another option.
Third trimester
This is the part that deserves particular attention. Is promethazine safe in pregnancy third trimester, promethazine while pregnant 3rd trimester and promethazine third trimester all point to the same issue.
UKTIS says that high doses of promethazine during late pregnancy can cause prolonged neurological effects in the newborn. These can include unusual excitability, restlessness, nightmares and disorientation. If exposure occurs close to delivery, UKTIS says that delivery in a unit with neonatal monitoring facilities should be considered.
This does not mean that promethazine cannot be used late in pregnancy. It means that the dose and timing need careful consideration.
If you are taking promethazine and approaching your due date, tell your midwife, obstetrician or doctor. They can decide whether any changes or additional monitoring are needed.
Promethazine pregnancy category
Promethazine pregnancy category and Phenergan pregnancy category are common searches, but the question does not really apply in the UK.
The UK does not use pregnancy letter categories such as A, B, C, D and X. The FDA replaced its old letter system in 2015 with more detailed descriptions of the available evidence.
Australia has its own pregnancy category system, which is one reason you may see category letters in information online. Those categories should not be treated as UK safety ratings.
For UK advice, it is more useful to look at sources such as the product information, NHS guidance, UKTIS and BUMPS, along with professional guidance from organisations such as RCOG.
So if you have found a category letter for promethazine online, check which country's system it comes from before relying on it.
Promethazine and breastfeeding
Promethazine and breastfeeding, promethazine breastfeeding, Phenergan breastfeeding, Phenergan and breastfeeding, promethazine while breastfeeding, Phenergan while breastfeeding and promethazine in breastfeeding are asking a slightly different question from promethazine in pregnancy.
The NHS says that if your baby is healthy, you can take promethazine while breastfeeding, but it is best to use it occasionally or for a short time and to speak to your doctor or pharmacist first. It is not known exactly how much promethazine passes into breast milk, but the amount is expected to be low.
Promethazine is a drowsy antihistamine, so it may make a breastfed baby sleepy. Watch your baby for unusual sleepiness, difficulty feeding or irritability. If you notice these symptoms, contact your healthcare professional or NHS 111 for advice.
It is also important not to share a bed with your baby while taking promethazine because the medicine can make you drowsy.
For allergy symptoms while breastfeeding, your doctor or pharmacist may suggest a different antihistamine. The NHS specifically notes that non drowsy options such as loratadine may be preferred for hay fever.
If your baby was premature or is unwell, ask your doctor or pharmacist before taking promethazine.
Promethazine BNF, and where the reliable information is
Promethazine BNF searches usually come from people looking for reliable dosing or prescribing information. The British National Formulary is a professional reference used by healthcare professionals, rather than a patient information leaflet.
For pregnancy and breastfeeding, useful UK sources include the patient leaflet supplied with your medicine, the Summary of Product Characteristics, NHS guidance, RCOG guidance and the Best Use of Medicines in Pregnancy information produced by UKTIS.
UKTIS says that current evidence does not suggest increased risks of congenital malformations, miscarriage, stillbirth, preterm delivery or low birth weight following promethazine exposure, although the evidence for some outcomes is limited. It also highlights the specific concern about high doses during late pregnancy and possible effects on the newborn.
If you are pregnant, tell your healthcare professional about any other medicines you take. This helps them check for interactions and decide which treatment is most appropriate for you.
What about Phenergan tablets specifically
Phenergan in pregnancy, Phenergan and pregnancy, Phenergan pregnancy, promethazine hydrochloride in pregnancy and promethazine 25 mg tablet pregnancy questions all concern the same active ingredient. Phenergan is a brand name for medicines containing promethazine hydrochloride, so the pregnancy information about promethazine applies to the active ingredient in Phenergan.
One distinction matters. Phenergan products are used for conditions such as allergies, motion sickness and short term sleep problems. Pregnancy sickness is a separate use, and promethazine is not specifically licensed for that indication in the UK.
Promethazine while pregnant, promethazine when pregnant and promethazine during pregnancy therefore have the same practical answer. If you are considering it for pregnancy sickness, speak to your GP, midwife or pharmacist rather than choosing a dose yourself.
Allergy and sleep in pregnancy, which is a different question
Not everyone searching for promethazine hydrochloride pregnancy information is asking about sickness. Hay fever can still be a problem during pregnancy, and sleep can become difficult too.
For allergy symptoms in pregnancy, your doctor or pharmacist can help you choose an appropriate treatment. The NHS notes that a non drowsy antihistamine such as loratadine may be recommended for hay fever.
For sleep problems, promethazine is licensed for short term insomnia in adults, but it can cause significant drowsiness. The product information advises seeking medical advice if it is needed for more than 7 days. Pregnancy is a good reason to discuss ongoing sleep problems with your healthcare professional rather than relying on promethazine every night.
Either way, asking before you buy is a better approach than trying to work out the right medicine and dose yourself.
What to tell your GP or midwife
- How many weeks pregnant you are, or whether you are breastfeeding and how old your baby is.
- What your symptoms are, how severe they are and whether you are able to keep fluids down.
- Everything else you take, including medicines bought without a prescription and supplements.
- Whether you have epilepsy, asthma, liver or kidney problems, glaucoma or any other condition your doctor should know about.
- Whether you have taken an MAOI medicine within the previous 14 days, as this can interact with promethazine.
- If you are close to your due date, tell your maternity team if you are taking promethazine.
The age restrictions for promethazine depend on the specific formulation and indication, so check the product information or ask a pharmacist rather than applying one age limit to every promethazine product.
Cost and where a pharmacist fits in
Phenergan is available as a pharmacy medicine for some licensed uses, but pregnancy sickness is a different situation and should be discussed with a healthcare professional.
| Product | Pack | Price |
|---|---|---|
| Phenergan 25mg tablets | 56 tablets | £14.99 |
| Phenergan Elixir 5mg/5ml | 100ml oral solution | £14.49 |
Prices were verified on the product pages at the time of writing and the live pages take precedence. The tablets and elixir contain the same active ingredient, but they are different formulations and should be used according to the instructions for the specific product.
If you are pregnant or breastfeeding, tell the pharmacist before buying promethazine. They can check whether it is appropriate for you and whether another option may be better suited.
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