If you are checking whether promethazine (Phenergan) can be taken with another medicine, there are a few important things to know. NHS guidance says that promethazine can be taken with some common painkillers, including paracetamol and ibuprofen. However, some medicines can increase drowsiness or other side effects when taken with promethazine.
Medicines that need extra checking include antidepressants, opioid painkillers, medicines that cause drowsiness, some medicines for heart rhythm problems, certain antibiotics and medicines used for epilepsy or seizures. Alcohol should also be avoided while taking promethazine because it can increase its sedating effects.
This guide is written for adults in the UK and covers some of the combinations people commonly ask about. It is not a complete list of every possible interaction, so always tell your pharmacist or doctor about all the medicines, supplements and herbal remedies you take.
Key things to know
- Paracetamol and plain ibuprofen can be taken with promethazine, according to NHS guidance, when used appropriately
- Medicines that cause drowsiness, including some antidepressants, sleeping medicines and opioid painkillers, can increase sleepiness when taken with promethazine
- NHS guidance advises checking with a pharmacist or doctor before taking promethazine with any antidepressant
- Promethazine should be avoided during treatment with MAOI antidepressants and for 14 days after stopping one
Can You Take Ibuprofen with Promethazine?
Yes. NHS guidance says that promethazine can be taken with painkillers such as paracetamol and ibuprofen. There is no specific warning against taking plain ibuprofen with promethazine.
However, ibuprofen has its own precautions. It can cause stomach irritation and may not be suitable for some people with stomach ulcers, kidney problems, certain heart conditions or other health issues. Drinking a lot of alcohol while taking ibuprofen can also increase the risk of side effects.
It is also important to check whether you are taking plain ibuprofen or a combination product. Some products contain ibuprofen alongside another medicine, such as a sedating antihistamine. If the product contains another antihistamine or medicine that causes drowsiness, the advice can be different.
Always check the full ingredients list rather than relying only on the product name. Do not take more than the recommended dose of either medicine.
Can You Take Paracetamol with Promethazine?
Yes. NHS guidance says that promethazine can be taken with paracetamol.
The main thing to watch for is accidentally taking paracetamol from more than one product. Promethazine is sometimes included in combination medicines that also contain paracetamol, particularly some cough and cold products. Taking two products containing paracetamol can result in taking too much, which can cause serious liver damage.
If you are unsure whether another medicine contains paracetamol, check the packaging or ask a pharmacist before taking it.
Promethazine and Antidepressants
NHS guidance recommends checking with a pharmacist or doctor before taking promethazine with any antidepressant. This includes monoamine oxidase inhibitors (MAOIs) as well as other types of antidepressants.
The reason is that antidepressants are a broad group of medicines and they do not all have the same effects or interactions. Some can cause drowsiness, while others can affect heart rhythm or interact with other medicines.
Because of this, it is better to check the exact antidepressant you take rather than assuming that every antidepressant has the same level of risk.
Promethazine and Fluoxetine or Sertraline
Fluoxetine and sertraline are both antidepressants in the SSRI group. NHS guidance advises checking with a pharmacist or doctor before taking promethazine with any antidepressant.
Do not assume that the combination is suitable simply because you have taken either medicine separately before. Your pharmacist can check the exact medicines, doses and any other medicines you take.
If you develop severe or unusual symptoms after taking medicines together, seek medical advice promptly.
Promethazine and Mirtazapine
Mirtazapine is an antidepressant, so the same general advice applies. Check with a pharmacist or doctor before taking it with promethazine.
Mirtazapine can also make some people sleepy. Promethazine is a sedating antihistamine, so taking two medicines that can cause drowsiness may make you more sleepy or less alert.
If you are prescribed both medicines, follow the instructions from your prescriber and let them know about all the medicines you are taking.
Promethazine and Diazepam
Diazepam is a medicine that can cause drowsiness. The NHS advises checking with a pharmacist or doctor before taking promethazine with medicines that make you drowsy.
The Phenergan product information also warns that promethazine can increase the effects of sedative medicines. Taking the two together may therefore increase sleepiness, dizziness and reduced alertness.
If you have been prescribed both medicines, do not change or stop either one without medical advice. Your prescriber can decide whether the combination is appropriate for you and how it should be taken.
Avoid driving, cycling or using machinery if the combination makes you sleepy or affects your concentration.
Promethazine and Tramadol
Tramadol is an opioid painkiller. NHS guidance advises checking with a pharmacist or doctor before taking promethazine with opioid painkillers because they can increase drowsiness and other side effects.
The Phenergan product information also advises caution with medicines that cause sedation.
Because tramadol can cause drowsiness and dizziness itself, adding another sedating medicine may make these effects stronger. If you are taking tramadol and are considering promethazine, speak to your pharmacist or prescriber first.
Do not add extra doses of either medicine because you feel that the first dose has not worked.
Promethazine and Propranolol
Propranolol is not specifically listed on the NHS promethazine interaction page. However, that does not mean that every person can automatically take the two together without checking.
Tell your pharmacist or doctor about propranolol and any other medicines you take. They can consider your medical history, the reason you take propranolol and the other medicines involved before advising you.
This is an important difference between "no specific interaction listed" and "confirmed suitable for everyone". The first does not automatically mean the second.
Can You Take Tums (Antacids) with Promethazine?
This needs a little more care than simply saying yes or no. The UK Phenergan product information says that some gastrointestinal medicines containing magnesium, aluminium or calcium can reduce the absorption of phenothiazines. It advises taking these products separately, with at least 2 hours between them where possible.
Tums is a US antacid brand, and the exact ingredients can vary between products. If you are using an antacid, check its ingredients and ask a pharmacist how far apart to take it from promethazine.
Do not assume that every antacid has exactly the same interaction.
The General Categories Worth Checking: Including Tricyclic Antidepressants
NHS guidance recommends checking with a pharmacist or doctor if you take any of the following with promethazine:
- Any antidepressant, including monoamine oxidase inhibitors (MAOIs)
- Medicines used for an irregular heartbeat, such as amiodarone
- Medicines used to treat epilepsy or seizures
- Certain antibiotics, such as erythromycin
- Opioid painkillers, such as codeine, morphine or oxycodone
- Medicines that cause drowsiness, dry mouth or difficulty passing urine
This is not a complete list. The medicines that can interact with promethazine depend on the exact product and dose, so check the patient information leaflet supplied with your medicine.
Many of these warnings relate to side effects becoming stronger when medicines are taken together. For example, two medicines that cause drowsiness can make you more sleepy, while medicines with similar effects on the heart or bladder may also need extra caution.
A Note on MAOIs Specifically
Monoamine oxidase inhibitors (MAOIs), such as phenelzine, need particular attention.
The UK Phenergan product information says that promethazine should be avoided while taking an MAOI and for 14 days after stopping one.
If you take an MAOI or have stopped one within the last 14 days, do not start promethazine without speaking to your doctor or pharmacist.
Do not assume that an antidepressant is an MAOI just because it is used to treat depression. If you are unsure which type of antidepressant you take, check with your pharmacist.
Herbal Remedies and Supplements
There is not enough information to say that most herbal remedies and supplements are safe to take with promethazine. NHS guidance recommends speaking to a pharmacist, particularly if the product can cause sleepiness, dry mouth or difficulty passing urine.
Herbal products, vitamins and supplements can still affect medicines, even if they are sold as "natural". They are not tested in exactly the same way as prescription and pharmacy medicines, and information about interactions can be limited.
When speaking to a pharmacist, mention everything you take, including occasional supplements and herbal products. This gives them a clearer picture of your medicines.
How to Have This Conversation With a Pharmacist
If you are unsure about a particular combination, take a complete list of your medicines to the pharmacist. Include:
- Prescription medicines
- Pharmacy medicines
- Painkillers
- Cough and cold products
- Vitamins and supplements
- Herbal remedies
- Medicines you only take occasionally
It is also useful to mention any medical conditions you have. For example, if you are considering ibuprofen, tell the pharmacist if you have had stomach ulcers or bleeding, kidney problems or other conditions that may affect whether ibuprofen is suitable.
This is usually more useful than checking each medicine separately online because a pharmacist can look at the whole combination rather than one interaction at a time.
If you have questions about your own combination of medicines or existing health conditions, speak to a pharmacist or doctor before ordering or taking Phenergan 25mg tablets or the elixir.
Genuine Pricing
| Product | Price |
|---|---|
| Phenergan 25mg, 56 tablets | £14.99 |
| Phenergan Elixir 5mg/5ml, 100ml | £14.49 |
Sources
- NHS: Taking promethazine with other medicines and herbal supplements (nhs.uk/medicines/promethazine)
- Promethazine hydrochloride Summary of Product Characteristics, MHRA
The NHS guidance and the official UK product information are useful sources for checking interactions because they relate specifically to promethazine and Phenergan products used in the UK.
Medical Disclaimer
This page provides general information about promethazine interactions. It is not a substitute for personalised medical advice, diagnosis or treatment.
This is not a complete list of every possible interaction. Check the patient information leaflet supplied with your medicine and speak to a pharmacist or doctor about your own medicines.
Do not take promethazine while taking an MAOI or within 14 days of stopping one unless a healthcare professional has specifically advised you otherwise.
Do not drink alcohol while taking Phenergan because alcohol can increase its sedating effects.
Promethazine should not be given to children under 2 years of age. If a medicine makes you sleepy or dizzy, do not drive, cycle or operate machinery.
If you are unsure whether promethazine is suitable with another medicine, speak to your pharmacist or GP before taking the combination.
