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Over the Counter medicines, Natural medicines and Supplements 

As a patient with a renal condition, there may be problems with you buying medicines over the counter to treat minor ailments i.e. from pharmacies, shops or garages. The same applies to buying natural medicines or supplements. The word medicine includes tablets, capsules, liquids or creams that either your doctor gives you or that you buy.

This is relevant whether you have poor renal function, are on dialysis or have a transplant. You may have a number of medical conditions and are therefore prescribed several medicines from your doctor. As a result, some of the medicines or supplements that can be bought over the counter from pharmacies and other shops may be unsuitable for you.

Problems that may happen with medicines or supplements that you can buy:

  • They may cause problems with other medicines you take.
  • Some may make your kidney function worse.
  • Some products contain things that are bad for you, like potassium, sodium or aluminium.

However, if you talk to your doctor or pharmacist, it should still be possible for you to buy suitable medicines to treat minor ailments.

Some points to remember when buying medicines:

  • It is very important to tell any doctor or pharmacist recommending a medicine for you about your renal condition and the medicines you are taking.
  • You should only treat minor ailments by yourself for 2-3 days. If your symptoms change, get worse or last for more than 3 days, see your doctor.
  • Be aware that some of the tablets your doctor gives you can also be bought over the counter. Be careful not to take double the dose.
  • Be careful not to take more than one painkiller with paracetamol in - do not forget that co-codamol and co-proxamol contain paracetamol.
  • Effervescent tablets (tablets that dissolve in water) are best avoided because they contain sodium.
  • Remember to tell the pharmacist if you are diabetic or have had an allergic reaction to any medicine.
  • Try to use the same pharmacy so that the pharmacist can build up a complete picture of all the drugs you are taking. He/she will then be able to provide you with the best advice.
  • If you find that you need to treat the same symptoms frequently, please do not forget to mention them to your doctor at your next visit.
  • When the renal team ask which medications you take, include those you buy yourself.
  • You should remember that, although some medicines are not recommended for you to buy, they may be safe for your doctor to prescribe them.


Over the counter medicines


What to avoid

Safer alternatives



High-dose aspirin*, ibuprofen, all effervescent (dissolve in water) preparation


If your symptoms don’t improve see your doctor

Coughs and colds

Any medicines containing decongestants such as ephedrine, pseudoephedrine, oxymetazoline

High-dose aspirin* or ibuprofen

Paracetamol for aches and pains

Could use simple linctus to soothe coughs- ask for sugar free versions if diabetic

Could try menthol or steam inhalation to clear any congestion

Muscle aches

Ibuprofen, naproxen or diclofenac tablets or creams

Capsaicin cream or Ralgex



Avoid any medicines containing magnesium, aluminium, sodium or potassium unless your doctor has advised it is ok

Medicines containing calcium as long as your calcium levels are not high

See your doctor if you have indigestion regularly


Fybogel if on a fluid restriction

Senna, lactulose, sodium docusate



Rehydration salts unless advised by your doctor


If severe contact your doctor

*This dose not include low-dose aspirin - aspirin 75mg daily which you may be taking for other reasons

High dose Aspirin (doses of greater than 300mg daily), ibuprofen and naproxen belong to a group of medicines called non-steroidal anti-inflammatory drugs (NSAIDs). Diclofenac is one of many NSAIDs available from your doctor. NSAIDs can be very harmful to kidneys, so if you have a transplant or have poor renal function not requiring dialysis all NSAIDs should be avoided. They can also increase your risk of developing a stomach ulcer which may cause bleeding from the stomach, anaemia and also lead to water retention.


Vitamins or supplements

Vitamins and minerals are substances your body needs to help carry out important functions.

Vitamin A

It is advisable to avoid Vitamin A, unless recommended to you, as it can build up in patients with kidney disease. It may be found in a number of multivitamins so please check the label.

Vitamin D

It is advisable that you seek advice from your kidney team prior to taking vitamin D supplements to ensure you receive the right dose and are not already taking other types of vitamin D.

Food and Drink

Many foods and food supplements can affect medicines we give you for your kidney(s). For example, grapefruit, cranberry, ginger, and turmeric, but there are many more. They do this by making the levels of your medicines go up or down. This can affect the medicine working or increase the chances of side effects. The medicines most affected are the ones we do lots of monitoring for.

Before taking any vitamins, supplements or making big changes to your diet please speak to your local pharmacist or kidney team.

This is very important if you are taking following medicines:

  • tacrolimus
  • ciclosporin
  • everolimus
  • sirolimus
  • voclosporin
  • warfarin
  • tolvaptan

Natural medicines

Please seek advice before taking any herbal medicines from your local pharmacist or kidney team. Below are just a few examples of herbal medicines that may have significant impact on kidney patients’ medicines, but there are many more.

St Johns Wort

St Johns Wort has been widely used for a number of years to improve mood. However, it has also been found to have an impact on the levels of many medicines, some examples being tacrolimus, warfarin, as well as medicines used to improve mood and help with anxiety.

CBD oil  

Cannabidiol better known as CBD oil has become increasingly popular in recent years. It can be bought in many shops such as pharmacies or health food shops. It has been shown to reduce the breakdown of some drugs by the body, leading to higher drugs levels. An example of this includes tacrolimus which could be harmful. Side effects such as drowsiness, fatigue and dry mouth can be exacerbated in patients with kidney disease.

Last reviewed July 2023
Next review July 2026

Written by
Kathrine Parker Renal Pharmacist Manchester University NHS Trust &
Cathy Pogson Renal Pharmacist Portsmouth NHS Trust

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The National Kidney Federation cannot accept responsibility for information provided. The above is for guidance only. Patients are advised to seek further information from their own doctor.