Sick Day Rules: Important Advice for Patients on Certain Long-Term Medicines
Some long-term medicines can be harmful if taken during illness—particularly when you’re at risk of dehydration or have a significant infection. This page explains when you should pause certain medications and seek medical advice to stay safe.
Which Medicines Are Affected?
If you take any of the medicines below, you may need to temporarily stop them if you become unwell. Your doctor, nurse or pharmacist may highlight which apply to you:
- ACE Inhibitors (e.g. lisinopril, ramipril) – used for high blood pressure and heart conditions
- ARBs (e.g. losartan, candesartan) – used for high blood pressure and heart conditions
- NSAIDs (e.g. ibuprofen, naproxen, diclofenac) – anti-inflammatory painkillers
- Diuretics (e.g. furosemide, bendroflumethiazide) – “water tablets” for fluid retention or high blood pressure
- Metformin – for type 2 diabetes
- SGLT2 Inhibitors (e.g. dapagliflozin, empagliflozin) – for type 2 diabetes
- DMARDs (Disease-Modifying Anti-Rheumatic Drugs)
Includes methotrexate, sulfasalazine, leflunomide, hydroxychloroquine, azathioprine, mycophenolate, and biologics such as adalimumab or etanercept
What Kind of Illness Requires Action?
You should take action if you experience an illness that increases your risk of dehydration or infection, such as:
- Vomiting or diarrhoea, especially if you have more than one episode
- Fever, with or without sweats or shivering
- Flu-like symptoms or signs of a chest or urine infection
- Any infection that leads to you being prescribed antibiotics
These illnesses reduce your body’s ability to safely process certain medicines, and continuing them may increase the risk of serious complications such as kidney injury or infection.
What Should You Do?
If you’re unwell with vomiting, diarrhoea, or fever:
- Temporarily stop the medicines listed above
- Do not take extra doses when you restart—just resume your normal routine
- Restart them only once you are eating and drinking normally for 24 to 48 hours
- If unsure, speak to your pharmacist, GP, or nurse
Special Advice for Patients on DMARDs
DMARDs are medicines that reduce inflammation by dampening the immune system. They are commonly used for conditions like rheumatoid arthritis, lupus, or inflammatory bowel disease.
If you’re taking a DMARD (including biologics), you must stop your DMARD and seek advice if:
- You have a fever, flu-like symptoms, or feel generally unwell
- You have signs of a chest infection, urine infection, or another bacterial illness
- You are prescribed antibiotics for any infection
- You are unsure whether your symptoms may be due to an infection
Continuing DMARDs during infection can impair your body’s ability to fight illness and increase the risk of serious complications, including sepsis.
Only restart your DMARD when:
- You have fully recovered
- Any prescribed antibiotics are completed
- A healthcare professional has confirmed it is safe to restart
If your medication requires regular blood monitoring, ensure this is up to date after any illness.
Need Help or Advice?
If you’re not sure which medicines to stop or when to restart them:
- Speak to your pharmacist for quick advice
- Contact your GP or practice nurse if you’re concerned or symptoms persist
- In an emergency, call 111 or attend your nearest urgent care service
Keeping you safe during illness is our priority. If you’re unsure, always ask. We’re here to help.