Millions of people take daily medicines for high blood pressure, type 2 diabetes and heart failure without realising that some can become unsafe during a dehydrating illness. The SADMAN rule is a useful reminder of medicines that may need to be paused temporarily when you are vomiting, have significant diarrhoea or cannot drink normally.
What does SADMAN stand for?
The mnemonic covers several commonly prescribed medicine groups:
- S — sulphonylureas, such as gliclazide
- A — ACE inhibitors, such as ramipril or lisinopril
- D — diuretics, such as furosemide
- M — metformin
- A — angiotensin receptor blockers, such as losartan or candesartan
- N — non-steroidal anti-inflammatory drugs, including ibuprofen, naproxen and diclofenac
- Some guidance also includes SGLT2 inhibitors, such as dapagliflozin or empagliflozin.
Why illness changes the risk
Vomiting, diarrhoea, fever and poor fluid intake can reduce circulating fluid volume and blood flow to the kidneys. Some medicines can then accumulate, worsen kidney function or contribute to acute kidney injury. These remain valuable medicines when taken appropriately; the issue is that the balance of benefit and risk can change temporarily during illness.
When should you seek advice?
Sick-day guidance often advises pausing relevant medicines when you cannot maintain normal fluid intake and restarting after you have been eating and drinking normally again. This is not appropriate in every situation. Heart failure, diabetes and other conditions may require individual advice, so contact a healthcare professional if you are uncertain or significantly unwell.
Ibuprofen deserves particular caution because it is available without prescription and can worsen kidney function during dehydration. Ask a pharmacist or doctor which pain relief is appropriate for you.