Need to know
The current heatwave could have a negative effect on certain medicines
17:06, 27 May 2026Updated 17:11, 27 May 2026
Need to know: heatwave warning as common medications may be affected by high temperatures
- A pharmacy expert has warned millions of people that the UK’s current heatwave could dangerously affect common medications.
- Rhysa Phommachanh, health specialist at Landys Chemist, said critical drugs including insulin and EpiPens are among those at risk. She explained: “Insulin can become less effective if it is exposed to high temperatures, as heat can cause it to degrade and reduce its ability to properly control blood sugar levels.”
- EpiPens can become unstable if stored above 25°C, potentially reducing their reliability during life-threatening allergic reactions. Asthma inhalers may also be affected by pressure changes caused by high temperatures.
- People taking diuretics should be particularly careful about fluid loss, which can contribute to dehydration, explains the Express. Ms Phommachanh warned that antihistamines “can have a drying effect on the body and may reduce sweating, which limits the body’s ability to cool itself effectively in high temperatures”.
- Antidepressants such as sertraline and fluoxetine can interfere with the brain’s regulation of body temperature. Certain antibiotics may cause photosensitivity, increasing sunburn risk.
- She advised: “Most medications should be stored in a cool, dry place and definitely speak to a pharmacist if your medicine changes colour, smell, or texture.”
- Read more: Alert for anyone taking 9 common medications over heat wave risk
