Overview
- The MHRA re‑issued its guidance on 26 June and has re‑emphasised the advice as UK temperatures are forecast to climb above 30°C this week.
- The agency warns that heat can break down active ingredients so most medicines should be stored below 25°C and refrigerated products are especially vulnerable.
- The guidance highlights that some drugs change how the body copes with heat, naming ACE inhibitors such as ramipril and beta‑blockers such as bisoprolol and also citing insulin, metformin, antipsychotics, stimulants and diuretics.
- Practical steps from the MHRA and charities include keeping medicines in a cool, dry place out of direct sunlight, never leaving them in hot cars or bags, staying hydrated, knowing signs of dehydration and checking with a GP or pharmacist before altering treatment.
- Older people, young children and people with heart, kidney or chronic conditions face the greatest harm from reduced drug effectiveness or heat‑related dizziness and dehydration, which could lead to missed doses, falls or extra demand on NHS services.