The Medicines and Healthcare products Regulatory Agency (MHRA) has issued critical guidance for individuals taking antibiotics, diuretics, or antidepressants as the UK experiences temperatures above 30°C. Hot weather can alter how your body responds to medication, potentially affecting those managing long-term conditions. Simple measures can help prevent complications.
Key Advice from the MHRA
Alison Cave, the MHRA's Chief Safety Officer, stated: "Let's face it - when there's a heatwave, most of us are focused on getting outside and enjoying it while it lasts. But it's easy to forget that medicines left in the heat - in cars, bags, or on sunny windowsills - might not work properly when you need them."
Certain everyday medicines can make your skin significantly more susceptible to burning, even in moderate sunshine. These include some antibiotics, diuretics, antidepressants, or skin treatments for acne or eczema. Painkillers such as ibuprofen or naproxen may occasionally trigger mild sun sensitivity, though this is less frequent and generally only a concern with regular or prolonged use.
Methotrexate and Sun Sensitivity
One medication requiring particular attention is methotrexate, prescribed for conditions including rheumatoid arthritis, psoriasis, Crohn's disease, and cancer. It can cause extreme skin sensitivity to the sun, even at low doses, leading to painful rashes, blistering, or swelling resembling severe sunburn. In rare cases, these reactions have resulted in serious infections. Always read the patient information leaflet or consult your pharmacist to check if sun sensitivity is a side effect.
Practical Tips from Well Pharmacy UK
Well Pharmacy UK echoes this advice on TikTok: "Hot weather can affect both you and your medication." They recommend:
- Check medicine storage instructions
- Keep medication out of direct sunlight
- Stay hydrated
- Protect your skin with SPF, shade, and light clothing
Alison summarised: "To stay safe in the heat: Store medicines somewhere cool, dry and out of direct sunlight – especially if you’re out and about. Know the signs of heat-related illness – stay hydrated and listen to your body. Take extra care in the sun if your medicine makes your skin more likely to burn. And remember, for all medicines it’s important to read the leaflet and speak to a healthcare professional if you have any questions."
Medical Devices Also Affected
Medical devices should not be overlooked, as extreme heat can damage them. The MHRA cautions: "It's not just medicines - some medical devices can also be affected by heat or humidity. For example, blood glucose monitors may give people managing diabetes less reliable readings if used or stored in hot conditions." Keep devices and test strips somewhere cool and dry, and check the instructions for temperature guidance. If your device isn't behaving as expected, run a control check or speak to your pharmacist for advice.
