### Rising Temperatures Prompt Health Watchdog to Issue Medication Warning for UK Residents
As the United Kingdom braces itself for yet another spell of soaring temperatures, a warning has been sounded by health authorities regarding the use and storage of common medicines during a heatwave. The Medicines and Healthcare products Regulatory Agency (MHRA) has highlighted how hot weather can not only affect the efficacy of many everyday medications, but might also increase the likelihood of side effects, including sunburn, dizziness and dehydration, particularly among those living with chronic health problems.
Alison Cave, the MHRA’s Chief Safety Officer, emphasised the importance of being cautious with medicines during periods of extreme heat. “It’s easy to get caught up in making the most of a rare hot spell,” she explained, “but we urge everyone to remember that medicines exposed to heat — whether left in a car, handbag or on the windowsill — may not work as intended when needed most.” This timely reminder is especially pertinent for millions who regularly take medication for conditions such as asthma, heart disease or diabetes.
Medications that are sensitive to sunlight and heat can become less potent, and in some cases, entirely ineffective. This is not limited to tablets but extends to inhalers, hormone patches, insulin and emergency devices like EpiPens. The active ingredients in these products can break down when exposed to high temperatures, potentially causing unpredictable results. The MHRA advises storing medicines in a cool, dry place away from direct sunlight and recommends using cool bags when out and about, particularly at festivals, on the beach or travelling on trains and buses where temperatures can quickly climb above recommended storage guidelines.
Another crucial message revolves around medicines requiring refrigeration, such as certain antibiotics and insulin. If these are left unrefrigerated, there is a genuine risk they could lose their effectiveness or become unsafe to use. Any noticeable changes in appearance, smell or texture of a medication should be treated as a warning sign; in such cases, health professionals advise seeking guidance from a pharmacist before continued use.
Apart from medicines, heat can also interfere with the functioning of medical devices. For those managing conditions like diabetes, it’s noted that blood glucose meters and test strips can become unreliable if exposed to elevated temperatures. The MHRA recommends keeping all equipment dry, cool and following any storage directions provided in device instructions. Should a device show erroneous readings during hot weather, a control test or a visit to the pharmacy is advised.
Dehydration is another significant risk for individuals taking specific medication classes such as diuretics, common blood pressure medicines (including ACE inhibitors, beta-blockers and calcium channel blockers), and some diabetes treatments like insulin and metformin. These medicines can make it more challenging for the body to maintain its fluid balance, heightening the risk of headaches, confusion, dizziness or fainting. In particular, this is concerning for older people, young children and those with heart or kidney conditions. Health authorities stress the importance of recognising early signs of heat-related illness, maintaining hydration and seeking medical help promptly if symptoms of dehydration occur.
Additionally, a number of widely used drugs are known to make individuals considerably more prone to sunburn. This group includes certain antibiotics, antidepressants, diuretics and even some anti-inflammatory painkillers like ibuprofen or naproxen, albeit typically upon prolonged or frequent usage. Methotrexate—a medicine used for autoimmune conditions and some cancers—is flagged for its particularly strong potential to cause skin sensitivity, at times resulting in blistering or rashes after even limited sun exposure.
With people spending more time outdoors in warmer weather, the likelihood of such side effects increases. Experts advise all patients to pay close attention to the information leaflets provided with their medicines and to consult their pharmacist about any concerns relating to sun sensitivity, especially before engaging in extended outdoor activities.
The MHRA invites anyone with queries about their medicines or devices, or concerns about adverse reactions, to consult the agency’s website or use the Yellow Card reporting scheme. In a nation where millions rely daily on prescribed medicines, this comprehensive advisory underlines the hidden risks posed by rising temperatures — and the value of vigilance for all.