Keeping Medication Safe in the Heat

Introduction

Keeping medication safe in the heat is a practical part of safe patient care during warmer weather. Hot conditions can affect medicines and how well they work and can also change how patients respond to them. This is particularly relevant for those managing long-term conditions, and a few straightforward steps can help reduce avoidable harm.

How Heat Affects Medicine Efficacy

Most medicines need to be stored at temperatures below 25°C. Heat can break down active ingredients, meaning a medicine may not work properly when a patient needs it.

This applies across tablets, inhalers, hormone patches, insulin and EpiPens. Some packaging carries clear storage instructions, but not all medicines come with a visible warning.

Medicines that require refrigeration, such as insulin or certain liquid antibiotics, are especially vulnerable. If they are left out too long or stored incorrectly, they may not work as intended.

Heat damage can also affect how much medicine the body absorbs, potentially making a usual dose too strong or too weak.

If a patient reports changes in how they feel, or in how well their medicines seem to be working during hot weather, advise them to speak to their pharmacist or doctor.

Storage Away from Heat and Direct Sunlight

Vehicles such as cars, trains and buses heat up quickly in summer, and rooms with direct sunlight can become much hotter than expected. Even bags and pockets can be warm enough to cause problems, particularly when patients are out for a full day.

The patient information leaflet should be checked for storage instructions, and medicines kept in the coolest available area, away from direct sunlight.

Recognising Heat-Damaged Medicines

A medicine that has changed colour, developed an unusual smell, changed texture, or looks different in any way may have suffered heat damage.

Medical Devices Are Also at Risk

Heat and humidity can affect some medical devices, not just medicines. Blood glucose monitors, for example, may give less reliable readings if used or stored in hot conditions.

Devices and test strips should be kept somewhere cool and dry, with the manufacturer’s instructions checked for temperature guidance. If a device is not behaving as expected, a control check or pharmacist advice is the appropriate next step.

Identifying Patients at Risk of Dehydration

In hot weather, the body loses more water through sweating, and several medicines can worsen this or impair the body’s ability to cope with heat.

Patients taking diuretics, or water tablets such as furosemide, are already losing more fluid through urination, which can cause dehydration and mineral imbalances.

Blood pressure medicines such as ACE inhibitors, beta-blockers or calcium channel blockers can make temperature regulation harder. ACE inhibitors can also suppress the natural thirst response.

Some diabetes medicines, including insulin and metformin, can increase dehydration risk or make early symptoms harder to spot. Antipsychotics such as olanzapine or quetiapine, and stimulant medications, can raise body temperature and increase the likelihood of overheating.

Dehydration can present as dizziness, headaches, tiredness, confusion and dark urine. This is particularly dangerous for older adults, young children, and people with heart or kidney conditions.

A patient who becomes unwell in the heat should be moved somewhere cooler and given water to sip slowly, with medical advice sought promptly if they do not improve.

Medicines That Increase Sunburn Risk

Some common medicines can make skin much more likely to burn, even in mild sunshine. These include some antibiotics, diuretics, antidepressants, and skin treatments for acne or eczema.

Painkillers such as ibuprofen or naproxen can sometimes cause mild sun sensitivity, though this is less common and usually only a concern with frequent or long-term use.

Methotrexate warrants particular attention. Used for conditions such as rheumatoid arthritis, psoriasis, Crohn’s disease and cancer, it can cause extreme skin sensitivity to the sun even at low doses.

This can lead to painful rashes, blistering or swelling resembling severe sunburn. In rare cases, these reactions have progressed to serious infections.

The risk rises during sunny weather, especially when patients are outdoors more often. Even brief exposure can be enough to trigger a reaction in some people.

For any patient on medication, the patient information leaflet should be checked, or a pharmacist consulted, to confirm whether sun sensitivity is a listed side effect.

Conclusion

Keeping medication safe in the heat rests on a few consistent practices: storing medicines somewhere cool, dry and out of direct sunlight, supporting patient hydration, and taking extra care with patients, whose medicines raise their burn risk.

For all medicines, the patient information leaflet should be read, and a healthcare professional consulted where any questions arise.

Citation
Source: https://www.gov.uk/government/news/dont-let-this-heatwave-affect-your-medicines-three-important-tips-from-the-mhra