Heat Wave Warning: 9 Common Medications at Risk
With the Met Office predicting temperatures over 30°C in London this bank holiday weekend, anyone taking certain common medications should be aware that they could become less effective in the heat. The mercury is set to climb significantly from today, Friday, May 22, prompting health warnings about medication storage.
Why Heat Affects Medications
Everyday medicines, including paracetamol and ibuprofen, require storage at temperatures below 25°C. While kitchen cupboards or bedside table drawers are usually suitable, storing medication in cars poses a significant risk. On a 24°C day, the interior of a stationary vehicle can reach approximately 40°C within just ten minutes, according to Right Driver. It is crucial to remove any medication from your car to ensure it remains effective.
Alison Cave, chief safety officer at the Medicines and Healthcare products Regulatory Agency (MHRA), has stated that heat can degrade the active components in medicines, rendering them potentially ineffective. This applies to tablets, inhalers, hormone patches, insulin, and EpiPens. She advises keeping most medicines "somewhere cool, dry and out of direct sunlight," as stated on the packaging. If your medicine changes colour, develops an unusual smell, changes texture, or looks different, it may be heat-damaged. Ask your pharmacist for advice. Heat damage can also affect how much medicine your body absorbs, potentially making your usual dose too strong or too weak. If you notice any changes during hot weather, speak to your pharmacist or doctor.
Medications Vulnerable to Heat
- EpiPens (Epinephrine): Adrenaline is highly sensitive to heat. High temperatures can cause the solution to degrade rapidly and lose potency. If the liquid in the viewing window looks cloudy or pink, it may have been denatured.
- Insulin: Whether in a vial, cartridge, or pen, insulin is a protein. Extreme heat can 'cook' the protein, causing it to break down and fail to control blood sugar.
- Asthma Inhalers: Heat can alter the medication and cause the pressurised canister to warp or leak. In extreme cases, it may burst.
- Nitroglycerin: Prescribed for angina, this medication is known for its instability. Heat causes it to lose potency incredibly fast, which can be fatal if chest pain occurs.
- Paracetamol and Ibuprofen: Intense heat accelerates chemical degradation. They won't become toxic, but they lose potency, making them ineffective for headaches or inflammation.
- Aspirin: Heat breaks it down into salicylic acid and acetic acid. If it smells strongly of vinegar, it has degraded and may cause severe stomach irritation.
- Hormone-based Medications: This includes contraceptive pills, HRT, and thyroid medications. Heat alters their molecular structure, potentially reducing effectiveness.
- Blood Thinners: Temperature spikes can affect medications like warfarin, dangerously altering blood-clotting times.
- Children's Medicines: Liquid medicines like Calpol can ferment, separate, or undergo bacterial growth when incubated in a hot car. Do not use if heat damage is suspected.
For any medication, check the label for recommended storage instructions. Avoid leaving medicines in your vehicle for extended periods. If you have concerns, consult your pharmacist or doctor.
