The NHS has issued a warning regarding a range of medications that could make individuals unwell during the ongoing heatwave, with some posing a risk of serious health complications. As much of the UK experiences unusually high temperatures for May, health officials have published a comprehensive list of medicines that may impair the body's ability to cope with heat.
Consult a professional before making changes
While it may not be feasible to discontinue a medicine entirely, lowering the dosage might be possible. However, the NHS strongly advises consulting a pharmacist, GP, or nurse before making any adjustments to medication regimens.
How medications affect heat tolerance
According to the NHS, various types of medication can impair the body's ability to regulate temperature, affect perspiration and hydration levels, cause elevated body temperature, drowsiness, and potentially lead to organ damage through dehydration. This follows guidance from the Medicines and Healthcare products Regulatory Agency (MHRA) and Well Pharmacy UK, which encouraged residents to be mindful of where medication is stored during the heatwave. Antibiotics, diuretics, and antidepressants can lose effectiveness when exposed to heat and may increase skin sensitivity, raising the likelihood of sunburn.
Medicines affecting sweat production
Perspiration is the body's natural cooling mechanism. The NHS warns that the following medicines can impair sweat production:
- Beta blockers such as metoprolol or bisoprolol, used for heart conditions and high blood pressure.
- Decongestants like pseudoephedrine, found in cold medications.
- Anticholinergic medicines, including some allergy medications (diphenhydramine), sleeping pills, urinary incontinence treatments (oxybutynin), and antidepressants (amitriptyline or nortriptyline).
Medicines that can cause dehydration
Dehydration occurs when the body lacks sufficient fluid to function properly. Serious dehydration requires urgent medical care. Medications that heighten dehydration risk include:
- Diuretics (water tablets) such as hydrochlorothiazide and furosemide, laxatives, and some diabetes medicines like canagliflozin or empagliflozin, which increase fluid loss.
- Antidepressants such as fluoxetine and venlafaxine, which cause excessive sweating.
Medicines that raise body temperature
Certain medications can interfere with the body's temperature control, becoming particularly challenging during a heatwave. These include:
- Antipsychotic medications like olanzapine or quetiapine.
- Stimulant medications for attention disorders such as methylphenidate.
Medicines that cause drowsiness
Some medications induce drowsiness, affecting concentration and reaction times, making it harder to stay cool and hydrated. These include:
- Anti-anxiety or insomnia medicines such as benzodiazepines (lorazepam or oxazepam).
- Nerve pain medications like pregabalin and gabapentin.
- Opioid pain medications such as morphine and codeine.
Medicines increasing organ damage risk via dehydration
Using certain medications while dehydrated can reduce blood flow to vital organs. These include:
- Anti-inflammatory medications like ibuprofen or naproxen.
- Blood thinners used to prevent clots.
- Medications for high blood pressure.
- Diabetes medications including metformin.
- Lithium for bipolar disorder.
Always consult a healthcare professional before altering any medication regimen, especially during extreme weather conditions.
