Medicines and hot weather: unexpected effects, reactions and how to store them when travelling. Here is the list

“In extreme cases, and only on the advice of a doctor, a change in treatment may be considered,” explains AIFA, which then goes on to list the individual cases. Antihistamines, for example, can inhibit sweating. Antipsychotics and antidepressants, as well as anti-Parkinson’s drugs, can lower blood pressure.

Anxiolytics and muscle relaxants may exacerbate feelings of exhaustion, cause dizziness or aggravate respiratory problems. Beta-blockers and vasodilators may affect the body’s ability to dissipate heat, increasing the risk of hypotension and dehydration.

Diuretics can contribute to excessive loss of fluids and electrolytes. Another recommendation concerns photosensitisation-induced skin reactions: antibiotics, topical anti-inflammatories and corticosteroids can cause skin rashes or erythema when combined with exposure to UV rays. “If you are taking these medicines, you should protect yourself with sun cream and light clothing.”

As well as managing treatment, another important aspect concerns correct storage. High temperatures can, in fact, alter the chemical and physical stability of many molecules, rendering them ineffective or even dangerous. In particular, insulin, hormones and vaccines must be stored at controlled temperatures, often between 2 and 8 °C.

In summer, never leave medicines in the car or in direct sunlight.

When travelling, it is advisable to use cool bags or insulated containers. When travelling by plane, essential medicines must be carried in your hand luggage, together with your prescription.

If a medicine changes colour, smell or consistency, it is important not to take it.

Where possible, it is best to “choose tablets or capsules rather than liquid solutions”, as they are more stable at high temperatures. Finally, it is good practice to “always store medicines in their original packaging, which protects them from light and moisture and contains all the necessary information”.

AIFA also identifies the categories of medicines which, depending on how they interfere with the effects of heat, may exacerbate the impact of high temperatures on health.

Here is the list: Anticholinergics: may interfere with thermoregulation, reduce alertness and inhibit sweating Antipsychotics: may inhibit the sweating mechanism, lower blood pressure and impair central thermoregulation, and reduce alertness, rendering the individual unable to adopt defensive strategies Antihistamines: may inhibit the sweating mechanism and lower blood pressure Anti-Parkinson’s drugs: may inhibit the sweating mechanism and lower blood pressure, causing dizziness and confusion Antidepressants: may reduce sweating, interfere with central thermoregulation and reduce alertness. Anxiolytics and muscle relaxants: may reduce sweating and cause dizziness, decrease cardiac output and affect cooling via vasodilation; they may exacerbate respiratory symptoms Antiadrenergics and beta-blockers: may affect the dilation of cutaneous blood vessels, reducing the ability to dissipate heat by convection Sympathomimetics: vasodilators, including nitrates and calcium channel blockers, may worsen hypotension in susceptible individuals Antihypertensives and diuretics: may lead to dehydration and reduce blood pressure; a common side effect is hyponatraemia, which may be exacerbated by excessive fluid intake Antiepileptics: may reduce alertness and increase confusion.