The National Authority of Medicines and Health Products (Infarmed) offers guidance on its website through the document “Medicines and Heat,” addressing frequently asked questions and providing “useful advice” and guidelines to maintain the effectiveness of medications.
Infarmed emphasizes that “exposure to high temperatures can compromise the safety and efficacy of medicines,” noting that drugs such as diuretics, antidepressants, antihypertensives, or antipsychotics can interfere with the body’s thermal regulation mechanisms.
“This situation is particularly relevant for the elderly, chronic patients, obese individuals, children, and bedridden people, who find it harder to adapt to the heat,” it highlights.
The head of Infarmed’s Directorate of Risk Management of Medicines (DGRM), Márcia Silva, explains that “in most cases, medicines do not by themselves represent a risk factor, especially when used correctly according to the doctor’s or pharmacist’s instructions.”
However, she warns, “there are several health-related risk factors that interfere with the body’s ability to regulate temperature and consequently reduce the capacity to withstand heat, which need to be monitored.”
According to Infarmed, medicines should be stored and transported as indicated in the package leaflet, as heat can alter medicine properties.
“Medicines requiring refrigeration (between 2°C and 8°C) should be transported in refrigerated isotermic bags, without being frozen. Others should also be protected from high temperatures,” it advises.
The medication authority advises patients not to stop treatments without medical guidance during a heatwave, as this decision “can lead to serious complications related to the sudden cessation of taking medications as well as the untreated disease’s effects.”
It also recommends those on medication to avoid consuming alcoholic beverages, as they aggravate dehydration, and “to not take any medication without the guidance of a doctor or pharmacist, even those that are over the counter.”
The Portuguese Institute for Sea and Atmosphere (IPMA) forecasts a temperature rise starting on Thursday, particularly from Friday, with maximum temperatures reaching above-average values for the season, “beginning to contribute to a heat wave at least until the 30th.”
“A significant increase in air temperature is expected from the 24th, Thursday, with maximum temperatures above 30°C across most of the mainland, reaching 40°C in some locations, notably in the southern interior region and the Tagus valley,” states a communiqué on their website.
According to the IPMA, the minimum temperature should exceed 20°C in some interior locations, particularly in the southern region, Tagus valley, and Beira Baixa region.
