The Risks of Medication Combinations During Heatwaves

As summer unfolds, Germany is experiencing increasing heatwaves, defined by the German Weather Service (DWD) as periods of three consecutive days ranking among the hottest 2% of recorded days for that region. Despite a number of rainy days, the summer of 2024 was on average 2.2 °C warmer than the reference period of 1961 to 1990. Notably, the years 2015 and 2022 saw particularly severe heatwaves.

Heatwaves are linked to increased emergency room visits, hospital admissions, and heat-related fatalities. In 2015 alone, approximately 5,200 deaths in Germany were attributed to heat, a figure that rose to 8,100 in 2022. With a rate of 98 heat-related deaths per million residents, Germany finds itself in the middle range among European countries, lagging behind nations like France, which have reportedly implemented more effective protective measures.

The human body has various mechanisms to adapt to a wide range of temperatures. Typically, the thermal comfort zone ranges from 19 to 26 °C, though this varies individually and is influenced by factors such as humidity. When temperatures exceed this comfort range, the body initiates thermoregulation, resulting in increased sweating, enhanced skin blood flow, and elevated heart rates.

Heat can pose significant health risks. Ranging from minor conditions like heat rash to severe and potentially fatal heatstroke, the body's adaptive responses can lead to dehydration, hypovolemia, and hyperosmolality, which stress various organ systems. Increased peripheral blood flow can cause heat edema in the ankles and lower legs or lead to heat collapse.

Prolonged exposure to high temperatures can trigger heat exhaustion, characterized by weakness, discomfort, dizziness, and body core temperatures exceeding 40 °C, though it does not typically present serious neurological symptoms. On the other hand, heatstroke can result in a core temperature above 40 °C, altered consciousness, and possible seizures, necessitating immediate medical intervention.

Given the rising temperatures and their potential impacts on health, it is critical for vulnerable populations, including the elderly and those with preexisting health conditions, to be aware of the risks associated with medication combinations during heatwaves. Specifically, the interaction between beta-blockers and non-steroidal anti-inflammatory drugs (NSAIDs) can compound the dangers posed by high temperatures. Pharmacists and healthcare providers are encouraged to counsel patients on the importance of staying hydrated and monitoring for adverse effects during these extreme weather conditions.

As heatwaves become more frequent and intense, public health responses must prioritize the needs of at-risk populations and implement strategies to mitigate the health impacts of extreme temperatures.