These include drugs widely used for many common conditions, including blood pressure, asthma, depression and allergies, among others. When the temperature rises, they can impair the body’s ability to cope with heat.
“Everyone who takes medications, whether they are over-the-counter or prescription, needs to consider that their medication can put them at risk once summer arrives,” says Aaron Bernstein, a pediatrician and interim director of the Harvard T.H. Chan School of Public Health’s Center for Climate, Health and the Global Environment.
“Heat waves are getting worse with climate change,” Bernstein says. “We need to be mindful when medications mix with heat. Too much heat can make an otherwise safe and effective drug dangerous.”
Some medicines, such as diuretics, make our bodies lose water, which can result in dehydration when it’s hot outside. Others — such as beta blockers or ACE inhibitors — lower blood pressure, which makes fainting more likely in the heat. Selective serotonin reuptake inhibitors — commonly prescribed antidepressants like Prozac — can make us sweat more, also causing dehydration.
Still others — the OTC allergy drug Benadryl, for example, Cogentin, a medication for Parkinson’s disease, and Spiriva, an asthma treatment — can reduce sweating, the body’s natural cooling mechanism, which can lead to overheating and heat stroke. Finally, others — antipsychotics, for example — can hamper the brain’s ability to regulate body temperature.
Consumers can protect themselves by taking the same precautions as those recommended generally to prevent heat sickness. These include monitoring weather forecasts and — if you exercise outside — go out early in the morning or evening.
“If you have to be outside in the middle of the day, try to stay in shade and drink fluids,” Bernstein says, and seek medical help if you stop sweating or you begin to feel tired or sleepy, signs of heat exhaustion or heat stroke.
“Due to the lack of research in the field, it is impossible to estimate the scale of the problem,” Zhang says. “However, it is for sure that climate change will bring more health problems due to medications. Older people will be especially vulnerable because they usually take more than one drug.”
Bernstein agrees on the need for more research.
“We would be able to do much more in terms of adjusting and advice if we spent a little more time and money figuring this out,” he says.