We all know medications can have undesired side effects, particularly for individuals with multiple daily prescriptions. Usually, adverse drug events (ADEs) are evident within 48 hours of adding or increasing the offending medication. However, with some medications, it depends on the weather. Many common medications increase sensitivity to excessive heat. That means medications taken without issues throughout other seasons may increase ADE risk now that we’re in summer.
Medications can contribute to heat sensitivity through several mechanisms. Guidance from the CDC highlights the following risks:
- Common medications for high blood pressure and heart failure can reduce thirst, leading to dehydration. These include Angiotensin II receptor blockers (ARBs), ACE inhibitors, and diuretics.
- Antipsychotics, stimulants, and anticholinergics, including medications for Parkinson’s and bladder control, can interfere with the body’s internal temperature regulation.
- Common antidepressants (SSRIs and SNRIs) may increase sweating, leading to dehydration.
- Excessive heat increases the risk of dehydration and volume depletion, which can reduce the body’s ability to clear medications, leading to higher concentrations. Medications with a narrow therapeutic index can be especially problematic.
- Transdermal medications may be absorbed faster, increasing the risk of overdose. This can be especially dangerous with fentanyl.
- Some medications are heat-sensitive, leading to reduced effectiveness if not stored properly.
Staying in an air-conditioned room is the safest option during periods of extreme heat, but one in 10 U.S. households lacks air conditioning. In areas with historically mild weather, air conditioning is rare, leading to heightened mortality when heatwaves do occur. Many lower-income Americans avoid using their air conditioners because of the cost of electricity. When air conditioning is unavailable or inadequate, closing curtains and maintaining adequate ventilation can keep homes cooler. Ice packs and wet washrags can help patients better cope with the heat. Use of protective clothing and broad-spectrum sunscreen are essential if exposure to sun is desired or unavoidable, particularly because many medications can increase sensitivity to sunlight.
Hospice teams should screen for heat preparedness during the admissions process and educate patients and caregivers about the symptoms of heat. It is also advisable to check in between home visits. Ensuring adequate hydration should be a top priority whenever possible. In some cases, medication adjustments may be required. Pharmacists are an essential resource when assessing each patient’s risk of heat-related side effects.
