Medications and Heat: What Pharmacists Should Know

Some medications can interact with hot weather and increase the risk of heat‑related illness. This is especially concerning for older adults, who are more likely to take two or more of these medications at the same time. The CDC has described certain medications that can interact with heat and outlined ways clinicians can help. Some examples include:

1. Diuretics (e.g., furosemide, hydrochlorothiazide) increase fluid loss and can lead to dehydration, electrolyte imbalances, and dizziness.

2. ACE inhibitors and ARBs (e.g., lisinopril, losartan) can reduce thirst sensation and contribute to low blood pressure during hot weather.

3. Beta‑blockers (e.g., metoprolol, propranolol) reduce the body’s ability to increase blood flow to the skin and may decrease sweating, making it more difficult to cool down.

4. Calcium channel blockers (e.g., amlodipine, nifedipine) can worsen low blood pressure and increase the risk of fainting in the heat.

5. Anticholinergic medications (e.g., diphenhydramine, promethazine) impair sweating and interfere with the body’s ability to regulate temperature.

6. SSRIs and SNRIs (e.g., sertraline, duloxetine) may increase sweating or, in some individuals, impair the body’s cooling mechanisms.

7. Antipsychotics (e.g., quetiapine, risperidone) can interfere with the body’s central temperature regulation and sweating.

8. Nonsteroidal anti‑inflammatory drugs (NSAIDs) (e.g., ibuprofen, naproxen) may increase the risk of kidney injury when dehydration occurs.

9. Medications that increase sun sensitivity, such as tetracyclines, fluoroquinolones, and metronidazole, can increase the risk of sunburn.

How pharmacists can help older adults stay safe during hot weather

1. Reviewing medications to identify those that may increase the risk of heat‑related illness.

2. Counseling patients not to stop or adjust their medications without first speaking with their healthcare provider and developing an appropriate plan.

3. Advising patients to reduce sun exposure if taking medications that increase sun sensitivity, including wearing protective clothing and using sunscreen with an SPF of 30 or higher.

4. Adjusting fluid restrictions during periods of extreme heat, particularly for patients taking medications that increase the risk of dehydration or electrolyte imbalance.

5. Providing guidance on proper medication storage during hot weather. For example, insulin should be refrigerated, as excessive heat can reduce its effectiveness.

Learn more by visiting the CDC’s Heat and Medications – Guidance for Clinicians.