If you’ve ever taken a medication – whether prescription or over-the-counter drugs like Advil – you’ve likely read the labeling instructions for proper storage. Many medications’ labels recommend storage at room temperature, as well as avoiding excess temperatures, above 104°, for example. But what happens when medications are stored above room temperature, particularly in the extreme heat of the summer?

Car interiors can rise to over 160°, which can be especially harmful to your medications.

Amy Peak, Director of Drug Information Services for Butler University, tells TheDoctor that "the technical definition of room temperature is general storage between 68 and 77 degrees F, but also allowing for temporary excursions as low as 59 degrees F, and as high as 86 degrees F." Experts say that storing medications over 86° – a fairly typical summer temperature in many areas of the country – can have a significant effect on their potency. And, depending on where you live, summer temperatures can rise to over 100° indoors, if you don’t have air conditioning. What’s worse, car interiors can rise to over 160°, which can be especially harmful to your medications.

For example, when stored over 98°, lorazepam and diazepam decrease potency by 75% and 25%, respectively. Albuterol inhalers for asthma can explode when stored in temperatures over 120°; even in moderately high temperatures, they deliver less of the chemical than when they are stored at room temperature. In fact, any medication that is contained in an aerosolized container can explode in temperatures over 120°.

Insulin and thyroid hormones are also sensitive to heat, and can lose effectiveness in high temperatures. Concentrated epinephrine can lose potency by 64% when exposed to cyclical heating (repetitive heating and cooling).

Peak offered some specific tips for keeping medications safe and cool in the summer months:

  • Do not place medications in an area of sunlight (especially not in a windowsill)
  • Do not store medications in an area of high humidity (for example, avoid storing in a bathroom with a shower or bathtub, or in a kitchen cabinet near the dishwasher)
  • If possible, store medications in the coolest area of the house (potentially a basement or a "power room" without windows)
  • Take a minute to look at your medications before you take them. If they are stuck together in the bottle, if they have any changes in form or shape, or coating appears different or "runny" — the integrity of the medication may have been compromised. (However, note: you often cannot tell there is a problem just by looking. If you can visually see a change, the integrity is likely to be compromised, but the opposite isn’t true. There can still be a decrease in potency/effectiveness even if you can’t see a notable difference in the outside of the product.)

And, of course, don’t leave your medications inside hot cars: take them with you if you leave the car, even briefly. When you’re traveling with them, keep them in the climate-controlled interior of the car, rather than in the hot trunk. If you’re having medication shipped to you in the summer, have it over-nighted, if possible. Sometimes insurance companies will do a one-time replacement if you believe your medication has been affected by extreme heat.

If you live in particularly hot climates and do not have air conditioning, you may want to consider keeping your meds in the refrigerator, but consult a pharmacist to make sure this is safe. Peak says, "If the alternative temperature is extreme (for example > 105 F), the danger of the extreme heat altering the medication is probably greater than the risk of the cool temperature altering the medication. However, there are some medications, especially certain liquid medications, that are not recommended to be stored in the refrigerator because they may become too viscous, separate, or become ‘clumpy.’"

Again, always check with your doctor or pharmacist about the most practical way to store your specific medication.

Special thanks to Amy Peak, clinical pharmacist and Director of Drug Information Services at Butler University College of Pharmacy and Health Sciences.