Medications can be harmed by excessive heat

We all know that people and animals can be harmed by excessive heat; so can medications, states Dr. Amy Peak, director of Drug Information Services for Butler University.

Already this summer, air temperatures have risen above 100°F in many states. During extreme heat, temperatures in dark-colored cars can reach as high as 163°F, and temperatures inside mailboxes can be as high as 158°F.

The United States Pharmacopeia Convention Inc. (USP)sets standards to ensure the quality of medications and recommends that all medications be protected from excessive heat, which is defined as 40°C (104°F). But Peak says only a few medications are ever studied at temperatures above 86°F.

Medications with documented exposure to high temperatures include:

• Albuterol Inhalers: Temperatures above 120°F may cause the container to burst. Additionally, studies have shown a decrease in the amount of medication delivered per use as storage temperature increased.

• Concentrated epinephrine: When exposed to cyclical heating, lost 64 percent of original potency.

• Diazepam: When stored at 98.6°F, concentration decreased 25 percent.

• Formoterol (capsules that are placed in inhalers): After being heated to 158°F for four hours, the amount released from the heated capsules was less than half of the amount released from the capsules stored in normal conditions.

• Lorazepam: When stored at 98°F, concentration decreased 75 percent.

• Mometasone (formoterol inhalers): Studies have shown that when exposed to temperatures above 120°F the container may burst.

Peak says other medications that may be problematic include:

• Insulin: Excessive heat may alter insulin, potentially making it less effective. Additionally, extreme heat may make the volume of insulin inside the vials expand, possibly causing the vials to break.

• Thyroid Hormones: Excessive heat may alter the thyroid hormone resulting in an inconsistent dose.

• Any type of medication in an aerosolized canister could burst when exposed to heat over 120°F.

So, what is a person to do during these times of extreme heat? Peak offers three suggestions:

1) When in the vehicle, keep medications in the climate-controlled passenger compartment, not in the trunk.

2) When you exit your car, ALWAYS take your medications with you.

3) If medications are delivered to you in extremely hot weather, have them shipped overnight if possible. Most mail-order pharmacies ship a small number of medications that are clearly known to be temperature sensitive in special cooled containers. But, in the most extreme heat, all medications have the potential to be altered.

Peak says if you think your medication has been compromised due to heat to call your insurance company and ask for a one-time replacement. If they decline the replacement, you should contact the drug manufacturer. A pharmacist is a great resource to help a patient find a drug manufacturer's toll-free number.

Source Butler University