Hot Medicines Turn Old

Medicines left in extremely hot environments can expire

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Here's some info hot off the presses: During extremely hot periods, the temperature in cars can rise to over 160 degrees, and the inside of mailboxes can reach almost that high as well.

Everyone knows or should know, that leaving people and animals in these hot conditions can be quite harmful. But, what about medications exposed to these blistering conditions?

"Protect people, pets and medications from extreme heat."

Amy Peak, Ph.D., director of Drug Information Services for Butler University in Indianapolis, IN, reports that medicines can be harmed by excessive heat. The United States Pharmacopeia Convention Inc. has standards to preserve the quality of medicines.

This organization recommends that all medications should not be exposed to heat over 104 degrees. Peak informs that very few medications are studied at temperatures above the high 80s.

Medications tested in higher temperatures with negative outcomes include:

  • Valium: When stored at body temperature of 98.6, a decrease of 25 percent of the concentration has been recorded.
  • Albuterol Inhalers: Temperatures 120°F and above may burst the inhaler. Also, some studies have shown that higher storage temperatures lead to a decrease in the amount of medication inhaled.
  • Concentrated epinephrine: Heat exposure leads to a 64 percent loss in potency.
  • Formoterol (capsules that are placed in inhalers): After exposure for four hours to almost 160, the amount released from the heated capsules was not even 50 percent of those capsules stored in appropriate temperatures.
  • Lorazepam: When stored at almost 100 degrees, concentration decreased by a very significant 75 percent.
  • Nasonex (formoterol inhalers): Temperatures above 120 degrees may cause the container to burst.

Peak adds other medications that could be adversely effected by tremendous heats include:

  • Any medicine in an aerosolized canister may burst at a heat over 120°F.
  • Thyroid Hormones: Excessive heat may alter these hormones that result in a dose inconsistent with the prescribed dose.
  • Insulin: Excessive heat can make the vials that store insulin to break. Additionally, the extreme heat may alter insulin, making it not comply with the prescribed dose.

Three peak heat suggestions from Peak:

  1. When in the vehicle, don't keep medicines in the trunk. If the air conditioning is on in the passenger compartment, the medicine will be fine.
  2. Never leave your medicine in an unattended, un-air conditioned car.
  3. If delivered via a mail service in extremely hot weather, have medications shipped overnight. Although most mail-order pharmacies ship medications that heat sensitive in cooled containers, in extreme heat, all medications may be altered or even ruined.
Reviewed by: 
Review Date: 
August 10, 2011
Last Updated:
August 10, 2011