WEDNESDAY, Oct. 27, 2004 (HealthDayNews) -- A new study finds that drugs delivered by mail may wilt in the sun and become less effective if they're not retrieved in time.
In the dead of an Arizona summer, a mailbox can reach a parching 158 degrees Fahrenheit, a temperature that Phoenix researchers found had deleterious effects on the asthma drug formoterol.
Exposed to such extreme heat for a prolonged period, capsules of the gelatin-coated powder turn brown and the active ingredient, formoterol, gets clumpy, explained lead investigator Dr. Gregory T. Chu, senior pulmonary and critical care fellow at Carl T. Hayden Veterans Affairs Medical Center in Phoenix.
Further testing showed the heat-exposed medication delivered less than half of its intended dose.
"The genesis of this study was our patients were actually calling us and telling us that that drug was being delivered to them in unsuitable conditions," said Chu, who presented the finding on Oct. 27 the American College of Chest Physicians annual meeting in Seattle.
Inhaled formoterol, sold under the brand name Foradil, is used to treat breathing difficulties in people with asthma and chronic obstructive pulmonary disease (COPD), a condition that includes chronic bronchitis and emphysema. The patient places a powder-filled capsule in a special inhaler that cracks the capsule open, releasing the drug for inhalation.
An estimated 20 million Americans have asthma, and nearly 12 million had had an asthma attack in the previous year, according to the American Lung Association. COPD, the nation's fourth leading cause of death, claims 117,522 lives in the United States each year.
With more Americans than ever receiving prescriptions by mail, some medication safety experts worry that exposing certain medications to extreme heat or cold could render the drug ineffective. Their concern is not limited to prescriptions received by mail or to formoterol, the focus of the VA hospital study.
"This is far more broad than what they present it to be," said Matthew Grissinger, a medication safety analyst at the Institute for Safe Medication Practices, a Pennsylvania-based drug safety organization.
Every prescription comes with information indicating the safe temperature for storing that medication, he noted. While some medications must be refrigerated; others should be kept at room temperature.
"Any time you exceed that temperature, there's no guarantee what you're going to get," Grissinger said.
But Ann Smith, a spokeswoman for Medco Health Solutions, which dispensed 78 million mail order
prescriptions in 2003, said the study fails to mention safe packaging requirements.
A mail order pharmacy such as Medco has procedures in place for temperature-sensitive medications, including formoterol, she said. Such medications are shipped overnight in insulated packaging including ice or cold gel packs, depending on the type of medication and seasonal weather conditions.
To test the effects of heat on medications delivered by mail, Chu and his colleagues recreated the conditions of a scorching Arizona mailbox in their lab. Formoterol capsules, still in their original blister packaging, were heated to 70 degrees Celsius (or 158 degrees Fahrenheit) for four hours.
On inspection, the heated capsules appeared grossly distorted and the formoterol formed clumps, the authors reported.
The team also tested the effectiveness of the medication by dispensing the heated capsules into a filter tube using the inhalation technique and device provided by the drug's manufacturer. The weights of filter paper used before and after dispensing the heated capsules were compared with the same measurements for capsules that were not heated.
Filter weights used with the heated capsules were less than half of those obtained from capsules that had not been heated. That suggests the heated capsules delivered significantly less medication than intended, the authors concluded.
Any hot environment -- a car or transport truck -- could pose a danger, Chu cautioned.
And, as Grissinger pointed out, one of the worst places to keep prescriptions is the medicine cabinet: "Think about the heat and humidity in the bathroom."
More information
For more tips on safe medication use, visit the National Council on Patient Information and Education.
