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The People’s Pharmacy: Don’t leave medicine in the cold

More and more people are getting prescription medicines through the mail. That’s because their insurance companies are encouraging them to use specific mail-order pharmacy services to save money.

This seems like a great idea on the surface, but at this time of year it could pose problems. Cold temperatures and moisture from snow, sleet and rain can affect many medications.

Delivery services such as UPS, FedEx and the U.S. Postal Service do not deliver most packages in temperature- or humidity-controlled vehicles. Your medicine may ride around in freezing weather for hours and then be left in the mailbox or on the doorstep for hours longer.

Why is this a problem? Check the official prescribing information for most medicines and you will discover that they are supposed to be kept within a narrow temperature range (68 to 77 degrees Fahrenheit). Temporary fluctuations of 59 to 86 degrees are usually OK, but in the winter medicine is likely to get much colder than 59 degrees in many parts of the country.

A new alert from the Food and Drug Administration tells why this is so important. Pradaxa (dabigatran) is an anticoagulant pill that helps prevent blood clots and is used to ward off strokes. The FDA warns that Pradaxa capsules must be kept in their original packaging and protected from “excessive moisture, heat, and cold.” That means they should not be allowed to freeze in the back of a delivery vehicle.

Once Pradaxa is delivered to patients, the capsules should not be loaded into a multicompartment pill organizer. Many older people find such boxes helpful to keep their medication regimen straight. They may put pills into a weekly reminder box to keep from skipping or duplicating doses.

The trouble is that these containers are rarely airtight. Consequently, moisture can penetrate. In the case of Pradaxa, this can break down the medication.

Drugs should never be stored in the bathroom medicine cabinet for the same reason. Moisture is the enemy of many medicines. Take a look at the mirror the next time you step out of the shower. If it’s fogged over, you know that the humidity in your bathroom is too high for safe drug storage.

One way to bypass the moisture problem is to use blister packs. Pradaxa is sold in both bottles and blister packs. The blister pack should protect the pills from moisture.

Some companies offer customized bubble packs with every medication organized and listed. That way the patient has the benefits of an easy-to-follow regimen without the pills being exposed to humidity. One such service is This doesn’t solve the problem of freezing in the winter and roasting in the summer, but it does help eliminate the moisture concerns.

Even people who purchase their medicines in a local pharmacy are not home free. If they leave their medication in the glove box, the trunk or on the seat while they do other errands, the changes in temperature may affect their drugs. Liquid medicine may be especially vulnerable.

Now that so many prescriptions have become so pricey, they deserve to be treated like expensive wine or fresh fish. Don’t leave them sitting around where they could deteriorate.

Joe Graedon is a pharmacologist. Teresa Graedon holds a doctorate in medical anthropology and is a nutrition expert. Their syndicated radio show can be heard on public radio. In their column, Joe and Teresa Graedon answer letters from readers. Write to them via their website: