Anyone who lives where the weather gets cold in winter knows that you have to prepare a car in the fall. If you forget to put in the antifreeze, you may wake up some chilly morning to discover that your engine block is cracked.
When it comes to medicine, however, people are often oblivious to the damage cold weather can do.
Most pharmaceuticals are supposed to be stored at room temperature, between 68 and 77 degrees Fahrenheit. Brief temperature spikes down to 59 or up to 86 are considered acceptable. But vehicles for the U.S. Postal Service and United Parcel Service have a hard time keeping packages between those limits.
As more and more health insurance companies require their members to order medications by mail, the issue of drug delivery is becoming controversial. Medicines sitting in mailboxes may freeze in the winter and bake in the summer.
One study in St. Louis revealed that the inside of a standard black mailbox can reach 136 degrees on a hot summer day. In other research, investigators mailed 200 drugs from Rockville, Md., to 32 states. More than 90 percent had experienced dangerously high temperatures in transit.
Extreme fluctuations could affect the effectiveness and shelf life of many drugs. Instructions for insulin warn: Do not freeze. Other liquid medications may also be damaged if they are allowed to freeze. And the powerful chemical constituents of some pills may also be altered when subjected to temperatures below 32 degrees.
Mail-order medicines have received the most attention lately, but the problem of exposure to the elements is not limited to drugs left on the doorstep. The trucks that deliver to pharmacies are rarely temperature controlled. Pharmacists tell of receiving liquid prescription medications that have frozen.
If you stop at the pharmacy to pick up a prescription, then leave it in the trunk or the glove box of the car while doing the rest of your errands, your medication could suffer. It is smarter to keep it in the passenger compartment, and then take it with you if you will be in the shopping mall or grocery store long enough for the seat to get cold.
When you travel, make sure you keep your medications in your carry-on luggage. The cargo bay of the plane is not temperature controlled.
Storage at home also deserves your attention. Putting pills in the medicine chest in the bathroom is usually a bad idea. The humidity generated by a shower can shorten the life of antiseizure medications such as Tegretol (carbamazepine). Sunlight can also be a problem, so keep those pill bottles away from window sills.
Today's potent, high-priced pharmaceuticals should be treated at least as well as the family car. Ask the pharmacist about the best way to store your pills, and try not to leave sensitive drugs out in the cold.
Handle with care
Q. I have to take a lot of heart medicine, including nitroglycerin. The home health nurse sets my pills out in a divided plastic box a week at a time. The pharmacist told me that my nitro should not go in this container. Why not?
A. Nitroglycerin needs special handling because it is so volatile. If it is exposed to air or even some kinds of plastic, potency can be lost quickly. Keep nitroglycerin in an airtight container (best is the one the pharmacist gives you) and put the lid back on tightly as soon as you use it.
Write to Joe and Teresa Graedon in care of The Buffalo News, P.O. Box 100, Buffalo, N.Y. 14240.