People’s pharmacy: Are mail-order medicines ruined by weather?

Q. I read your column concerning pharmaceutical drugs left in a cold mailbox in the winter. A few years ago, I measured summer temperatures in our mailbox with an accurate electronic thermometer.

I was concerned that my drugs might be damaged by the very high temperatures in Tempe, Arizona. The mail is delivered in the afternoon when the sun hits the mailbox.

The temperature of the mailbox was significantly higher than the air temperature. The average daily mailbox temperature between August and October was 121 degrees. Clearly, those high temperatures would be expected to have some effect on many drugs.

Since doing that project, I stopped having my drugs sent by mail and use an in-store pharmacy. Neither the drug companies nor the Food and Drug Administration seemed to provide helpful information when I asked them about this problem.

A. Your information is fascinating. On some days, the temperature in your mailbox reached 130 to 140 degrees. That is way outside the acceptable storage range, even for a short period of time. Guidelines for medications generally call for storage at room temperature (68 to 77 degrees). During shipping, temporary fluctuations are allowed between 59 and 86 degrees; even on the coolest days of your two-month project, your mailbox hit at least 95 degrees.

Some medications could deteriorate rapidly under such conditions, including certain drugs for asthma, diabetes, thyroid and anxiety. Mail-order pharmacies and the FDA need to address this weakness in our drug delivery system.

Q. I went on metformin when my HbA1c went up to 6.2. After three months on this drug, it dropped to 5.9.

I was nauseated and had stomach cramps at first. A few days later, I started having bad diarrhea and then heartburn. My latest symptom is feeling like my bladder is full, and when I go to empty it, there is only a drop of urine. I’ll go back soon to have my kidneys and my HbA1c checked.

I want to get off this medication to start feeling like myself again. Is there any way to do that?

A. HbA1c is a way of measuring average blood sugar levels over a couple of months. Your levels represented prediabetes.

Metformin is the most commonly prescribed drug to treat Type 2 diabetes. Doctors also may prescribe it to prevent high blood glucose levels from turning into diabetes.

Some people cannot tolerate the side effects of this medication. Common adverse reactions include heartburn, gas, diarrhea, nausea and stomachache. Kidney function should be monitored, as metformin can be dangerous for people with compromised kidneys.

Q. I have IBS, controlled with two to four loperamide pills per day. My nearest pharmacy is a two-hour round trip. Limiting my purchase of Imodium will mean spending the rest of my life commuting to the drugstore.

How can I let the Food and Drug Administration know that the proposed restrictions are ill-advised? If they really wanted to protect people from dangerous drugs, they would limit access to sugar.

A. The FDA has asked manufacturers to limit the amount of loperamide (Imodium) sold in packages to eight pills, enough for about two days of diarrhea control. You may wish to let the agency know what you think about its plan by emailing Commissioner Scott Gottlieb, M.D. at: CommissionerFDA@fda.hhs.gov.