Dear Daisy Dog
How long do drugs remain effective? Last year, the veterinarian prescribed prednisone for my dog’s allergies, and I would like to use the leftover tablets for this year’s allergies. May I?
The official answer is: It depends on the expiration date on the stock bottle from which your prescription was dispensed. Unfortunately, that information may be hard to find now.
The unofficial answer is: You probably can use the medication, because most tablets and capsules degrade slowly.
The Food and Drug Administration and Department of Defense tested more than 100 drugs and found that 90 percent were safe and effective years after the manufacturer’s expiration date.
Heat, humidity and light degrade drugs, so if you stored your dog’s prednisone in the bathroom medicine cabinet, throw it away.
Similarly, discard it if its color, texture or odor has changed.
If you stored the medication in a cool, dry, dark place and it appears unchanged, it might still be safe and effective.