I noticed that at the pharmacy they always put one year as the expiration date for your medicine. But if you get a medicine in an original container, it has a different date. Is there a law that says they have to put the correct expiration date?

Federal regulations require prescription drug packaging to bear expiration dates “determined by appropriate stability testing” and say that “expiration dates shall be related to any storage conditions stated on the labeling.”

Louisiana regulations require expiration dates on prepackaged drugs — medicine prepared in unit-of-use containers in advance of prescription dispensing — and they require “beyond-use dates” on compounded medication.

Expiration dates indicate when a drug will lose its stability and potency. The beyond-use date — what the reader may be referring to — is the cut-off for patient use and is often preceded by the words “discard after” or “do not use after.”

State regulations say expiration dates must conform to guidelines set by the United States Pharmacopeia, the federally recognized authority on drug standards. The USP’s General Notices and Requirements note that expiration dates vary by drug.

“The monographs for some preparations state how the expiration date that shall appear on the label shall be determined,” reads Section 10.40.100.

“In the absence of a specific requirement in the individual monograph for a drug product or nutritional supplement, the label shall bear an expiration date assigned for the particular formulation and package of the article.”

The USP guidelines say a pharmacist should set a beyond-use date on a noncompounded product after considering the nature of the drug, along with the medicine’s packaging style and storage requirements. But the rules set an upper limit on the dates.

For drugs in multiple-use containers like prescription vials, the guidelines say, the beyond-use date can’t be later than the manufacturer-supplied expiration date or one year from the drug-dispensing date, whichever comes earlier.

For solid and liquid medicines repackaged in unit-dose or single-unit containers, the beyond-use date should be one year from the repackaging date or the manufacturer-supplied expiration date, whichever comes earlier.

Under state regulations, beyond-use dates on compounded drugs can’t exceed 180 days, “unless documentation on file supports a longer beyond use date.”

Additionally, Louisiana’s regulations limit how long a prescription remains valid.

“A prescription for a drug other than a controlled dangerous substance shall expire one year after the date written. … ,” the regulations read.

“A prescription for a controlled dangerous substance listed in Schedule II, III, IV, or V shall expire six months after the date written.”

Online: www.pharmacy.la.gov; www.usp.org.

The Informer answers questions from readers each Sunday, Monday and Wednesday. It is researched and written by Andrew Perzo, an American Press staff writer. To ask a question, call 494-4098, press 5 and leave voice mail, or email informer@americanpress.com

(mgnonline.com)