Expired medications can remain effective and safe for the user

(Reuters Health) – A small study suggests that even medicines that have pbaded the expiry date and have not always been stored under harsh weather conditions can retain their original potency.

This is good news for people working in remote areas of the world where expired medicines are sometimes the only ones available and the other solution is not being able to treat a serious illness, wrote the authors of the study. in the journal Wilderness & Environmental Medicine.

"The expiry date on the drug sachet is the deadline by which a pharmaceutical company will guarantee the drug's contents and its stability once stored under the recommended conditions and in its original packaging," said Dr. Emma. Browne, lead author of the study, British Antarctic Survey Medical Unit in Plymouth, UK.

"This date is not necessarily the time when the drug becomes ineffective or dangerous and, for many drugs, this window may be much longer than the usual expiration date, two or three years," he said. she told Reuters Health by email.

In some parts of the world, doctors are struggling to get drugs more than once a year. It may also be costly for small communities or shipping groups to replace unused drugs "just in case," she added.

"The doctor has to decide whether it is safer to give an old medicine or not to treat a disease and hope that the person is doing better, which is a huge ethical dilemma," she said. "As we push the boundaries of exploration, for example, during missions to Mars, the long-term stability of drugs becomes even more important."

The study team tested the stability of five expired drugs that had been referred from the British Antarctic Survey, which operates five bases and two vessels in the Antarctic region and has medical and dental facilities on the spot. Medications for the Antarctic operation are ordered annually in May and shipped from the UK in September; they arrive at the bases in December after spending several months at sea, the researchers noted.

Fresh drugs sent to Antarctica are transported in the hold of the ship, which is not under temperature control. The ship spends about three weeks in the tropics before being transported to the base at a temperature well below 0 ° C. The drugs tested by the Browne team made this trip a second time, when they were sent back because they had exceeded their expiry date, add the authors.

They tested five types of drugs, all out of date for one to four years, and compared them to fresh samples of the same drugs to determine whether the outdated versions were chemically stable and whether their active ingredient was retained.

The drugs included atropine, which is used to treat certain types of poisoning by a pesticide or nerve agent; nifedipine, a calcium channel blocker that relaxes the heart and blood vessels during high blood pressure and chest pain; flucloxacillin, an antibiotic of the penicillin family; bendroflumethiazide, a diuretic used to treat hypertension; and naproxen, a nonsteroidal anti-inflammatory badgesic (NSAID).

The researchers found that all the drugs tested were stable and, in theory, would have always been effective. The researchers cautioned that their findings were limited by the fact that they did not know the exact temperature exposures that the drugs rendered had suffered.

"Even in Western settings, the true longevity of drugs is a relevant issue," said Browne. "There are huge amounts of drugs that are thrown away because they have reached their expiry date, and that is a cost that is transferred to the public through taxes, fees, and taxes. insurance or other medical bills. "

Expiration dates and stability data would be useful for discussing national antidote stocks for bioterrorism and chemical warfare, said Dr. Patil Armenian of the University of California, San Francisco, Fresno, who has not participated in the study.

The Armenian investigated the shelf life of naloxone, an opioid overdose relief drug, and found that it was less stable on contact with heat. If she were left in a car during the hot summers of Arizona, California or other hot spots, some drugs could break down faster, she noted.

"For everyday use, consumers should continue to adhere to the recommended expiry dates," said Browne. "But this opens the door to further research on how expiry dates should reflect the true longevity of medications kept in real environmental conditions."

SOURCE: bit.ly/2T6gGtg Wilderness & Environmental Medicine, Online February 1, 2019.