Is It Okay To Take Expired Drugs?

One of the most common questions any pharmacist has to answer is: is it okay to take expired drugs. It’s also one of the hardest questions, with a long answer, because the real answer is “I don’t know� and nobody accepts that even if it is the truth.

It’s important to understand what “:expired� means. It’s not an absolute state, like red light green light – it’s more of a best guess at an estimate. When you take a tablet, the weight of active ingredient isn’t absolute. The label may say “100 milligrams� but it’s actually going to be within a range, something like 90 - 110 milligrams. The exact range will vary from drug to drug, and there are other standards for uniformity, but the thing to keep in mind is that there is a range, and a drug is considered expired when, based on best estimates, it’s at the bottom of its permissible range. Drugs don’t suddenly disappear, so that they’re good on Monday and bad on Tuesday, like a dated supermarket discount. Drugs will normally degrade slowly. That means a drug that has just reached its expiration date is likely to be perfectly good. According to a report in The Wall Street Journal, of March 29,2000, the United States Department of Defense found that it had $1 billion or more of drugs on hand. In order to minimize waste, the military had the United States Food & Drug Administration analyze the drugs. They found that 90% of them were perfectly good even 15 years after they were supposed to have expired. In a published study, the Department of Pharmaceutics of the University of Texas at Austin reported that liquid preparations of metronidazole, an antiinfective agent, which had a labeled expiration date of April 1986, were still had 99.3% or labeled potency when they were assayed in January 1993. According to an article on the web site Medscape.com, Bayer Aspirin is labeled with a 2 to 3 year expiration date, but their own testing shows that the aspirin tablets are still good after 4 years, and they’ve never tested the tablets for more than 4 years.

But – and there’s always a “but� – there are lots of questions that have to be answered before assuming it’s safe to take drugs beyond their expiration date. The drugs the Department of Defense analyzed were properly stored at controlled temperatures. Drugs are likely to degrade more rapidly if they’re subjected to heat, humidity, or direct sunlight. When the Ohio State University College of Pharmacy studied the stability of a suspension of amiodarone, a heart drug, they found it was stable for 90 days in a refrigerator, but only 42 days at room temperature – and neither of these periods come anywhere near 15 years. A Polish study of the stability of cefuroxime, an antibiotic, found that the drug was stable for 2 years when properly stored, but only 6 months when subject to heat and humidity. While aspirin tablets may be stable for as long as 4 years, aspirin breaks up quickly in water. A bottle of aspirin tablets that may be stable on the shelf of an air-conditioned pharmacy, may not last nearly as long in a bathroom medicine cabinet. If the bathroom mirror fogs up when you take a shower, you have to assume that some of that moisture is also getting into the drugs in the medicine cabinet. If you don’t have air conditioning, summer heat can speed up drug degradation.

While it’s best to discuss use of drugs part their expiration with your physician or pharmacist, there are a couple of simple rules to keep in mind. Most non-prescription drugs meet the criteria for safe use after the expiration date, but many prescription drugs don’t – particularly rule #1.

1) Never take drugs past their expiration date unless you have some way of knowing if they’re working. The Medscape article had an anecdote about acetaminophen (the best known brand name is Tylenol) which still relieved pain 4 years after its expiration date. But with acetaminophen, you can tell if it’s working because if it isn’t, you’ll still feel pain – and since it’s a fairly safe drug, you can take a second dose if you have to (read the dose instructions carefully, and never exceed the maximum daily dose.) If a cough medicine isn’t working, you’ll know, because you’ll keep coughing. But – if an antibiotic isn’t working, you won’t know it, and the infection will get worse. It’s not worth the risk.

2) Don’t take chances with drugs that need precise dosing. Thyroid drugs, heart drugs and blood thinners are in this group. These drugs are too important to take chances with. Besides, these drugs are commonly dosed based on based on laboratory tests, and the price of a test is usually greater than nany money you can save on the drug.

2a) The same rule applies for any drug that may be life-saving. If you’re taking aspirin for a headache, you’ll have a headache a little bit longer. But if you’re taking thr aspirin after a heart attack to prevent another heart attack – it’s not worth the risk. Prednisone, and anti-inflammatory steroid, can be used to treat Poison Oak, but it’s also used to treat some cancers. The drug is the same, but the risks are very different.

3) Be careful with liquids. As a rule, tablets are the most stable dosage form, then capsules (the gelatin shell on a capsule may absorb water) and then liquids.