Questions about Pain Relievers, Sleep Aids, Supplements

In this issue of HealthLink, Dr. Julie L. Mitchell briefly answers a variety of miscellaneous questions.

Question 1: After an expiration date on a medication, how long can you actually keep it? What if it's unopened?

Dr. Mitchell answers:
Generally, expiration dates have been set by pharmaceutical companies, based on their internal tests of the longest period of time that a medication is known to be effective. Based on other studies, medications probably continue to be effective at least one to two years after the expiration date, and maybe as long as 10 to 15 years later. Medications do retain their effectiveness longer if they are kept unopened or unexposed to humid air.

The only report of harm coming from the ingestion of an expired medication was with tetracycline many years ago. So, it's probably safe to take an expired medication, but not if it's a prescription medication that has expired.

Question 2: Is it safe to use the sleep-aid products that are sold without a prescription?

Dr. Mitchell answers:
Almost all the over-the-counter sleep-aid products contain diphenhydramine, also known as Benadryl. They are generally safe, but because they induce sleep, they should be used with caution before driving or operating heavy machinery and they should not be taken with alcohol. They interact with other medications, so if you have other prescriptions, you should check with your doctor or pharmacist.

Question 3: My dentist told me to get an "over-the-counter" brand-name pain reliever for a toothache. But when I compared the store brand to the brand-name, the price was better and all the ingredients and the dose were exactly the same. My daughter says I should have gotten the brand name.

Does it really make any difference?

Dr. Mitchell answers:
No. Generic medications, whether prescription or non-prescription, must pass the same safety and efficacy standards issued by the FDA. By law, the generic product must be the same dose and deliver the same amount of active ingredient in the same amount of time as the brand-name product - this is called "bioequivalence."

In a recent study comparing more than 270 medications, the average difference in bioequivalence between generic and brand-names was 3.5%, about the same difference between batches of brand-name products.

Generic products are cheaper because manufacturers of brand-name medications pass on their cost of research, development, marketing and promotion.

Once a medication is off-patent - or on the market about 17 years - a competing pharmaceutical company can copy the medication with comparatively little effort.

Brand-name products do differ from generics in pill shape, color, taste and inactive ingredients. But the active ingredient, the important piece, is the same.

Question 4: I've never been able to take multivitamins because they are so big! Could I take a children's chewable instead? How many would I take?

Dr. Mitchell answers:
Your letter begs a larger question: Who needs to take a multivitamin? On first consideration, vitamins and minerals are essential to normal body functioning, and one would prefer to err on too much rather than not enough. However, we are learning that some vitamins and minerals can cause harm in excess. For instance, I don't recommend iron to men and postmenopausal women, I don't recommend high doses of vitamin A to people with osteoporosis, and I don't recommend high doses of vitamin E to anyone, especially women with heart disease.

On the other hand, for some groups, vitamin and mineral deficiencies are not uncommon: women of reproductive age may not be getting enough folic acid, postmenopausal women may not be getting enough calcium and vitamin D, and people with malabsorption (inability to absorb nutrients from the intestines) may be deficient in a number of vitamins and minerals.

Your best bet is to make sure you have lots of fruits and vegetables in your diet. If you have an absorption problem or a history of stomach surgery, talk to your doctor about your vitamin and mineral needs.

Otherwise, a single children's multivitamin is not a bad idea. The children's products, unlike the adult products, rarely contain more than 100% of the recommended daily allowance (RDA), and for many vitamins and minerals, the RDA is the same for adults and children older than 4. And, if you look around, you'll find chewable products made for adults.

Question 5: I am taking ground flaxseed and 1,000 mg of fish oil softgels. With all the press about toxins in fish, are they safe to take? I am trying to lower my cholesterol and would like to do this without taking a medicine.

Dr. Mitchell answers:
Flax seed and fish oil may indeed be helpful for people with cholesterol problems. But flax seed and fish oil tablets, considered "nutritional supplements," aren't checked by the Food and Drug Administration for safety nor to ensure that what is in the tablet is truly what is on the label. When buying any supplement, I recommend using a reputable big-name company, or at least a product with an address on the label. You can be reassured by the absence of any reports of toxicity with fish oil supplements.

Julie L. Mitchell, MD, MS, is an Assistant Professor of Medicine at the Medical College of Wisconsin. She practices internal medicine at the Froedtert & Medical College General Internal Medicine Clinic - East. Her column appears in the Milwaukee Journal-Sentinel.