You add another
small prescription bottle to that too crowded medicine cabinet, the
bottles nudge each other out of place, some tumbling out and down
the sink. A quick date-inventory finds half of them in varying dates
of expiry: a month, 6 months, a year. Tsk, tsk, tsk . . . what a waste!
. . . and you're swiping the "expired" prescription drugs,
over-the-counters, vitamins and supplements to the trash to make room
for the new prescriptions.
What does
the expiration date signify? Have the "expired" medications
really lost potency? Do they really expire on the expiry dates?
"Expired," do they become harmful?
The "expiry date" or "expiration
date" does not indicate a point when a medication loses
potency and is no longer effective or becomes harmful. It is
simply a date "required by law" generally set at two
to three years after the '"manufacture date" of new
medicines, usually embossed or printed on the original packaging.
For prescriptions filled by the pharmacist, it is usually dated
a year after being dispensed from the original container.
Drug companies admit there are no real
data and that since some drugs expire earlier or faster than
others, some manufacturers make a calculated guess at shelf life,
then cut that in half to avoid legal consequences.
Studies have been done to
test the stability of drugs beyond the expiration date. Stored
under reasonable conditions, many drugs retain 90% of their potency
for at least five years after the label's expiration date; sometimes,
longer.
The FDA studied more than 100 drugs.
It found that 90 percent of both prescription and over-the-counter
medicines were perfectly good to use even 15 years (!)
after the expiration date.
The exceptions are insulin, liquid antibiotics
and nitroglycerin.
And loss of potency does not translate
to harmfulness. Other than a contested report associated with
use of degraded tetracycline causing Fanconi's syndrome, there
are virtually no reports of toxicity from outdated drugs. At
most, they lose some potency.
Storing the medications in a cool place,
such as a refrigerator, will help extend potency for many years.
However, most impoverished Third World countries do not have
the luxury of refrigeration or cool storage places, and stability
studies need to be done for drugs in the environ of prolonged
heat and humidity.
Is the expiry date a mere marketing
ploy? A commercial ploy that tags obsolesence to still potent
drugs? Easy math. . . billions of drugs are regularly trashed
and dumped because of expiration dates. Worldwide, the amount
is staggering. Manufacturers claim for "product integrity."
Consumers cry "profit!"
And for sure, the dilemma of expiry
dates will continue to be cause for concern. How long ago did
it "expire?" How much have time, heat and humidity
contributed to a decline in potency? In many impoverished settings
of third world countries, patients don't have much of a choice.
And when an "expired" drug works, it might have done
so through its persisting potency, or through the powers of placebo
or through a dose of tincture of time.
Some physicians
feel comfortable doubling the time of use, from manufacture to
expiration date.
In impoverished areas, where the choice
is to treat wtih "expired" medications or NO treatment,
the choice is a 'no-brainer.'
But if there is a choice, where potency
is further brought to question because of weather and storage
and cost not a problem, there are certain conditions where 100%
absolute certainty of potency is preferable - for heart conditions,
strokes, TIAs, and life-threatening infections. Aspirin potency
may not be as important for the simple ache or headache as it
would be in a TIA, stroke prevention or heart conditions. Antibiotic
potency might not be as critical in the empiric treatment for
suspected sinus infections as they might be for respiratory infections
in the elderly and lung-compromised patients.
So, when the urgency of clinical situation
dictates, or when the conditions of storage are of concern, together
with length of time beyond expiry date - until technology can
gadget up some time-and-cost-effective way of determining drug
potency - for both over-the-counter and prescription pharmaceuticals,
opt for the new bottle or the new prescription.
