“Expired medications can give rise to toxic compounds”

Most people pay close attention to the expiration dates of foods such as canned goods, meat and milk. We know that eating spoiled food can be harmful and that’s why we watch for the signs that it has gone bad. But what about medications? Are expiration dates so important? If we go to our medicine cabinet, we will surely find old medicines, remnants of an old prescription or the cold we had a few months ago. What do we do with them?

What does the expiration date of medicines indicate?

All medicines have an expiration date. This is established by the Medicines Act. Each undergoes rigorous stability testing to determine how the quality of active ingredients changes over time due to factors such as temperature, humidity and light.

This date, indicated on the packaging by a black hourglass in month/year format (MM/YY or MM/YYYY), indicates the limit up to which the product remains safe, retains its properties of effectiveness and quality, provided that it has been stored in good conditions – in a cool and dry place, away from direct sunlight and, in some cases, even in the refrigerator. Until the indicated date, a medicine can be used with complete peace of mind.

As Eduardo Senante Perdiguer, community pharmacist, explains to us, the expiry date is the “period during which the laboratory guarantees that the medicine will continue to be chemically stable and will be safe for the patient”.

What happens when a medicine is expired

If the date indicated on the package has passed, “in most cases, medications lose their effectiveness over time,” Senante warns, due to changes in the chemical composition. Although these do not occur from one moment to the next, it is true that from the expiration date “the chemical degradation of the active ingredient will be much more gradual and this will make the effect weaker, or even insufficient,” explains Senante.

In most cases, the effects do not go beyond a loss of effectiveness which, as we will see, is not unrelated to certain medications. But it can also happen, although these are more extreme cases, “that the active ingredients degrade and give rise to toxic, irritating compounds or which cause a certain type of reaction. Once this expiry date has passed, there is a real risk of contamination if the medicine has already been opened before. Therefore, the general recommendation is not to use expired medicines”, explains Senante.

With which medications should we be particularly careful?

Generally, liquid solutions, sachets and eye drops degrade more quickly than solid forms. If we take paracetamol as an example, “as it is an analgesic, the reduction of effects may be less relevant, but there are cases where it is extremely important,” explains Senante.

What are these cases? As the specialist explains, there are several types of medications to pay attention to, such as those “that contain hormones, such as thyroid medications, contraceptives, fertilization medications.” in vitroamong other things, because they are very sensitive to heat and humidity. » Antibiotics also require us to be particularly careful, because “they must reach adequate levels in the blood and, if they are expired, we do not know what their concentration will be, and a weakened antibiotic may not only fail, but will contribute to not curing the disease and also to a possible development of bacterial resistance, a very important risk that we must avoid,” explains Senante.

Another group of medicines for which we will have to be attentive to the expiration date are “insulins and other biological medicines, which require very specific and controlled storage conditions. If they expire, they seriously lose their effectiveness”, warns Senante.

We must also be careful “with eye drops and other medications intended for ocular use because it is very easy for them to be contaminated by microorganisms once expired and can cause infections,” specifies the pharmacist. The same goes for “medications for the cardiovascular system: antiarrhythmics, antihypertensives or anticoagulants must be super stable and taking them out of date can be dangerous,” he explains.

Finally, the pharmacist also talks about inhalers, which “contain a propellant gas which causes the active ingredients, once expired, to accelerate their degradation. Faced with an asthma attack, an expired inhaler does not resolve this crisis,” warns the specialist.

Taking these medications with less effect can lead to health complications, so it is always advisable to replace them before the expiration date.

What happens to multidose medications after opening, such as eye drops? Does the validity period change? “Once we open a multidose container, the expiration date is no longer valid,” explains Senante. From this moment begins what is called, according to the specialist, the useful life, which will depend and be influenced by factors such as the risk of contamination, oxidation and accelerated degradation of the active ingredient.

In the case of eye drops, “most last 28 days after opening,” he specifies. Inhalers are also a multidose medication and, “although each has its own period of validity after opening (some can last months, others weeks), it is very important to always review the package leaflet because we cannot include them all under the same conditions of use after opening,” explains Senante.

And the syrups? “Once opened, they usually last about six months, although this depends on the preservative, active ingredient and excipients.” In the case of antibiotic syrups, which have just been prepared at home by the patient himself, “they only last seven to fourteen days once reconstituted. Once the treatment is finished, they must be thrown away”, specifies Senante.

In the case of creams and lotions, what governs is what we call PAO, the acronym in English for Period after opening, i.e. the period after opening, which is usually represented as an open jar with a number and the letter M (month) inside and a number that indicates the time “for which we can keep it open after its first use. It is not an expiration”, specifies Senante.

Tips to prevent medications from expiring

If we do not want our medicine cabinet to become a bottomless warehouse, full of expired medications, it is important to take into account a series of conditions. For Senante, this is the key:

“If a medicine is expired or has been opened for months, if in doubt, it is best not to use it,” concludes Senante.

What do we do with expired medications?

Expired medicines should never be thrown away as they can end up in the environment and some are toxic to aquatic life, such as paracetamol or antibiotics. If we have expired medicines at home, or which we no longer need, even if we accumulate a few empty containers, we must drop them off at the SIGRE Point of any pharmacy.

We can leave expired medications inside the container and with its box and instructions, as well as empty containers such as blisters, tubes or vials. It is not necessary to remove any leftover medication left in the container: they must be thrown away at the SIGRE point with the box and the leaflet. This is necessary because the box makes it easier to identify the medicine it contains and, depending on its type, one treatment or another is applied.