[Reading Science] Should You Throw Away Household Medicines After One Year?

The expiration date of a pill that has been opened and exposed to air is one year. Medications past their expiration date are likely to have reduced efficacy and may not be effective.
[Photo by YouTube screen capture]

[Asia Economy Reporter Kim Jong-hwa] Nowadays, every household is prepared with emergency medicines. Most of these are common painkillers like headache or cold medicine, and ointments applied to the skin. Sometimes, when a headache occurs and you try to take the medicine, you hesitate.

This is because the medicine was purchased a long time ago. Even after checking the expiration date, there are medicines that are 2 to 3 years past it. You are unsure whether it is safe to take the medicine or if you should avoid it. What should you do?

The fact that expiration dates are indicated on household medicines suggests that there is a limited period during which it is safe to consume them. Is it okay to take medicine slightly past the expiration date, like with general food products? Unlike regular food, medicines do not spoil or rot easily, which makes it more confusing. Regardless of whether problems arise, do these medicines still have efficacy?

First, you need to understand the criteria for determining the expiration date of medicines. The main criteria for setting the expiration date are the 'amount of active ingredients' and the 'concentration of toxic substances.' From the moment a medicine is manufactured at the factory, the concentration of active ingredients begins to gradually decrease.

For a medicine to function properly, the concentration of active ingredients must be maintained above a certain level. The expiration date is set at the point when this concentration falls below the effective level, causing the medicine to lose its intended effect. Especially, the rate at which the concentration of active ingredients decreases accelerates when the medicine is exposed to oxygen after opening.

Therefore, medicines past their expiration date cannot provide the expected efficacy. If the medicine has been opened and exposed to oxygen, it is wise to discard it once the expiration date has passed.

The concentration of toxic substances can also increase due to oxidation. If harmful components are present in trace amounts, they do not significantly affect efficacy, but if they accumulate over a long period, they may negatively impact the human body. Thus, the expiration date is determined by predicting the period during which toxic substances formed inside the medicine will not harm the body.

For solid tablets, the expiration date varies depending on individual packaging, but generally, it is about one year after opening. For tablets stored in bulk in plastic containers without individual packaging, the expiration date is one year from the date of opening.

Tablets prescribed at a hospital and dispensed at a pharmacy have already been exposed to air during the dispensing process, so they should be consumed within two months. These tablets should be stored in a cool place away from direct sunlight and at room temperature with minimal temperature fluctuations before consumption.

Powdered medicines are mostly crushed during the dispensing process. They are also exposed to air and are more vulnerable to moisture, so their expiration date is shorter than tablets. They should be consumed within one month.

The shelf life of tube-type ointments is 6 months after opening. After use, it is recommended to clean the tip of the tube thoroughly before storing.
[Photo by YouTube screen capture]

Liquid syrups should be consumed within one month from the time of opening. When pouring into single-dose containers, exposure to air increases, so they should be consumed within 2 to 3 weeks. If stored for a long time and consumed again, the syrup should be shaken well to mix any settled ingredients before use.

Eye drops such as artificial tears should be used within one month after opening. Since they often come into contact with the eyes, bacteria can easily grow, so if the color changes or other abnormalities occur before one month, they should be discarded. Also, single-use eye drops do not contain preservatives, so once opened, they should not be used beyond one day.

Ointments in tube form can have a very long expiration date if unopened, but once opened, the expiration date is about six months. Since ointments often come into contact with hands or affected areas during application, bacteria can grow on the tube tip, so the tip should be cleaned thoroughly after use.

There is one important rule to follow here. Expired medicines should not be thrown into regular trash bins. Since medicines are chemically synthesized substances, they are difficult to decompose naturally. Disposing of them improperly can cause serious environmental pollution. It is advisable to dispose of them in medicine collection boxes available at pharmacies or public health centers.

Taking expired painkillers without regard to the expiration date can actually be harmful. When stocking household medicines, it is best to keep them unopened, and if opened, strictly adhere to the expiration date.