Antibiotics are medications that combat bacterial infections. Their effectiveness relies on chemical stability, which environmental factors can influence. Proper storage is important to ensure they work as intended and for patient safety.
Why Storage Matters
Antibiotic storage directly impacts their potency and stability. These complex chemical compounds are susceptible to degradation when exposed to conditions outside recommended storage parameters. Heat, light, and moisture are primary factors that accelerate this breakdown. Some antibiotic compounds, particularly beta-lactams like amoxicillin, can degrade quickly at higher temperatures. This degradation reduces the active ingredient, making the medication less effective.
Many antibiotics, especially in tablet or capsule form, are stable at room temperature, but others require cooler conditions. Liquid suspensions, often reconstituted from a powder, are particularly sensitive to temperature fluctuations. Refrigeration slows degradation, preserving the antibiotic’s potency for its intended duration. Improper storage can diminish the therapeutic effect, meaning the medication may not effectively treat the infection.
How Long Refrigerated Antibiotics Last
Refrigerated liquid antibiotics, such as amoxicillin or cephalexin suspensions, maintain stability and effectiveness for a limited period once mixed. For many common suspensions, this timeframe is between 7 to 14 days when stored at 2°C and 8°C (36°F and 46°F). After this period, the active ingredients degrade, leading to a loss of potency.
If these medications are left out of the refrigerator for too long, their therapeutic effectiveness will be compromised. While usually not toxic, their ability to treat the infection diminishes significantly. For temporary excursions, such as during transport, a few hours outside of refrigeration might not immediately render the medication ineffective. Some studies suggest that amoxicillin suspensions can remain stable at room temperature for up to 5 to 7 days, though refrigeration is preferred and extends the stability.
Cumulative time out of refrigeration can accelerate degradation. For example, amoxicillin can lose about 25% of its potency when stored at room temperature for 10 days compared to 17% when refrigerated. Return refrigerated antibiotics to the fridge as soon as possible, and adhere to the expiration date provided by the pharmacist. Always consult the specific instructions on the prescription label or ask a pharmacist, as exact stability times vary by medication and formulation.
Disposing of Medication
If antibiotics have been left out of refrigeration for an extended period, have passed their expiration date, or are no longer needed, do not take them. Signs of degradation in liquid antibiotics include changes in color, consistency (grainy or clumpy), or an unusual smell. Taking compromised medication can lead to ineffective treatment and potentially contribute to antibiotic resistance.
Proper disposal of unused or expired medications prevents accidental ingestion, misuse, or environmental contamination. The best method is typically through drug take-back programs. Many pharmacies, including Walgreens and CVS, offer secure kiosks for medication disposal. The Drug Enforcement Administration (DEA) also holds National Prescription Drug Take Back Days annually in April and October.
If a take-back program is not readily available, most medications can be disposed of in household trash. To do this safely, remove the medication from its original container and mix it with an undesirable substance like dirt, used coffee grounds, or cat litter. Place this mixture into a sealed plastic bag or another disposable container. Scratch out all personal information on prescription labels before discarding the container. For disposal uncertainties, consult a pharmacist.