Cephalexin, often known by the brand name Keflex, is a commonly prescribed cephalosporin antibiotic used to treat various bacterial infections, including those of the skin, ears, and respiratory tract. Understanding the shelf life of this medication is important for ensuring its effectiveness and promoting patient safety. The expiration timeline differs significantly depending on the medication’s form, specifically whether it is a dry tablet or a liquid suspension. Knowing these distinct timelines is necessary for managing your prescription medication safely.
Standard Expiration for Tablets and Capsules
Cephalexin in its dry, solid form (capsules or tablets) is subject to the expiration date printed on the manufacturer’s packaging. This date represents the final point at which the manufacturer guarantees the drug’s full potency and safety when stored correctly. The typical shelf life for an unopened bottle of cephalexin tablets can range from one to five years from the date of manufacture.
The Food and Drug Administration (FDA) requires manufacturers to determine this date through rigorous stability testing of the drug’s chemical composition. After this printed date has passed, there is no guarantee that the medication retains its full active ingredient strength. For solid cephalexin, the primary concern is the gradual loss of therapeutic strength, which may render it ineffective for treating an infection.
The Shortened Shelf Life of Liquid Suspension
The expiration timeline for cephalexin oral suspension is much shorter and begins the moment the medication is prepared. This liquid form is commonly used for children or those who have difficulty swallowing pills. It is supplied to the pharmacy as a dry powder, which a pharmacist must reconstitute by adding water. This reconstitution starts the rapid degradation process of the antibiotic component.
Once mixed, the stability of the cephalexin suspension decreases significantly because the drug is no longer in a dry state. The established shelf life for the liquid suspension is typically limited to 14 days when stored under refrigeration. In some formulations, this period may be only 10 days, so checking the specific label instructions is necessary. The suspension must be discarded after this limited period, even if the patient has not finished the full course of treatment.
Proper Storage to Ensure Drug Stability
The expiration dates for both tablets and liquid are only valid if the medication is stored under the proper environmental conditions. Cephalexin tablets and capsules should be kept at a controlled room temperature, typically between 59 and 86 degrees Fahrenheit (15 and 30 degrees Celsius). The primary threats to drug stability are heat, humidity, and direct sunlight, which can prematurely break down the active compound.
Keeping cephalexin in a consistently cool, dry location, such as a dresser drawer or kitchen cabinet, is recommended. The bathroom medicine cabinet should be avoided, as steam and temperature fluctuations can introduce moisture that degrades the pills. Conversely, the liquid suspension requires refrigeration after mixing to slow the chemical breakdown process.
Safety Risks and Disposal of Expired Cephalexin
Using expired antibiotics carries safety risks that go beyond simply having an ineffective medication. The loss of potency means the drug may not kill all the targeted bacteria, potentially leading to treatment failure and a worsening of the infection. Exposing bacteria to a sub-therapeutic dose also contributes to the development of antibiotic resistance.
Due to these risks, it is important to dispose of expired or unused cephalexin safely. The preferred disposal method is to take the medication to a local drug take-back program or event, which safely incinerates the drugs. If a take-back option is not readily available, the medication can be mixed with an unpalatable substance. This mixture should be sealed in a plastic bag and then thrown in the household trash.