When you receive your antibiotics you will see a ‘use by’ date printed on the prescription label. Most states require pharmacists to print a ‘use by’ date one year from the date the prescription was filled. Don’t confuse this ‘use by’ date with a true expiration date. This one-year date is how long until the PRESCRIPTION expires. The actual expiration of the medication is another matter. In the case of antibiotics, the subject has undergone extensive study.
Since 1979 in the United States all drug manufacturers are required to place an expiration date on their products. The expiration date printed by the manufacturer represents the date by which full potency and safety of the drug can be guaranteed. However, most drug companies don’t have the motivation to study their product for years and years to demonstrate how effective or safe the medication may be after 5, 10, 20, or more years.
Fortunately, there is an on-going and extensive study undertaken by the FDA on behalf of the United States Department of Defense. The so-called ‘Shelf Life Extension Program’ (SLEP) was commissioned to reduce medication costs for the military. The military maintains large stockpiles of supplies including medications and was having to rotate their stock regularly due to published expiration dates from the drug manufacturers. This constant need for stock rotation was expensive and efforts were made to study the potency and safety of medication beyond its printed expiration. The scientists in the SLEP study found that the vast majority of the drugs studied (88% representing 122 different drugs) maintained their potency and safety beyond the published expiration date by more than a year, with the average extension being 5.5 years, and a maximum extension of 23 years!
The most stable drugs are those in solid form such as tablets and capsules. Solutions or liquids lose their potency relatively quickly after their expiration dates.
An important caveat, certain medications have a narrow therapeutic index meaning that their safe and effective dose must be exact and kept within certain narrow parameters. Decreases or increases beyond these parameters can result in serious consequences. These types of drugs should not be used beyond their expiration date. An example of such drugs would be vancomycin and monoclonal antibodies.
The antibiotics included in the JASE Medical Emergency Antibiotic Kits are among those studied and shown to be safe and effective for at least 2 years beyond their published manufacturer expiration dates and in some cases for a lot longer. However, neither JASE Medical nor its partner pharmacies or drug manufacturers are included as participants of the FDA’s Shelf Life Extension Program and we therefore officially recommend and follow the manufacturer’s published expiration dates.
Check out these interesting and useful links from official sources:
FDA – Expiration Dating Extension
Journal of the American Medical Association (JAMA) – Drugs Past Their Expiration Date