Does expired antibiotics become toxic?

Spider1904: No, the expiration date does not indicate a point when a medication loses potency and is no longer effective or becomes harmful. The expiration date, required by law in the United States, indicate the date the manufacturer guarantees the full potency and safety of the drug. At the time of the medication expiry date, the drug must be at least 90% of the original potency under proper storage conditions. In general, drugs expiration date is 2-5 years from production date.