This medication does not become dangerous, once expired, but it can lose efficacy. Thus, I feel it should not be taken, as doing so creates the risk of your developing antibiotic resistant bacteria. Given that possibility, my opinion is that it would be best to see your doctor for a new prescription.

On the contrary however, according to Harvard University’s Medical Center, “Most of what is known about drug expiration dates comes from a study conducted by the Food and Drug Administration at the request of the military. With a large and expensive stockpile of drugs, the military faced tossing out and replacing its drugs every few years. What they found from their study is that 90% of more than 100 drugs, both prescription and over-the-counter, were perfectly good to use even 15 years after the expiration date. So, the expiration date doesn't really indicate a point at which the medication is no longer effective or has become unsafe to use. While it's true that the effectiveness of a drug may decrease over time, much of the original potency still remains even a decade after the expiration date.”

Ref: health.harvard.edu/staying-healthy/drug-expiration-dates-do-they-mean-anything

Hopefully this info can help you make an informed decision when it comes to your medication.