Not Medical Advice:
There are no legal antibiotics sold OTC in the U.S., Canada, New Zealand, Australia, and most European countries; a prescription is always required to legally purchase them. There's a medically sound reason for this:
Bacteria (the only thing for which antibiotics are effective; viruses are not killed by antibiotics) can grew immune to antibiotics over time, and through overuse. Additionally, certain antibiotics are needed to treat certain bacterial illnesses, so blindly taking a random medication may not only fail to help, it can provide a golden opportunity for other bacteria to increase their resistance.
Natural health expert Dr. Oz recommends the following herbal antibiotic alternatives: Goldenseal (Hydrastis), Oregon Grape (Berberis aquifolium), Andrographis paniculata, and Manuka honey.
Always consult a doctor to see if an antibiotic is required for any illness, they can determine which, if any, are the proper medications to take.