If you require antibiotics while on a cruise, every major cruise ship is equipped with a medical center staffed by licensed doctors and nurses. These facilities function like an urgent care clinic and maintain an onboard pharmacy stocked with common medications, including various broad-spectrum antibiotics for infections like strep throat, UTIs, or pneumonia. You must first have a consultation with the ship's doctor, who will diagnose the issue and write the prescription. Be aware that medical services on ships are typically not covered by standard land-based health insurance and can be quite expensive; a visit and medication can easily cost several hundred dollars. This is why most regular cruisers strongly recommend having travel insurance, which usually allows you to file a claim for reimbursement after you return home.