While commonly used over the counter medications may be available in port, from the ship's store, or from the ship's doctor, it is highly recommended that you bring any required medications on board with you. The medical pharmacy only has a limited supply of medications and they can be hard to find at port. Let your stateroom steward know and they may be able to help you locate needed medicines.
Pharmacy supplies that may be avaliable onboard may include seasickness pills, aspirin and other over-the-counter products, antibiotics and limited supplies of prescription medications, as well as emergency medications