Larium is a brand name for a medication that contains the active ingredient mefloquine hydrochloride. This drug is typically prescribed to prevent and treat malaria in certain parts of the world. A few synonyms for Larium include mefloquine, Mefliam, mefex, Meflaren, and mefloc. These synonyms are often used to refer to the same drug, but may vary depending on the brand and manufacturer. It's important to note that while these drugs may have different names, they all contain mefloquine and should be used with caution and under medical supervision due to potential side effects.