Which drug is correctly matched with its indication?

Phazyme is accurately matched with its indication as an antiflatulent. This drug contains simethicone, which works by reducing surface tension in gas bubbles, allowing them to combine into larger bubbles that can be eliminated more easily from the gastrointestinal tract. This makes it effective for alleviating symptoms associated with excessive gas, such as bloating and discomfort.

In contrast, the other drugs listed have indications that do not correspond with their specified uses. Didrex is primarily used for weight management and is not classified as an antiemetic. Tigan, which contains the active ingredient trimethobenzamide, is indeed used as an antiemetic but is wrongly categorized as an antiflatulent. Nupercainal, on the other hand, is utilized for its topical analgesic properties and is not an antidiarrheal medication. Thus, Phazyme stands out as the only drug that is correctly matched with its indicated use.