You always have to have your guard up. But I'm not sure how you could prevent this from happening! If the people serving the drinks are drugging them, behind the bar, how can you keep yourself safe?
From Inside Edition:
Mexico is a hugely popular destination for American tourists, as roughly 9 million of them visited the country last year. The State Department has issued a travel warning for Mexico, following allegations that tainted alcohol is being served at various resorts. At Iberostar Playa Paraiso, an all-inclusive luxury resort on the Riveria Maya, the booze flows like water. Jamie and Rick Valeri, tourists from Wisconsin, say they lost consciousness after drinking beer and mojitos at the resort in 2015.