A new drug that creates the effects of a sedative is being smuggled from Mexico and into the hands of U.S. teen-agers, police and school officials said. The sedative's clinical name is Rohyponl and it is not legally for sale in this country, according to the Federal Drug Administration. Popularly known as Roche, the drug reportedly is being purchased over the counter in Mexicali, Mexico, although it is supposed to be sold with a doctor's prescription there. The drug reportedly creates an effect similar to Valium. Four Calexico students are facing expulsion after being caught dealing the sedatives on campus.