Capitalizing on the entrepreneurial spirit of the early post-communism days, Hungarian Imre Somody in 1989 put to use his pharmaceutical experience with drug manufacturer Chinoin and co-opted an idea from the Swiss to develop an ef fervescent vitamin tablet.Today, the Plusssz brand tablet, which makes a bubbly vitamin drink, has a 51% share of Hungary's vitamin market, with 25% of Hungarians using the product daily. And that, said the 38-year-old founder, pre sident and CEO of Pharmavit, "is absolutely unique [for the vitamin market] in Europe."In 1995, a 45% price increase, fueled by increased retail margins and higher value-added taxes, held sales down. But this year, Pharmavit expe cts to double 1995 sales in Eastern Europe to $10 million. And by 1997, sales there should reach $20 million, plus another $10 million a year in home market Hungary.Mr. Somody's consistent marketing strategy and his savvy sale to B ristol-Myers Squibb last year are the key elements of his success.Seven years ago, Pharmavit signed then 14-year-old Olympic Gold medal swimmer Krisztina Egerszegi to a Plusssz endorsement deal. Until then, product tie-ins with ath letes were unheard of in Eastern Europe. But Hungary's sports sweetheart proved perfect for delivering the simple message, "I like it and I need it!" Mr. Somody has never strayed from the original positioning of the product as a readily available, good-tasting health drink. For the past three years, DDB Needham, Budapest, has built on that concept for Plusssz launches in other Eastern European countries. Local sports heroes such as a Romanian gymnast and a Polish judo star are available for endorsements at bargain prices of $50,000 to $100,000 a year.Pharmavit spends some $1.5 million annually on advertising in Poland and in Romania, building brand awareness to about 35% for Plusssz in those markets in only 2 1/2 years. In Hungary, Plusssz's annual ad budget is around $2 million.In 1992 Pharmavit began exporting Plusssz, now available in the Czech and Slovak republics, Poland, Romania, Vietnam, Russia, Ukrain e and other CIS countries. Originally made in only vitamin C and multivitamin versions, the brand has grown to eight products for various age groups. Pharmavit distributes Plusssz mostly in food stores and some pharmacies. But mark eting dollars were too few and distribution outlets too limited when Pharmavit decided to target larger markets like Russia. That's when the pragmatic Mr. Somody turned to Bristol-Myers Squibb.The U.S. pharmaceutical giant bought 9 9% of Pharmavit in late 1995. Now Bristol-Myers Squibb is helping Pharmavit take Plusssz to its niche markets-developing countries in Asia and South America where health awareness has improved but healthcare hasn't. Bristol-Myers S quibb's worldwide distribution system can get Plusssz to market quickly."This is the synergy between the big multinational and our product," said Mr. Somody.