St. Joseph's Aspirin for Children, once a leader in over-the-counter pain relief for youngsters, is slowly disappearing from medicine cabinets. The manufacture of the chewable orange tablets ended in December 1986 as Shering Plough Corp. of Madison focuses on chewable low-dosage aspirin products for adults concerned about preventing heart disease. Aspirin-free pain relievers and name-brand aspirin products competed with each other until the American Academy of Pediatrics, in a report in 1982, said giving aspirin to children suffering from chicken pox and influenza increased the risk of contracting Reye's syndrome. The illness is fatal in about 20 percent to 30 percent of the cases, and some survivors suffer permanent brain damage. The government in 1986 ordered warning labels on all aspirin bottles about the risk to children and teen-agers of contracting Reye's syndrome. The market ``dropped considerably from 1980 with the Reye's syndrome business,'' said Terry Kelly, a spokesman for Sterling Drug Inc. of New York, which still manufactures Bayer's Aspirin for Children. ``We feel there are certain patients for whom children's aspirin is appropriate,'' Kelly said. St. Joseph's Aspirin for Children, first marketed in 1949, was replaced with aspirin-free tablets called St. Joseph's Aspirin-Free Fever Reducer. Jim Saberton, a consultant with Kline & Co. Inc. in Fairfield, said Wednesday that the children's aspirin market has become relatively small with sales of about $15 million in 1986 compared with sales of about $115 million for the non-aspirin pain reliever acetominophen that same year. ``The risk and work involved in making aspirin is unattractive, especially since there's acetominophen,'' he said. St. Joseph's Aspirin for Children and Bayer Children's Aspirin each had about $5 million in sales in 1986, with the balance of sales taken up by generic brands, he said. He also said Johnson & Johnson's Tylenol products, which use acetominophen, cut heavily into sales of St. Joseph's, which once held 50 percent of the children's pain-reliever market while Bayer had the other half. Lewis Nolan, a Schering Plough spokesman, said, however, that his company disputes the link of aspirin to Reye's syndrome. ``It's been our position that there's been no scientific valid evidence to link aspirin and Reye's syndrome,'' he said. St. Joseph's Low Dose Adult Aspirin was introduced last month, although the company makes no claim in relation to aspirin's effectiveness against heart disease. The low dose aspirin product label advises it not be given to young children, he said. Kelly said his company showed higher sales of Bayer Children's Aspirin during 1987, although he could not say if it was due to Shering Plough leaving the market. ``I think the first increase you saw was ours last year. I cannot analyze why that is,'' he said.