Racing Commissioners International on Tuesday gave its final approval to a list of recommended regulations covering 24 drugs that will be allowed to be administered to racehorses for therapeutic purposes, capping a two-year effort to set the stage for the potential adoption of uniform rules on the substances. The RCI, which is an umbrella group for state racing commissions, has been working with various industry groups to develop the regulations, in the hopes of uniting all 38 parimutuel racing jurisdictions in the United States under one set of rules on therapeutic drugs. The rules will still need to be adopted by individual racing commissions to go into effect. Eight states in the mid-Atlantic, including New York and Maryland, have already pledged to adopt the rules by the end of the year. The RCI has been spearheading the effort to develop the rules while working with a number of other industry organizations, including the Racing Medication and Testing Consortium and the National Horsemen's Benevolent and Protective Association. Several horsemen's groups, however, have indicated that they would like more time to study the regulations before pledging to support them, which could complicate adoption in certain states. In a release, the RCI acknowledged that horsemen still have concerns about environmental contamination, which refers to certain prohibited drugs, such as scopolamine, caffeine, or cocaine, showing up in postrace tests as the result of accidental ingestion. The RCI said that the organization planned to discuss the concerns with horsemen at its conference on April 23 in New Orleans. The  RCI also said that it will begin to hold discussions at the conference on revising penalty guidelines for prohibited drugs, the second phase of the plan to unify rules across racing jurisdictions. Under the regulations, specific concentrations of the 24 drugs on the list will be allowed to appear in postrace samples at levels that are not considered to be pharmacologically significant, or unable to affect the horse's performance on race day. The exception is the anti-bleeding medication furosemide, which will be allowed to be administered up to four hours before a race. Furosemide, commonly known as Lasix, is currently legal to be administered in all U.S. states on race day. Seventeen of the 24 drugs include commonly used painkillers, anti-inflammatories, and treatments for lung and gastrointestinal ailments. The other seven include more powerful drugs that are used to treat specific injuries, and penalties for an overage of those drugs will be more severe than for the other 17 drugs. All other drugs will be prohibited from appearing in post-race samples at any concentration.