Good reference: The Racing and Medication Testing Consortium
http://www.rmtcnet.com/content_modelrules.aspNote that it\'s far more of a performance-altering threat to give a horse caffeine, than anabolic steroids.
Class 1: Stimulant and depressant drugs that have the highest potential to affect performance and that have no generally accepted medical use in the racing horse.
Examples: morphine, heroin, cocaine, cobratoxin
Class 2: Drugs that have a high potential to affect performance, but less of a potential than Class 1. These drugs are 1) not generally accepted as therapeutic agents in racing horses, or 2) they are therapeutic agents that have a high potential for abuse.
Examples: barbiturates, valium, caffeine, codeine, mepivacaine/lidocaine
Class 3: Drugs that may or may not have generally accepted medical use in the racing horse, but the pharmacology of which suggests less potential to affect performance than drugs in Class 2.
Examples: Acepromazine (tranquilizer), boldenone (Equipoise, an anabolic steroid), clenbuterol, testosterone, stanozolol
Class 4: This class includes therapeutic medications that would be expected to have less potential to affect performance than those in Class 3.
Examples: Tylenol, Zyrtec, cortisone & dexamethasone & prednisone (corticosteroids), isoxsuprine, ketoprofen, bute (phenylbutazone)
Class 5: This class includes those therapeutic medications for which concentration limits have been established by the racing jurisdictions as well as certain miscellaneous agents such as DMSO and other medications as determined by the regulatory bodies.
Examples: Tagamet, Prilosec, Zantac