The Chemistry of Masking Agents

A quick search of Twitter reveals a number of people asking, "Furosemide? My insert family member here> takes furosemide! How can it be a banned substance?" and "How is furosemide a performance enhancer? It's a diuretic!" and "There are approved substances, why didn't he take one of those?" We can address a few of these questions by taking a closer look at what furosemide and other diuretics do and why they show up in the JDA. In his statement following the suspension, Cano claimed he took a diuretic under the supervision of a licensed doctor in the Dominican Republic as part of treatment for an undisclosed medical condition, and was unaware at the time that the medication was on the banned substances list. The list of prohibited substances is broken into five groups: drugs of abuse, performance enhancing substances, stimulants, DHEA, and diuretics and masking agents. Diuretics and masking agents are grouped together because they serve to hinder the detection of the other four categories of prohibited substances. The primary rationale for including diuretics in the list of prohibited substances is their propensity for interfering with detection of other prohibited substances. Some masking agents interfere with the metabolism of other prohibited substances, thereby changing the metabolite signature of the player's urine or concealing a metabolite of the prohibited substance. The presence of a Diuretic or Masking Agent in a Player's urine specimen shall be treated as a positive test result if the IPA determines that the Player intended to avoid detection of his use of another Prohibited Substance. Even if furosemide is not a performance-enhancing substance, it is on the prohibited substances list.