Interest of hair tests and supplement tests to discriminate a tail end of a doping regimen from a supplement contamination in case of challenging an anti-doping rule violation. VII. Case example with clomiphene.

Clomiphene or clomifene is a selective estrogen receptor modulator (SERM) used in therapeutic to enhance the fertility of women. As the drug can influence testosterone circulating concentrations, clomiphene is prohibited at all times under the world anti-doping agency prohibited list in the class S4.2 (hormones and metabolic modulators). Clomiphene can also be administered to animals, particularly hens, due to its fertility-enhancing effect. As a consequence, there is a potential risk of contamination for athletes eating egg products which has already been noticed by sport authorities. The authors report the case of a male athlete who returned an adverse analytical finding for clomiphene with very low concentrations in urine (estimated to be 0.15 and 0.01 ng/mL for clomiphene and 4-OH-clomiphene, respectively). As the athlete challenged the anti-doping rule violation, a hair specimen (black in colour and 6.5 cm in length) was collected about 14 weeks after the urine collection and tested for clomiphene by liquid chromatography coupled to tandem mass spectrometry using a previously described method. Clomiphene was identified at 185, 170 and 125 pg/mg in 3 × 2 cm hair segments, demonstrating repetitive exposures to the drug over the last 6 months. The athlete submitted an egg powder (albumin) used for many months to the laboratory, and this product returned positive for clomiphene at 230 ng/g. Given a daily intake of 20 g, the subject was exposed to 4.6 μg of clomiphene per day that was found consistent to produce the positive signal in urine, in relation with a very long elimination half-life.