Synthetic phosphodiesterase-5-inhibitors use/abuse and interest of hair testing: reporting of a rape case

If classic phosphodiesterase-5 (PDE-5) inhibitors are well known, new synthetic PDE-5 analogues are of more recent introduction. Some of them have already been tested in dietary supplements. We describe here a rape case following the consumption of pills bought on the Internet and containing new synthetic PDE-5 inhibitors. The assailant declared that he lost control after ingesting these pills for the first time. Analyses of conventional matrices (blood, urine) don't allow us to highlight the intake of any substances in relation to this offence due to late sampling (5 days after the offence). Therefore, we have developed an analytical approach to test for PDE-5 inhibitors in hair including the two new synthetic PDE-5 inhibitors analogues - thiosildenafil and hydroxythiohomosildenafil - previously identified in the pills. This new method was validated and applied to the hair samples of the victim and the suspect. Analyses were conducted using a liquid/liquid extraction followed by liquid chromatography coupled with a mass spectrometer in multiple reaction monitoring mode detection. The 2-centimetre proximal hair section of the suspect revealed the presence of thiosildenafil (48 pg/mg), hydroxythiohomosildenafil (24 pg/mg), and sildenafil (7.5 pg/mg). To our knowledge, it is the first time that these two new synthetic PDE-5 inhibitors were detected in biological samples and especially in hair. Complementary investigations showed that a single pill taken by a volunteer provided similar levels in thiosildenafil (35 pg/mg), hydroxythiohomosildenafil (17 pg/mg), and sildenafil (8 pg/mg) to those found in the previous case described here. Copyright (c) 2014 John Wiley & Sons, Ltd.