Homosildenafil Explained

Homosildenafil (also known as methyl-sildenafil) is a synthetic drug which acts as a phosphodiesterase inhibitor.^[1] It is an analog of sildenafil and vardenafil. Homosildenafil was first identified as an adulterant in sex enhancement products in 2003 and was more recently detected in dietary supplements.^{[2] [3] [4] [5]}

Homosildenafil has 35% the PDE5 inhibition activity of sildenafil itself with similar selectivity.^[1]

Sildenafil is mainly metabolized by the microsomal isozymes CYP3A4 with secondary metabolism by CYP2C9. The major active metabolite is N-desmethylsildenafil. The plasma level of the equivalent homosildenafil metabolite reaches 40% of sildenafil's bioavailability. The N-desmethyl metabolite is further metabolized, with a half-life of 4 hours.^{[6] [7] [8] [9]}

See also

• Aildenafil
• Nitrosoprodenafil
• Sulfoaildenafil

Notes and References

1. Corbin JD, Beasley A, Blount MA, Francis SH . Vardenafil: structural basis for higher potency over sildenafil in inhibiting cGMP-specific phosphodiesterase-5 (PDE5) . Neurochemistry International . 45 . 6 . 859–63 . November 2004 . 15312980 . 10.1016/j.neuint.2004.03.016 . 25178860 .
2. Shin MH, Hong MK, Kim WS, Lee YJ, Jeoung YC . Identification of a new analogue of sildenafil added illegally to a functional food marketed for penile erectile dysfunction . Food Additives and Contaminants . 20 . 9 . 793–6 . September 2003 . 13129773 . 10.1080/0265203031000121455 . 30941705 .
3. Gryniewicz CM, Reepmeyer JC, Kauffman JF, Buhse LF . Detection of undeclared erectile dysfunction drugs and analogues in dietary supplements by ion mobility spectrometry . Journal of Pharmaceutical and Biomedical Analysis . 49 . 3 . 601–6 . April 2009 . 19150190 . 10.1016/j.jpba.2008.12.002 .
4. Web site: Advisory - "Forta for Men" sex enhancement product recalled; contains undeclared drug . PR Newswire . 2014 . 28 April 2015.
5. Zou P, Oh SS, Hou P, Low MY, Koh HL . Simultaneous determination of synthetic phosphodiesterase-5 inhibitors found in a dietary supplement and pre-mixed bulk powders for dietary supplements using high-performance liquid chromatography with diode array detection and liquid chromatography-electrospray ionization tandem mass spectrometry . Journal of Chromatography A . 1104 . 1–2 . 113–22 . February 2006 . 16364350 . 10.1016/j.chroma.2005.11.103 .
6. WO . 2001080860 . Daily treatment for erectile dysfunction using a pde5 inhibitor . 1 November 2001 . De Tejada IS, Ferguson KM, Whitaker JS . Lilly ICOS LLC . . .
7. US . 20090074796 . Pde5 inhibitor compositions and methods for immunotherapy . ohns Hopkins University . 19 March 2009 . Borrello IM, Serafini P, Noonan KA, Bronte V . . .
8. US . 8497370 . Processes for preparing amine salts of sildenafil-analogues and use thereof . Chen IJ . 30 July 2013 . Kaohsiung Medical University . . .
9. CN . 101555512 . Preparation method for monoclonal antibody specifically binding vardenafil and analog thereof . 30 July 2013 . Yang X, Guo J, Huang Z . Kaohsiung Medical University . . .