Homosildenafil

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

Clinical data
ATC code	None
Identifiers
IUPAC name 5-[2-Ethoxy-5-(4-ethylpiperazin-1-yl)sulfonylphenyl]-1-methyl-3-propyl-4H-pyrazolo[4,3-d]pyrimidin-7-one
CAS Number	642928-07-2
PubChem CID	24756844
ChemSpider	22547032
UNII	0Z3JH0S0QK
CompTox Dashboard (EPA)	DTXSID10214510
Chemical and physical data
Formula	C23H32N6O4S
Molar mass	488.61 g·mol−1
3D model (JSmol)	Interactive image
SMILES CCCC1=NN(C)C2=C1N=C(NC2=O)C1=CC(=CC=C1OCC)S(=O)(=O)N1CCN(CC)CC1
InChI InChI=1S/C23H32N6O4S/c1-5-8-18-20-21(27(4)26-18)23(30)25-22(24-20)17-15-16(9-10-19(17)33-7-3)34(31,32)29-13-11-28(6-2)12-14-29/h9-10,15H,5-8,11-14H2,1-4H3,(H,24,25,30) Key:MJEXYQIZUOHDGY-UHFFFAOYSA-N

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
• Hydroxythiohomosildenafil