Tadalafil-d3 is intended for use as an internal standard for the quantification of tadalafil by GC- or LC-MS. Tadalafil is a potent inhibitor of phosphodiesterase 5 (PDE5; IC50 = 1.2 nM).1 It is selective for PDE5 over PDE1-4 and 7-10 (IC50s = 9.2-280 μM), however, it does also inhibit PDE11 (IC50 = 11 nM). In vivo, tadalafil (10 mg/kg) decreases production of the proinflammatory cytokines TNF-α, IL-1β, and IL-6 and improves renal function in a rat model of ischemia/reperfusion injury.2 It also reduces development of tobacco smoke-induced emphysema and pulmonary hypertension in mice.3 Formulations containing tadalafil have been used to treat erectile dysfunction, pulmonary arterial hypertension, and lower urinary tract dysfunction.
1.Card, G.L., England, B.P., Suzuki, Y., et al.Structural basis for the activity of drugs that inhibit phosphodiesterasesStructure12(12)2233-2247(2004) 2.Medeiros, V.F., Azevedo, Í.M., Carvalho, M.D., et al.The renoprotective effect of oral tadalafil pretreatment on ischemia/reperfusion injury in ratsActa. Cir. Bras.32(2)90-97(2017) 3.Seimetz, M., Parajuli, N., Pichl, A., et al.Cigarette smoke-induced emphysema and pulmonary hypertension can be prevented by phosphodiesterase 4 and 5 inhibition in micePLoS One10(6)e0129327(2015)