Vardenafil (Levitra) is an oral therapy for the treatment of erectile dysfunction. It is a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5). Penile erection is a hemodynamic process initiated by the relaxation of smooth muscle in the corpus cavernosum and its associated arterioles. During sexual stimulation, nitric oxide is released from nerve endings and endothelial cells in the corpus cavernosum. Nitric oxide activates the enzyme guanylate cyclase resulting in increased synthesis of cyclic guanosine monophosphate (cGMP) in the smooth muscle cells of the corpus cavernosum. The cGMP in turn triggers smooth muscle relaxation, allowing increased blood flow into the penis, resulting in erection. The tissue concentration of cGMP is regulated by both the rates of synthesis and degradation via phosphodiesterases (PDEs). The most abundant PDE in the human corpus cavernosum is the cGMPspecific phosphodiesterase type 5 (PDE5); therefore, the inhibition of PDE5 enhances erectile function by increasing the amount of cGMP.
T-värdet i faropäng avser akut toxicitet. Uppgifterna om fara och risk, med undantag för B, baseras på tidigare miljöinformation på Fass.se. Miljöinformation saknas på fass.se (2018-11-06). Det är frivilligt för tillverkare att lämna uppgifter om miljöpåverkan på fass.se. Underliggande data för B kommer från artikeln Fick J et al. 2010. Below is Hazard and Risk from Fass environmental information Levitra (vardenafil) (downloaded 2011-05-16) Hazard Persistence: "The study was performed according to Council Dir. 92/69/EEC, C.4-E (Closed bottle test).The test substance was incubated in aqueous solutions for 28 days it. Additionally, a reference substance was tested as control. Additional vessels without any test or reference substance were used as blank (control). The biological degradation of the test and reference substances was evaluated by the decrease of dissolved oxygen in the solutions. No degradation of the test substance was observed." Bioaccumulation: Log Pow = 3.2. Acute toxicity: Data available for 1 trophic level for crustaceans (Daphnia magna) 2 800 microg/L. Risk "The risk of the potential environmental impact cannot be evaluated, however some ecotoxicity data are available." The article Fick J et al. 2010 Critical effect concentration (CEC) for vardenafil is 628 ng/L. Log P is set to 2.8.
Fick J, Lindberg RH, Tysklind M, Larsson DG. Predicted critical environmental concentrations for 500 pharmaceuticals. Regul Toxicol Pharmacol. 2010;58:516-23.