PDE5 (IC50 = 0.7 nM); PDE6 (IC50 = 11 nM); PDE1 (IC50 = 180 nM); PDE3 (IC50 >1000 nM); PDE4 (IC50 >1000 nM)

Vardenafil dihydrochloride has an IC50 value of 0.7 nM, which is specifically used to inhibit PDE5's hydrolysis of cGMP[1]. The intracellular cGMP levels in the penis's cavernosum tissue are raised by vardenafil dihydrochloride, which causes the body's sinuses and blood flow to dilate[3].

Rats with cavernous nerve damage show facilitator effects when given vardenafil dihydrochloride (0.03 mg/kg; IV)[4]. Vardenafil dihydrochloride (0.17 mg/kg; iv; once daily; 7 d) reduces the production of iNOS and NF-���B in hepatic tissue and shields the liver against Con A-induced hepatitis[5]. In ZDF hearts, vardenafil dihydrochloride (10 mg/kg; po; once daily; 25 weeks) inhibits both the rise in 3-NT production and the decrease in tissue cGMP levels[6].

In this study, researchers investigated the potency and the selectivity profile of vardenafil on phosphodiesterase (PDEs) enzymes, its ability to modify cGMP metabolism and cause relaxation of penile smooth muscle and its effect on erections in vivo under conditions of exogenous nitric oxide (NO) stimulation. PDE isozymes were extracted and purified from human platelets (PDE5) or bovine sources (PDEs 1, 2, 3, 4 and 6). The inhibition of these PDEs and of human recombinant PDEs by vardenafil was determined. The ability to potentiate NO-mediated relaxation and influence cGMP levels in human corpus cavernosum strips was measured in vitro, and erection-inducing activity was demonstrated in conscious rabbits after oral administration together with intravenous doses of sodium nitroprusside (SNP). The effects of vardenafil were compared with those of the well-recognized PDE5 inhibitor, sildenafil (values for sildenafil in brackets). Vardenafil specifically inhibited the hydrolysis of cGMP by PDE5 with an IC50 of 0.7 nM (6.6 nM). In contrast, the IC50 of vardenafil for PDE1 was 180 nM; for PDE6, 11 nM; for PDE2, PDE3 and PDE4, more than 1000 nM. Relative to PDE5, the ratios of the IC50 for PDE1 were 257 (60), for PDE6 16 (7.4). Vardenafil significantly enhanced the SNP-induced relaxation of human trabecular smooth muscle at 3 nM (10 nM). Vardenafil also significantly potentiated both ACh-induced and transmural electrical stimulation-induced relaxation of trabecular smooth muscle. The minimum concentration of vardenafil that significantly potentiated SNP-induced cGMP accumulation was 3 nM (30 nM)[1].

Animal/Disease Models: Male rat (9weeks old) underwent surgery for laparotomy or bilateral cavernous nerve (CN) crush injury[4]
Doses: 0.03 mg/kg
Route of Administration: intravenous (iv) injection
Experimental Results: Restored normal erectile responses with a combind administration of BAY 60-4552 (0.03, 0.3 mg/kg).

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Animal/Disease Models: Liver injury induced by Con A in male Swiss albino mice (20 ± 2 g)[5]
Doses: 0.17 mg/kg
Route of Administration: intravenous (iv) injection; one time/day, for 7 days; as a pretreatment
Experimental Results: decreased the levels of serum transaminases and alleviated Con A-induced hepatitis.

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Animal/Disease Models: Male 7weeks old Zucker diabetic fatty (ZDF) rats (preserved ejection fraction, HFpEF)[6]
Doses: 10 mg/kg
Route of Administration: po (oral gavage); one time/day, for 25 weeks
Experimental Results: Improved myofilament function in diabetic rat hearts.

Absorption, Distribution and Excretion
Within the recommended dose range, the pharmacokinetic characteristics of vardenafil are dose-proportional. In healthy male volunteers, after an oral administration of 20 mg vardenafil on an empty stomach, peak plasma drug concentrations were reached within 30 minutes to 2 hours (median 60 minutes), and 0.00018% of the drug was detectable in semen 1.5 hours post-administration. The bioavailability of vardenafil is approximately 15%. A high-fat diet can reduce Cmax by 18%–50%; however, AUC or Tmax remained unchanged. Vardenafil is primarily excreted as metabolites in feces and urine. Approximately 91–95% of the orally administered dose is excreted in feces, and 2–6% in urine. The steady-state volume of distribution of vardenafil is 208 L. The systemic clearance of vardenafil is 56 L/h. Protein binding: Very high: 95% bound to plasma proteins; reversible and independent of total drug concentration.
Absorption is rapid; absolute bioavailability is approximately 15%. In healthy volunteers, after an oral administration of 20 mg on an empty stomach, peak plasma concentration is typically reached within 30 minutes to 2 hours (median 60 minutes). A high-fat meal reduces peak plasma concentration (Cmax) by 18% to 50%.
In rabbits, the enhanced erectile function of 0.1 mg/kg vardenafil, induced by nitric oxide (NO), is limited by its pharmacokinetic properties (Tmax = 1 hour; T1/2 = 1.2 hours), although an erectile effect was still observed after 7 hours. In humans, vardenafil is rapidly absorbed (Tmax approximately 40 minutes) and slowly metabolized (T1/2 approximately 4 hours), with an absolute bioavailability of 14.5% (compared to 40% for sildenafil). While a high-fat meal does not affect relative bioavailability, it does delay intestinal absorption. Concomitant use with CYP3A4 inhibitors such as ritonavir can affect hepatic metabolism. M1 is the active metabolite of vardenafil, and its PDE5 inhibitory potency is four times lower than that of the parent compound, accounting for approximately 7% of the total therapeutic efficacy of vardenafil.
Time to peak concentration: 30 minutes to 2 hours (oral, fasting)
For more complete data on the absorption, distribution, and excretion of vardenafil (11 metabolites), please visit the HSDB record page.

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Metabolism/Metabolites
Vardenafil is primarily metabolized in the liver via CYP3A4, but CYP3A5 and CYP2C isoenzymes also participate in its metabolism. The major circulating metabolite, M1 (N-deethylvardenafil), is a partially deethylated product of vardenafil piperazine, and its plasma concentration is approximately 26% of that of the parent compound. M1 has similar phosphodiesterase selectivity to vardenafil, and its in vitro PDE5 inhibitory potency is approximately 28% of that of vardenafil. M1 is primarily metabolized in the liver via CYP3A4, with contributions from CYP3A5 and CYP2C isoenzymes. M1 is the product of partial deethylation of vardenafil-piperazine and is the main circulating metabolite. M1 undergoes further metabolism. The plasma concentration of M1 is approximately 26% of the parent compound and accounts for 7% of the total pharmacological activity. This metabolite exhibits phosphodiesterase selectivity similar to vardenafil, with an in vitro PDE5 inhibitory potency 28% that of vardenafil.

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Biological Half-Life
The terminal half-life of vardenafil and its main metabolite (M1) is 4–5 hours.
Terminal half-life: 4–5 hours

Hepatotoxicity
Although vardenafil is widely used, no clinically significant liver injury cases have been identified, and elevated serum enzymes during treatment are rare. The related PDE5 inhibitors sildenafil and tadalafil have been associated with rare cases of acute liver injury and jaundice. The incubation period ranged from a few days to 3 months, and the injury pattern was typically cholestatic. No autoimmune or immune hypersensitivity features were observed, and all cases were self-limiting without sequelae or acute liver failure. Whether vardenafil can cause similar acute liver injury is unclear. Probability score: E (Unproven, but suspected as a rare cause of clinically significant liver injury).
Effects During Pregnancy and Lactation
◉ Overview of Use During Lactation There is currently no publicly available information regarding the use of vardenafil during lactation. Alternative medications may need to be considered. ◉ Effects on Breastfed Infants As of the revision date, no relevant published information was found.
◉ Effects on lactation and breast milk
As of the revision date, no relevant published information was found.

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Protein binding
Approximately 95% of vardenafil and its major circulating metabolites are bound to plasma proteins. Their protein binding is reversible and independent of the total drug concentration.

[1]. The phosphodiesterase inhibitory selectivity and the in vitro and in vivo potency of the new PDE5 inhibitor vardenafil. Int J Impot Res. 2001;13(5):282-290.

[2]. Vardenafil dihydrochloride. Profiles Drug Subst Excip Relat Methodol. 2014;39:515-544.

[3]. Erectile dysfunction: comparison of efficacy and side effects of the PDE-5 inhibitors sildenafil, vardenafil and tadalafil--review of the literature. Eur J Med Res. 2002 Oct 29. 7(10):435-46.

[4]. Combination of BAY 60-4552 and vardenafil exerts proerectile facilitator effects in rats with cavernous nerve injury: a proof of concept study for the treatment of phosphodiesterase type 5 inhibitor failure. Eur Urol. 2011 Nov. 60(5):1020-6.

[5]. Hepatoprotective role of vardenafil against experimentally induced hepatitis in mice. J Biochem Mol Toxicol. 2017 Mar. 31(3).

[6]. Long-Term PDE-5A Inhibition Improves Myofilament Function in Left and Right Ventricular Cardiomyocytes through Partially Different Mechanisms in Diabetic Rat Hearts. Antioxidants (Basel). 2021 Nov 6. 10(11):1776.

Vardenafil is a sulfonamide compound formed by the condensation of the sulfonic acid group of 4-ethoxy-3-(5-methyl-7-propylimidazo[5,1-f][1,2,4]triazine-4(1H)-keto-2-yl)benzenesulfonic acid with the secondary amino group of 4-ethylpiperazine. It is a vasodilator and an EC 3.1.4. (phosphodiesterase) inhibitor. It belongs to the N-alkylpiperazine, imidazotriazine, and N-sulfonylpiperazine classes. Vardenafil is a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5) and is an oral medication used to treat erectile dysfunction. During sexual stimulation, nerve endings and endothelial cells in the corpora cavernosa of the penis release nitric oxide (NO), activating guanylate cyclase and increasing the synthesis of cGMP in the smooth muscle cells of the corpora cavernosa. PDE5 inhibitors, such as vardenafil, inhibit the degradation of cGMP, thereby increasing blood flow to the penis and ultimately leading to erection. Vardenafil is a more potent PDE5 inhibitor than sildenafil and tadalafil; however, its selectivity for other PDE subtypes is lower than that of tadalafil. The U.S. Food and Drug Administration (FDA) approved vardenafil for the treatment of erectile dysfunction in 2003. Although rare cases of acute liver injury have been reported with other PDE5 inhibitors, such as sildenafil and tadalafil, the use of vardenafil has not been found to be associated with hepatotoxicity. The efficacy of vardenafil as monotherapy for pulmonary hypertension has also been evaluated. Vardenafil is a phosphodiesterase type 5 (PDE5) inhibitor. Its mechanism of action is as a PDE5 inhibitor. Vardenafil is a selective inhibitor of PDE5 and is used to treat erectile dysfunction. Vardenafil is not associated with elevated serum transaminases or clinically significant liver injury. Vardenafil is a benzenesulfonamide derivative and a phosphodiesterase type 5 (PDE5) inhibitor with vasodilatory effects. Vardenafil selectively inhibits PDE5, thereby inhibiting the degradation of cyclic guanosine monophosphate (cGMP) in the smooth muscle of the corpora cavernosa and corpus spongiosum. Inhibition of cGMP degradation leads to prolonged muscle relaxation, vasodilation, and engorgement of the corpora cavernosa, thus prolonging the duration of penile erection. A piperazine derivative, phosphodiesterase type 5 inhibitor, and vasodilator, it is used as a urological medication to treat erectile dysfunction. Drug Indications Vardenafil is indicated for the treatment of erectile dysfunction. Treatment of erectile dysfunction in adult men. Erectile dysfunction is defined as the inability to achieve or maintain an erection sufficient for satisfactory sexual intercourse. Sexual stimulation is required for vardenafil to be effective. Vardenafil is not indicated for use in women. Treatment of erectile dysfunction in adult men. Erectile dysfunction is defined as the inability to achieve or maintain an erection sufficient for satisfactory sexual intercourse. Vivanza requires sexual stimulation to be effective. Vivanza is not suitable for women.
Mechanism of Action
Vardenafil inhibits cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5), an enzyme responsible for degrading cGMP in the corpora cavernosa. Penile erection during sexual stimulation is due to increased blood flow to the penis caused by relaxation of the smooth muscle of the penile arteries and corpora cavernosa. This response is mediated by the release of nitric oxide (NO) from nerve endings and endothelial cells, which stimulates smooth muscle cells to synthesize cGMP. cGMP causes smooth muscle relaxation, increasing blood flow into the corpora cavernosa. The tissue concentration of cGMP is dually regulated by the synthesis and degradation rate of phosphodiesterase (PDE), and the most abundant PDE in the human corpora cavernosa is PDE5. Therefore, vardenafil enhances erectile function by increasing the content of cyclic guanosine monophosphate (cGMP) through inhibition of PDE5.
Penimal erection is a hemodynamic process initiated by the relaxation of smooth muscle in the corpora cavernosa and its associated arterioles. During sexual stimulation, nitric oxide is released from nerve endings and endothelial cells of the corpora cavernosa. Nitric oxide activates guanylate cyclase, leading to increased synthesis of cyclic guanosine monophosphate (cGMP) in the smooth muscle cells of the corpora cavernosa. cGMP, in turn, triggers smooth muscle relaxation, increasing blood flow to the penis and resulting in erection. The tissue concentration of cGMP is dually regulated by the synthesis and degradation rate of phosphodiesterase (PDE). The most abundant PDE in the human corpora cavernosa is cGMP-specific phosphodiesterase type 5 (PDE5). Therefore, PDE5 inhibitors enhance erectile function by increasing cGMP levels. Since sexual stimulation is required to initiate the release of local nitric oxide, PDE5 inhibitors are ineffective without sexual stimulation. In vitro studies have shown that vardenafil is a selective inhibitor of phosphodiesterase type 5 (PDE5). Vardenafil exhibits greater selectivity in inhibiting PDE5 than other known phosphodiesterases (more than 15 times more selective than PDE6; more than 130 times more selective than PDE1; more than 300 times more selective than PDE11; and more than 1000 times more selective than PDE2, 3, 4, 7, 8, 9, and 10).

C23H34CL2N6O4S

561.523

560.173

C, 49.20; H, 6.10; Cl, 12.63; N, 14.97; O, 11.40; S, 5.71

224789-15-5

Vardenafil;224785-90-4;Vardenafil hydrochloride;224785-91-5;Vardenafil hydrochloride trihydrate;330808-88-3

135400189

Typically exists as solid at room temperature

692.2ºC at 760mmHg

214-216°C

372.5ºC

5.17E-19mmHg at 25°C

1.778

1

8

8

34

854

0

CCCC1=NC(=C2C(=O)N=C(C3=C(C=CC(=C3)S(=O)(=O)N4CCN(CC)CC4)OCC)NN12)C.Cl.Cl

NOIHTGOGFDFCBN-UHFFFAOYSA-N

InChI=1S/C23H32N6O4S.2ClH/c1-5-8-20-24-16(4)21-23(30)25-22(26-29(20)21)18-15-17(9-10-19(18)33-7-3)34(31,32)28-13-11-27(6-2)12-14-28/h9-10,15H,5-8,11-14H2,1-4H3,(H,25,26,30)2*1H

2-[2-ethoxy-5-(4-ethylpiperazin-1-yl)sulfonylphenyl]-5-methyl-7-propyl-3H-imidazo[5,1-f][1,2,4]triazin-4-one

BAY 38-9456; BAY-38-9456; Vardenafil dihydrochloride; 224789-15-5; Vardenafil HCL; Vardenafil Dihydrochloride Salt; Vardenafil dihydrochloride [USAN]; BAY 38-9456; 5O8R96XMH7; Nuviva; BAY38-9456; Vardenafil HCl; Levitra; Staxyn; Vivanza

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

May dissolve in DMSO (in most cases), if not, try other solvents such as H2O, Ethanol, or DMF with a minute amount of products to avoid loss of samples

Note: Listed below are some common formulations that may be used to formulate products with low water solubility (e.g. < 1 mg/mL), you may test these formulations using a minute amount of products to avoid loss of samples.

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Injection Formulation 1: DMSO : Tween 80： Saline = 10 : 5 : 85 (i.e. 100 μL DMSO stock solution → 50 μL Tween 80 → 850 μL Saline)
*Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH ₂ O to obtain a clear solution.
Injection Formulation 2: DMSO : PEG300 ：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL DMSO → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)
Injection Formulation 3: DMSO : Corn oil = 10 : 90 (i.e. 100 μL DMSO → 900 μL Corn oil)
Example: Take the Injection Formulation 3 (DMSO : Corn oil = 10 : 90) as an example, if 1 mL of 2.5 mg/mL working solution is to be prepared, you can take 100 μL 25 mg/mL DMSO stock solution and add to 900 μL corn oil, mix well to obtain a clear or suspension solution (2.5 mg/mL, ready for use in animals).

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Injection Formulation 4: DMSO : 20% SBE-β-CD in saline = 10 : 90 [i.e. 100 μL DMSO → 900 μL (20% SBE-β-CD in saline)]
*Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.
Injection Formulation 5: 2-Hydroxypropyl-β-cyclodextrin : Saline = 50 : 50 (i.e. 500 μL 2-Hydroxypropyl-β-cyclodextrin → 500 μL Saline)
Injection Formulation 6: DMSO : PEG300 : castor oil : Saline = 5 : 10 : 20 : 65 (i.e. 50 μL DMSO → 100 μLPEG300 → 200 μL castor oil → 650 μL Saline)
Injection Formulation 7: Ethanol : Cremophor : Saline = 10： 10 : 80 (i.e. 100 μL Ethanol → 100 μL Cremophor → 800 μL Saline)
Injection Formulation 8: Dissolve in Cremophor/Ethanol (50 : 50), then diluted by Saline
Injection Formulation 9: EtOH : Corn oil = 10 : 90 (i.e. 100 μL EtOH → 900 μL Corn oil)
Injection Formulation 10: EtOH : PEG300：Tween 80 : Saline = 10 : 40 : 5 : 45 (i.e. 100 μL EtOH → 400 μLPEG300 → 50 μL Tween 80 → 450 μL Saline)

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Oral Formulation 1: Suspend in 0.5% CMC Na (carboxymethylcellulose sodium)
Oral Formulation 2: Suspend in 0.5% Carboxymethyl cellulose
Example: Take the Oral Formulation 1 (Suspend in 0.5% CMC Na) as an example, if 100 mL of 2.5 mg/mL working solution is to be prepared, you can first prepare 0.5% CMC Na solution by measuring 0.5 g CMC Na and dissolve it in 100 mL ddH2O to obtain a clear solution; then add 250 mg of the product to 100 mL 0.5% CMC Na solution, to make the suspension solution (2.5 mg/mL, ready for use in animals).

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Oral Formulation 3: Dissolved in PEG400
Oral Formulation 4: Suspend in 0.2% Carboxymethyl cellulose
Oral Formulation 5: Dissolve in 0.25% Tween 80 and 0.5% Carboxymethyl cellulose
Oral Formulation 6: Mixing with food powders

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Note: Please be aware that the above formulations are for reference only. InvivoChem strongly recommends customers to read literature methods/protocols carefully before determining which formulation you should use for in vivo studies, as different compounds have different solubility properties and have to be formulated differently.

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 (Please use freshly prepared in vivo formulations for optimal results.)