Vardenafil

12.1 Mechanism of Action 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 cGMP-specific phosphodiesterase type 5 (PDE5); therefore, the inhibition of PDE5 enhances erectile function by increasing the amount of cGMP. Because sexual stimulation is required to initiate the local release of nitric oxide, the inhibition of PDE5 has no effect in the absence of sexual stimulation. In vitro studies have shown that vardenafil is a selective inhibitor of PDE5. The inhibitory effect of vardenafil is more selective on PDE5 than for other known phosphodiesterases (>15-fold relative to PDE6, >130-fold relative to PDE1, >300-fold relative to PDE11, and >1,000-fold relative to PDE2, 3, 4, 7, 8, 9, and 10).

1 INDICATIONS AND USAGE Vardenafil hydrochloride tablets are indicated for the treatment of erectile dysfunction. Vardenafil hydrochloride tablets are a phosphodiesterase 5 (PDE5) inhibitor indicated for the treatment of erectile dysfunction. ( 1 )

2 DOSAGE AND ADMINISTRATION Vardenafil hydrochloride tablets are taken as needed: For most patients, the starting dose is 10 mg, up to once daily. Increase to 20 mg or decrease to 5 mg based on efficacy/tolerability. ( 2.1 ) A starting dose of 5 mg vardenafil hydrochloride tablets should be considered in patients ≥ 65 years of age. ( 2.3 ) Vardenafil hydrochloride tablets are taken orally, approximately 60 minutes before sexual activity. ( 2.1 ) The maximum recommended dosing frequency is one tablet per day. ( 2.1 ) Vardenafil hydrochloride tablets may be taken with or without food. ( 2.2 ) If taking strong or moderate inhibitors of CYP3A4, the dose of vardenafil hydrochloride tablets should be adjusted as follows ( 2.4 , 5.2 , 7.2 ): Ritonavir: No more than 2.5 mg in a 72-hour period Cobicistat: No more than 2.5 mg in a 72-hour period Indinavir, saquinavir, atazanavir, ketoconazole 400 mg daily, itraconazole 400 mg daily, clarithromycin: No more than 2.5 mg in a 24-hour period Ketoconazole 200 mg daily, itraconazole 200 mg daily, erythromycin: No more than 5 mg in a 24-hour period. In patients on stable alpha-blocker therapy the recommended starting dose of vardenafil hydrochloride tablets is 5 mg ( 2.4 , 5.6 ) The recommended starting dose of vardenafil hydrochloride tablets is 5 mg in patients with moderate hepatic impairment (Child-Pugh B). The maximum dose in patients with moderate hepatic impairment should not exceed 10 mg. ( 2.3 , 8.6 ) 2.1 General Dose Information For most patients, the recommended starting dose of vardenafil hydrochloride tablets is 10 mg, taken orally, as needed, approximately 60 minutes before sexual activity. The dose may be increased to a maximum recommended dose of 20 mg or decreased to 5 mg based on efficacy and side effects. The maximum recommended dosing frequency is once per day. Sexual stimulation is required for a response to treatment. 2.2 Use with Food Vardenafil hydrochloride tablets can be taken with or without food. 2.3 Use in Specific Populations Geriatrics: A starting dose of 5 mg vardenafil hydrochloride tablets should be considered in patients ≥65 years of age [see Use in Specific Populations (8.5) ]. Hepatic Impairment: For patients with moderate hepatic impairment (Child-Pugh B), a starting dose of 5 mg vardenafil hydrochloride tablets is recommended. The maximum dose in patients with moderate hepatic impairment should not exceed 10 mg. Do not use vardenafil hydrochloride tablets in patients with severe hepatic impairment (Child-Pugh C) [ see Warnings and Precautions (5.8) , Use in Specific Populations (8.6) and Clinical Pharmacology (12.3) ] . Renal Impairment: Do not use vardenafil hydrochloride tablets in patients on renal dialysis [see Warnings and Precautions (5.9 ), Use in Specific Populations (8.7) and Clinical Pharmacology (12.3) ]. 2.4 Concomitant Medications Nitrates: Concomitant use with nitrates and nitric oxide donors in any form is contraindicated [see Contraindications (4.1) ] Guanylate Cyclase (GC) Stimulators, such as riociguat : Concomitant use is contraindicated [see Contraindications (4.2) ]. CYP3A4 Inhibitors: The dosage of vardenafil hydrochloride tablets may require adjustment in patients receiving potent CYP3A4 inhibitors such as ketoconazole, itraconazole, ritonavir, indinavir, saquinavir, atazanavir, cobicistat, and clarithromycin as well as in other patients receiving moderate CYP3A4 inhibitors such as erythromycin [see Drug Interactions (7.2 ) ]. If taking strong or moderate inhibitors of CYP3A4, the dose of vardenafil hydrochloride tablets should be adjusted as follows: Ritonavir: No more than 2.5 mg in a 72-hour period. Indinavir, saquinavir, atazanavir, ketoconazole 400 mg daily, itraconazole 400 mg daily, clarithromycin: No more than 2.5 mg in a 24-hour period. Ketoconazole 200 mg daily, itraconazole 200 mg daily, erythromycin: No more than 5 mg in a 24-hour period. Cobicistat: No more than 2.5 mg in a 72 hour period. Alpha-Blockers: In those patients who are stable on alpha-blocker therapy, phosphodiesterase type 5 (PDE5) inhibitors should be initiated at the lowest recommended starting dose. Concomitant treatment should be initiated only if the patient is stable on his alpha-blocker therapy. Stepwise increase in alpha-blocker dose may be associated with further lowering of blood pressure in patients taking a phosphodiesterase (PDE5) inhibitor including vardenafil. In those patients who are stable on alpha-blocker therapy, vardenafil hydrochloride tablets should be initiated at a dose of 5 mg (2.5 mg when used concomitantly with certain CYP3A4 inhibitors). [See Warnings and Precautions (5.6) and Drug Interactions (7.1) .] A time interval between dosing should be considered when vardenafil hydrochloride tablets are prescribed concomitantly with alpha-blocker therapy [see Clinical Pharmacology (12.2) ] .

6 ADVERSE REACTIONS The following serious adverse reactions with the use of vardenafil hydrochloride tablets (vardenafil) are discussed elsewhere in the labeling: Cardiovascular Effects [see Contraindications (4.1) and Warnings and Precautions (5.1) ] Priapism [see Warnings and Precautions (5.3) ] Effects on Eye [see Warnings and Precautions (5.4) ] Sudden Hearing Loss [see Warnings and Precautions (5.5) ] QT Prolongation [see Warnings and Precautions (5.7) ] Most common adverse reactions reported ( ≥ 2% of patients) are headache, flushing, nasal congestion, dyspepsia, sinusitis, flu syndrome, dizziness, increased creatine kinase, nausea, back pain. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Lannett Company, Inc. at 1-844-834-0530 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch 6.1 Clinical Studies Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. Vardenafil hydrochloride tablets were administered to over 4430 men (mean age 56, range 18-89 years; 81% White, 6% Black, 2% Asian, 2% Hispanic and 9% Other) during controlled and uncontrolled clinical trials worldwide. Over 2200 patients were treated for 6 months or longer and 880 patients were treated for at least 1 year. In placebo-controlled clinical trials, the discontinuation rate due to adverse events was 3.4% for vardenafil hydrochloride tablets compared to 1.1% for placebo. When vardenafil hydrochloride tablets were taken as recommended in placebo-controlled clinical trials, the following adverse reactions were reported (see Table 1 ). Table 1: Adverse Reactions Reported By ≥2% of Patients Treated with Vardenafil Hydrochloride Tablets and More Frequent on Drug than Placebo in Fixed and Flexible Flexible dose studies started all patients at vardenafil hydrochloride tablets 10 mg and allowed decrease in dose to 5 mg or increase in dose to 20 mg based on side effects and efficacy. Dose Randomized, Controlled Trials of 5 mg, 10 mg, or 20 mg Vardenafil Adverse Reaction Percentage of Patients Reporting Reactions Placebo N = 1199 Vardenafil Hydrochloride Tablets N = 2203 Headache 4% 15% Flushing 1% 11% Rhinitis 3% 9% Dyspepsia 1% 4% Accidental Injury All the events listed in the above table were deemed to be adverse drug reactions with the exception of accidental injury. 2% 3% Sinusitis 1% 3% Flu Syndrome 2% 3% Dizziness 1% 2% Increased Creatine Kinase 1% 2% Nausea 1% 2% Back pain was reported in 2.0% of patients treated with vardenafil hydrochloride tablets and 1.7% of patients on placebo. Placebo-controlled trials suggested a dose effect in the incidence of some adverse reactions (headache, flushing, dyspepsia, nausea, and rhinitis) over the 5 mg, 10 mg, and 20 mg doses of vardenafil hydrochloride tablets. All Vardenafil Studies: Vardenafil hydrochloride tablets and vardenafil orally disintegrating tablets have been administered to over 17,000 men (mean age 54.5, range 18–89 years; 70% White, 5% Black, 13% Asian, 4% Hispanic and 8% Other) during controlled and uncontrolled clinical trials worldwide. The number of patients treated for 6 months or longer was 3357, and 1350 patients were treated for at least 1 year. In the placebo-controlled clinical trials for vardenafil hydrochloride tablets and vardenafil orally disintegrating tablets, the discontinuation rate due to adverse events was 1.9% for vardenafil compared to 0.8% for placebo. The following section identifies additional, less frequent adverse reactions (<2%) reported during the clinical development of vardenafil hydrochloride tablets and vardenafil orally disintegrating tablets. Excluded from this list are those adverse reactions that are infrequent and minor, those events that may be commonly observed in the absence of drug therapy, and those events that are not reasonably associated with the drug: Body as a whole: allergic edema and angioedema, feeling unwell, allergic reactions, chest pain Auditory: tinnitus, vertigo Cardiovascular: palpitation, tachycardia, angina pectoris, myocardial infarction, ventricular tachyarrhythmias, hypotension Digestive: nausea, gastrointestinal and abdominal pain, dry mouth, diarrhea, gastroesophageal reflux disease, gastritis, vomiting, increase in transaminases Musculoskeletal: increase in creatine phosphokinase (CPK), increased muscle tone and cramping, myalgia Nervous: paresthesia and dysesthesia, somnolence, sleep disorder, syncope, amnesia, seizure Respiratory: dyspnea, sinus congestion Skin and appendages: erythema, rash Ophthalmologic: visual disturbance, ocular hyperemia, visual color distortions, eye pain and eye discomfort, photophobia, increase in intraocular pressure, conjunctivitis Urogenital: increase in erection, priapism 6.2 Postmarketing Experience The following adverse reactions have been identified during post approv

7 DRUG INTERACTIONS Vardenafil hydrochloride tablets can potentiate the hypotensive effects of nitrates, alpha- blockers, and antihypertensives. ( 7.1 ) 7.1 Potential for Pharmacodynamic Interactions with Vardenafil Hydrochloride Tablets Nitrates: Concomitant use of vardenafil hydrochloride tablets and nitrates and nitric oxide donors is contraindicated. The blood pressure lowering effects of sublingual nitrates (0.4 mg) taken 1 and 4 hours after vardenafil and increases in heart rate when taken at 1, 4 and 8 hours after vardenafil were potentiated by a 20 mg dose of vardenafil hydrochloride tablets in healthy middle-aged subjects. These effects were not observed when vardenafil hydrochloride tablets 20 mg were taken 24 hours before the nitroglycerin (NTG). Potentiation of the hypotensive effects of nitrates for patients with ischemic heart disease has not been evaluated, and concomitant use of vardenafil hydrochloride tablets and nitrates is contraindicated [see Contraindications (4.1) and Clinical Pharmacology (12.2) . Alpha-Blockers: Caution is advised when PDE5 inhibitors are co-administered with alpha-blockers. PDE5 inhibitors, including vardenafil hydrochloride tablets and alpha-adrenergic blocking agents are both vasodilators with blood-pressure-lowering effects. When vasodilators are used in combination, an additive effect on blood pressure may be anticipated. Clinical pharmacology studies have been conducted with co-administration of vardenafil with alfuzosin, terazosin or tamsulosin. [See Dosage and Administration (2.4) , Warnings and Precautions (5.6) , and Clinical Pharmacology (12.2) .] Antihypertensives: Vardenafil hydrochloride tablets may add to the blood pressure lowering effects of antihypertensive agents. In a clinical pharmacology study of patients with erectile dysfunction, single doses of vardenafil 20 mg caused a mean maximum decrease in supine blood pressure of 7 mmHg systolic and 8 mmHg diastolic (compared to placebo), accompanied by a mean maximum increase of heart rate of 4 beats per minute. The maximum decrease in blood pressure occurred between 1 and 4 hours after dosing. Following multiple dosing for 31 days, similar blood pressure responses were observed on Day 31 as on Day 1. Alcohol: Vardenafil hydrochloride tablets (20 mg) did not potentiate the hypotensive effects of alcohol during the 4-hour observation period in healthy volunteers when administered with alcohol (0.5 g/kg body weight, approximately 40 mL of absolute alcohol in a 70 kg person). Alcohol and vardenafil plasma levels were not altered when dosed simultaneously. 7.2 Effect of Other Drugs on Vardenafil In vitro studies Studies in human liver microsomes showed that vardenafil is metabolized primarily by cytochrome P450 (CYP) isoforms 3A4/5, and to a lesser degree by CYP2C9. Therefore, inhibitors of these enzymes are expected to reduce vardenafil clearance [see Dosage and Administration (2.4) and Warnings and Precautions (5.2) ] . In vivo studies Strong CYP3A4 inhibitors Ketoconazole (200 mg once daily) produced a 10-fold increase in vardenafil AUC and a 4-fold increase in maximum concentration (C max ) when co-administered with vardenafil hydrochloride tablets (5 mg) in healthy volunteers. A 5-mg vardenafil hydrochloride tablet dose should not be exceeded in a 24-hour period when used in combination with 200 mg once daily ketoconazole. Since higher doses of ketoconazole (400 mg daily) may result in higher increases in C max and AUC, a single 2.5 mg dose of vardenafil hydrochloride tablets should not be exceeded in a 24-hour period when used in combination with ketoconazole 400 mg daily. [See Dosage and Administration (2.4) and Warnings and Precautions (5) .] Indinavir (800 mg t.i.d.) co-administered with vardenafil hydrochloride tablets 10 mg resulted in a 16-fold increase in vardenafil AUC, a 7-fold increase in vardenafil C max and a 2-fold increase in vardenafil half-life. It is recommended not to exceed a single 2.5 mg vardenafil hydrochloride tablets dose in a 24-hour period when used in combination with indinavir. [See Dosage and Administration (2.4) and Warnings and Precautions (5.2) .] Ritonavir (600 mg b.i.d.) co-administered with vardenafil hydrochloride tablets 5 mg resulted in a 49-fold increase in vardenafil AUC and a 13­ fold increase in vardenafil C max . The interaction is a consequence of blocking hepatic metabolism of vardenafil by ritonavir, a HIV protease inhibitor and a highly strong CYP3A4 inhibitor, which also inhibits CYP2C9. Ritonavir significantly prolonged the half-life of vardenafil to 26 hours. Consequently, it is recommended not to exceed a single 2.5 mg vardenafil hydrochloride tablets dose in a 72-hour period when used in combination with ritonavir. [See Dosage and Administration (2.4) and Warnings and Precautions (5.2) .] . Cobicistat with vardenafil hydrochloride tablets can result in increased plasma concentrations, therefore it is recommended that a single 2.5 mg dose of vardena