SILDENAFIL

Sildenafil citrate, phosphodiesterase-5 (PDE-5) inhibitor, is the citrate salt of sildenafil, a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type-5 (PDE-5). Sildenafil is also marketed as VIAGRA ® for erectile dysfunction. Sildenafil citrate is designated chemically as 1-[[3-(6,7-dihydro-1-methyl-7-oxo-3-propyl-1 H -pyrazolo [4,3- d ] pyrimidin-5-yl)-4-ethoxyphenyl] sulfonyl]-4-methylpiperazine citrate and has the following structural formula: Sildenafil citrate, USP is a white to off-white crystalline powder with a solubility of 3.5 mg/mL in water and a molecular weight of 666.7. Sildenafil tablets, USP are formulated as white to off-white, round shaped film-coated tablets for oral administration. Each tablet contains sildenafil citrate, USP equivalent to 20 mg of sildenafil. In addition to the active ingredient, sildenafil citrate USP, each tablet contains the following inactive ingredients: croscarmellose sodium, dibasic calcium phosphate anhydrous, hypromellose, magnesium stearate, microcrystalline cellulose, polyethylene glycol, polyvinyl alcohol, talc and titanium dioxide. 1

Sildenafil tablets are indicated for the treatment of pulmonary arterial hypertension (WHO Group I) in adults to improve exercise ability and delay clinical worsening. The delay in clinical worsening was demonstrated when sildenafil tablets were added to background epoprostenol therapy [see Clinical Studies (14) ]. Studies establishing effectiveness were short-term (12 to 16 weeks), and included predominately patients with New York Heart Association (NYHA) Functional Class II-III symptoms and idiopathic etiology (71%) or associated with connective tissue disease (CTD) (25%). Sildenafil tablets are a phosphodiesterase-5 (PDE-5) inhibitor indicated for the treatment of pulmonary arterial hypertension (PAH) (WHO Group I) in adults to improve exercise ability and delay clinical worsening. Studies establishing effectiveness were short-term (12 to 16 weeks), and included predominately patients with NYHA Functional Class II-III symptoms. Etiologies were idiopathic (71%) or associated with connective tissue disease (25%). (1)

Tablet: 20 mg three times a day, 4 to 6 hours apart (2.1) 2.1 Sildenafil Tablets Oral Dosage The recommended dosage of sildenafil tablet is 20 mg three times a day [see Clinical Studies (14)]. Pediatric use information is approved for Viatris Specialty LLC’s, REVATIO (sildenafil) tablets. However, due to Viatris Specialty LLC’s marketing exclusivity rights, this drug product is not labeled with that information.

Sildenafil tablets are contraindicated in patients with: Concomitant use of organic nitrates in any form, either regularly or intermittently, because of the greater risk of hypotension [see Warnings and Precautions (5.2) ] . Concomitant use of riociguat, a guanylate cyclase stimulator. PDE-5 inhibitors, including sildenafil, may potentiate the hypotensive effects of riociguat. Known hypersensitivity to sildenafil or any component of the tablet. Hypersensitivity, including anaphylactic reaction, anaphylactic shock and anaphylactoid reaction, has been reported in association with the use of sildenafil. Use with organic nitrates or riociguat (4) History of hypersensitivity reaction to sildenafil or any component of the tablet (4)

The following serious adverse events are discussed elsewhere in the labeling: Mortality with pediatric use [see Warnings and Precautions (5.1) and Use in Specific Populations (8.4) ] Hypotension [see Warnings and Precautions (5.2) ] Vision loss [see Warnings and Precautions (5.5) ] Hearing loss [see Warnings and Precautions (5.6) ] Priapism [see Warnings and Precautions (5.8) ] Vaso-occlusive crisis [see Warnings and Precautions (5.9) ] Most common adverse reactions greater than or equal to 3% and more frequent than placebo were epistaxis, headache, dyspepsia, flushing, insomnia, erythema, dyspnea, and rhinitis. (6.1 , 6.2) To report SUSPECTED ADVERSE REACTIONS, contact AvKARE, Inc. at 1-855-361-3993 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch. 6.1 Clinical Trials 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. In a 12-week, placebo-controlled clinical study and an open-label extension study (SUPER-1) in 277 sildenafil citrate-treated adults with PAH (WHO Group I) [see Clinical Studies (14)] the adverse reactions that were reported by at least 10% of sildenafil citrate -treated patients in any dosing group, and were more frequent in sildenafil citrate -treated patients than in placebo-treated patients are shown in Table 1. Adverse reactions were generally transient and mild to moderate in nature. The overall frequency of discontinuation in sildenafil citrate-treated patients was 3% (20 mg and 40 mg three times a day). The overall frequency of discontinuation for placebo was 3%. Table 1. Most Common Adverse Reactions in Patients with PAH in Study 1 (More Frequent in Sildenafil Citrate-Treated Patients than Placebo-Treated Patients and Incidence ≥3% in Sildenafil Citrate-Treated Patients) In a placebo-controlled fixed dose titration study (PACES-1) of sildenafil citrate (starting with recommended dose of 20 mg and increased to 40 mg and then 80 mg all three times a day) as an adjunct to intravenous epoprostenol in patients with PAH, no new safety issues were identified except for edema, which occurred in 25% of subjects in the combined sildenafil citrate + epoprostenol group compared with 13% of subjects in the epoprostenol group [see Clinical Studies (14)]. Pediatric use information is approved for Viatris Specialty LLC’s, REVATIO (sildenafil) tablets. However, due to Viatris Specialty LLC’s marketing exclusivity rights, this drug product is not labeled with that information. 1 6.2 Postmarketing Experience The following adverse reactions have been identified during post approval use of sildenafil (marketed for both PAH and erectile dysfunction). Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Cardiovascular Events In postmarketing experience with sildenafil at doses indicated for erectile dysfunction, serious cardiovascular, cerebrovascular, and vascular events, including myocardial infarction, sudden cardiac death, ventricular arrhythmia, cerebrovascular hemorrhage, transient ischemic attack, hypertension, pulmonary hemorrhage, and subarachnoid and intracerebral hemorrhages have been reported in temporal association with the use of the drug. Most, but not all, of these patients had preexisting cardiovascular risk factors. Many of these events were reported to occur during or shortly after sexual activity, and a few were reported to occur shortly after the use of sildenafil without sexual activity. Others were reported to have occurred hours to days after use concurrent with sexual activity. It is not possible to determine whether these events are related directly to sildenafil, to sexual activity, to the patient’s underlying cardiovascular disease, or to a combination of these or other factors. Nervous system Seizure, seizure recurrence Ophthalmologic NAION [see Warnings and Precautions (5.5) and Patient Counseling Information (17) ] . To report SUSPECTED ADVERSE REACTIONS, contact AvKARE at 1-855-361-3993 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch

Nitrates Concomitant use of sildenafil citrate with nitrates in any form is contraindicated [see Contraindications (4)]. Strong CYP3A Inhibitors Concomitant use of sildenafil citrate with strong CYP3A inhibitors is not recommended [see Clinical Pharmacology (12.3)]. Moderate-to-Strong CYP3A Inducers Concomitant use of sildenafil citrate with moderate-to-strong CYP3A inducers (such as bosentan) decreases the sildenafil exposure. Dose up-titration of sildenafil citrate may be needed when initiating treatment with moderate-to-strong CYP3A inducers. Reduce the dose of sildenafil to 20 mg three times a day when discontinuing treatment with moderate-to-strong CYP3A inducers [see Clinical Pharmacology (12.3) and Clinical Studies (14)]. Concomitant alpha-blockers or amlodipine: Note additive blood pressure lowering effects. (7) Use with ritonavir and other potent CYP3A inhibitors: Not recommended. (7 , 12.3) Concomitant PDE-5 inhibitors: Avoid use with Viagra or other PDE-5 inhibitors. (5.7)