Bioequivalence and Bioavailability of an Orodispersible Tablet of Sildenafil Citrate in Healthy Chinese Male Subjects

Key takeaways about sildenafil
5.6 Adverse Reactions with the Concomitant Use of Ritonavir
12.3 Pharmacokinetics
6.1 Clinical Trials Experience

For pediatric patients 45 kg and greater, the recommended dosage is 20 mg three times a day. A maximum dose in pediatric patients has not been identified.

Key takeaways about sildenafil

5.8 Vaso-occlusive Crisis in Patients with Pulmonary Hypertension Secondary to Sickle Cell Disease In a small, prematurely terminated study of patients with pulmonary hypertension (PH) secondary to sickle cell disease, vaso-occlusive crises requiring hospitalization were more commonly reported by patients who received sildenafil citrate than by those randomized to placebo. The following serious adverse events are discussed elsewhere in the labeling: Hypotension [see Warnings and Precautions (5.1)] Vision Loss [see Warnings and Precautions (5.4)] Hearing Loss [see Warnings and Precautions (5.5)] Priapism [see Warnings and Precautions (5.7)] Vaso-occlusive Crisis in Patients with Pulmonary Hypertension Secondary to Sickle Cell Disease [see Warnings and Precautions (5.8) ] 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. The overall frequency of discontinuation in sildenafil citrate-treated patients was 3% (20 mg and 40 mg three times a day) and 8% (80 mg three times a day). Most Common Adverse Reactions in Patients Treated with sildenafil tablets 20 mg, 40 mg, 80 mg and Placebo three times per day in SUPER-1 (More Frequent in sildenafil-Treated Patients than Placebo-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)].

Starting Sildenafil: Recommended First-Time Dosage

In a study to assess the effects of multiple doses of sildenafil citrate on mortality in adults with PAH (StudyA1481324), the lower dose 5 mg TID group showed a higher observed number of deaths (all related to underlying disease/disease under study), serious adverse events, and severe adverse events than the 20 mg and 80 mg TID groups [see Clinical Studies (14)]. Overall, the safety data for sildenafil 80 mg TID dose in Study A1481324 was consistent with the established safety profile of sildenafil in previous adult PAH studies. Sildenafil citrate was studied in a total of 234 PAH pediatric patients 1 to 17 years of age in a 16-week, double-blind placebo-controlled study (STARTS-1); 220 patients continued in a longterm extension study (STARTS-2). Erection increased was observed in 9% of patients treated with sildenafil in STARTS-1. No other new adverse reactions were identified in pediatric patients [see Use in Specific Populations (8.4)].

12.1 Sildenafil Oral Suspension Mechanism of Action

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. It is sildenafil oral jelly 100 mg 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. NAION [see Warnings and Precautions (5.4), Patient Counseling Information (17)]. 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)]. Based on the experience in adults, dose may be titrated to a maximum of 40 mg three times a day for pediatric patients >45 kg, if required, based on symptoms and tolerability [see Clinical Studies (14)]. Sildenafil tablets, USP are supplied as white to off-white, round, biconvex, film-coated tablets debossed with '85' on one side and plain on other side containing sildenafil citrate equivalent to 20 mg of sildenafil. Sildenafil citrate is 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 ( 5.1)] . Phosphodiesterase-5 (PDE5) inhibitors, including sildenafil, may potentiate the hypotensive effects of riociguat. Before prescribing sildenafil tablets, carefully consider whether patients with certain underlying conditions could be adversely affected by such vasodilatory effects (e.g., patients on antihypertensive therapy or with resting hypotension [blood pressure less than 90/50], fluid depletion, severe left ventricular outflow obstruction, or autonomic dysfunction). 5.2 Worsening Pulmonary Vascular Occlusive Disease Pulmonary vasodilators may significantly worsen the cardiovascular status of patients with pulmonary veno-occlusive disease (PVOD). This effect was not seen in idiopathic PAH (sildenafil 3%, placebo 2%) patients. The incidence of epistaxis was also higher in sildenafil-treated patients with a concomitant oral vitamin K antagonist (9% versus 2% in those not treated with concomitant vitamin K antagonist).

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5.6 Adverse Reactions with the Concomitant Use of Ritonavir

This safety observation in pediatrics was not confirmed in a study conducted in adults designed to evaluate this risk (Study A1481324). Inform patients taking sildenafil tablets not to take VIAGRA or other PDE-5 inhibitors. 5.8 Vaso-occlusive Crisis in Patients with Pulmonary Hypertension Secondary to Sickle Cell Disease In a small, prematurely terminated study of patients with pulmonary hypertension (PH) secondary to sickle cell disease, vaso-occlusive crises requiring hospitalization were more commonly reported by patients who received sildenafil citrate than by those randomized to placebo. The following serious adverse events are discussed elsewhere in the labeling: Hypotension [see Warnings and Precautions (5.1)] Vision Loss [see Warnings and Precautions (5.4)] Hearing Loss [see Warnings and Precautions (5.5)] Priapism [see Warnings and Precautions (5.7)] Vaso-occlusive Crisis in Patients with Pulmonary Hypertension Secondary to Sickle Cell Disease [see Warnings and Precautions (5.8) ] 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.

Region	Average Cost per Pack	Pack Quantity	Notes
USA	$30 - $50	30 tablets	Generic versions available
UK	£15 - £25	30 tablets	Prescribed or OTC in some areas
India	₹150 - ₹300	10-30 tablets	Widely available, generic options
Australia	AUD 40 - AUD 70	30 tablets	Prescription required

The overall frequency of discontinuation in sildenafil citrate-treated patients was 3% (20 mg and 40 mg three times a day) and 8% (80 mg three times a day). Most Common Adverse Reactions in Patients Treated with sildenafil tablets 20 mg, 40 mg, 80 mg and Placebo three times per day in SUPER-1 (More Frequent in sildenafil-Treated Patients than Placebo-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)]. In a study to assess the effects of multiple doses of sildenafil citrate on mortality in adults with PAH (StudyA1481324), the lower dose 5 mg TID group showed a higher observed number of deaths (all related to underlying disease/disease under study), serious adverse events, and severe adverse events than the 20 mg and 80 mg TID groups [see Clinical Studies (14)]. Overall, the safety data for sildenafil 80 mg TID dose in Study A1481324 was consistent with the established safety profile of sildenafil in previous adult PAH studies. Sildenafil citrate was studied in a total of 234 PAH pediatric patients 1 to 17 years of age in a 16-week, double-blind placebo-controlled study (STARTS-1); 220 patients continued in a longterm extension study (STARTS-2). Erection increased was observed in 9% of patients treated with sildenafil in STARTS-1. No other new adverse reactions were identified in pediatric patients [see Use in Specific Populations (8.4)]. 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. It is sildenafil oral jelly 100 mg 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. NAION [see Warnings and Precautions (5.4), Patient Counseling Information (17)].

For best results, take sildenafil on an empty stomach.
Eating fatty foods may delay its onset.
The medication should be taken approximately 30 minutes before activity.
Do not double dose to compensate for missed doses.
Keep regular medical appointments during treatment.
Report any worsening of symptoms to your doctor.
Never use sildenafil if experiencing chest pain without medical guidance.
Always follow the prescribed health regimen.

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. Reduce the dose of sildenafil tablets 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)]. Risk Summary Limited published data from randomized controlled trials, case-controlled trials, and case series do not report a clear association with sildenafil and major birth defects, miscarriage, or adverse maternal or fetal outcomes when sildenafil is used during pregnancy. There are risks to the mother and fetus from untreated pulmonary arterial hypertension (see Clinical Considerations).

12.3 Pharmacokinetics

Moderate-to-Strong CYP3A Inducers Concomitant use of Sildenafil citrate with moderate-to-strong CYP3A inducers (such as bosentan) decreases the sildenafil exposure. Reduce the dose of sildenafil tablets 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)]. Risk Summary Limited published data from randomized controlled trials, case-controlled trials, and case series do not report a clear association with sildenafil and major birth defects, miscarriage, or adverse maternal or fetal outcomes when sildenafil is used during pregnancy. There are risks to the mother and fetus from untreated pulmonary arterial hypertension (see Clinical Considerations). Animal reproduction studies conducted with sildenafil showed no evidence of embryo-fetal toxicity or teratogenicity at doses up to 32-and 65-times the recommended human dose (RHD) of 20 mg three times a day in rats and rabbits, respectively (see Data).

Incidence not known

In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Clinical Considerations Disease-Associated Maternal and/or Embryo/Fetal Risk Pregnant women with untreated pulmonary arterial hypertension are at risk for heart failure, stroke, preterm delivery, and maternal and fetal death. Data Animal Data No evidence of teratogenicity, embryotoxicity, or fetotoxicity was observed in pregnant rats or rabbits dosed with sildenafil 200 mg/kg/day during organogenesis, a level that is, on a mg/m2 basis, 32-and 65-times, respectively, the recommended human dose (RHD) of 20 mg three times a day. In a rat pre-and postnatal development study, the no-observed-adverse-effect dose was 30 mg/kg/day (equivalent to 5-times the RHD on a mg/m2 basis).

Table 3.5.3: Ascent risk associated with various underlying medical conditions and risk factors

Risk Summary Limited published data from a case report describe the presence of sildenafil and its active metabolite in human milk. The safety and efficacy of Sildenafil citrate have been established in pediatric patients 1 to 17 years old, for the treatment of PAH (WHO Group I) to improve exercise ability and, in patients too young to perform standard exercising testing, pulmonary hemodynamics thought to underly improvements in exercise Use of sildenafil citrate for this indication is supported by evidence from adequate and well-controlled studies in adults with additional PK and safety data in pediatric patients aged 1 year and older [see Adverse Reactions (6.1), Clinical Studies (14)]. The safety and effectiveness of sildenafil citrate have not been established in pediatric patients younger than 1 year of age. During the conduct of the pediatric studies (STARTS-1 and STARTS-2) [see Clinical Studies(14)], an imbalance in the number of deaths was noted: 5/55 (9.1%), 10/74 (13.5%), and 22/100 (22%) in the sildenafil low, medium, and high dose groups, respectively. The causes of death were related to the progression of PAH. Animal reproduction studies conducted with sildenafil showed no evidence of embryo-fetal toxicity or teratogenicity at doses up to 32-and 65-times the recommended human dose (RHD) of 20 mg three times a day in rats and rabbits, respectively (see Data). In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Clinical Considerations Disease-Associated Maternal and/or Embryo/Fetal Risk Pregnant women with untreated pulmonary arterial hypertension are at risk for heart failure, stroke, preterm delivery, and maternal and fetal death. Data Animal Data No evidence of teratogenicity, embryotoxicity, or fetotoxicity was observed in pregnant rats or rabbits dosed with sildenafil 200 mg/kg/day during organogenesis, a level that is, on a mg/m2 basis, 32-and 65-times, respectively, the recommended human dose (RHD) of 20 mg three times a day.

6.1 Clinical Trials Experience

For pediatric patients 45 kg and greater, the recommended dosage is 20 mg three times a day. A maximum dose in pediatric patients has not been identified. Based on the experience in adults, dose may be titrated to a maximum of 40 mg three times a day for pediatric patients >45 kg, if required, based on symptoms and tolerability [see Clinical Studies (14)]. Sildenafil tablets, USP are supplied as white to off-white, round, biconvex, film-coated tablets debossed with '85' on one side and plain on other side containing sildenafil citrate equivalent to 20 mg of sildenafil. Sildenafil citrate is 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 ( 5.1)] .

Can I take sildenafil every day?

Phosphodiesterase-5 (PDE5) inhibitors, including sildenafil, may potentiate the hypotensive effects of riociguat. Before prescribing sildenafil tablets, carefully consider whether patients with certain underlying conditions could be adversely affected by such vasodilatory effects (e.g., patients on antihypertensive therapy or with resting hypotension [blood pressure less than 90/50], fluid depletion, severe left ventricular outflow obstruction, or autonomic dysfunction). 5.2 Worsening Pulmonary Vascular Occlusive Disease Pulmonary vasodilators may significantly worsen the cardiovascular status of patients with pulmonary veno-occlusive disease (PVOD). This effect was not seen in idiopathic PAH (sildenafil 3%, placebo 2%) patients. The incidence of epistaxis was also higher in sildenafil-treated patients with a concomitant oral vitamin K antagonist (9% versus 2% in those not treated with concomitant vitamin K antagonist).

Erectile dysfunction

When used to treat erectile dysfunction, non-arteritic anterior ischemic optic neuropathy (NAION), a cause of decreased vision including permanent loss of vision, has been reported postmarketing in temporal association with the use of PDE-5 inhibitors, including sildenafil. It is not possible to determine whether these reported events are related directly to the use of sildenafil citrate, to the patient's underlying risk factors for hearing loss, a combination of these factors, or to other factors. Advise patients to seek prompt medical attention in the event of sudden decrease or loss of hearing while taking PDE-5 inhibitors, including sildenafil tablets. 5.6 Combination with Other PDE-5 inhibitors The safety and efficacy of combinations of sildenafil tablets with VIAGRA or other PDE-5 inhibitors have not been studied. Inform patients taking sildenafil tablets not to take VIAGRA or other PDE-5 inhibitors. In a rat pre-and postnatal development study, the no-observed-adverse-effect dose was 30 mg/kg/day (equivalent to 5-times the RHD on a mg/m2 basis). Risk Summary Limited published data from a case report describe the presence of sildenafil and its active metabolite in human milk. The safety and efficacy of Sildenafil citrate have been established in pediatric patients 1 to 17 years old, for the treatment of PAH (WHO Group I) to improve exercise ability and, in patients too young to perform standard exercising testing, pulmonary hemodynamics thought to underly improvements in exercise Use of sildenafil citrate for this indication is supported by evidence from adequate and well-controlled studies in adults with additional PK and safety data in pediatric patients aged 1 year and older [see Adverse Reactions (6.1), Clinical Studies (14)]. The safety and effectiveness of sildenafil citrate have not been established in pediatric patients younger than 1 year of age. During the conduct of the pediatric studies (STARTS-1 and STARTS-2) [see Clinical Studies(14)], an imbalance in the number of deaths was noted: 5/55 (9.1%), 10/74 (13.5%), and 22/100 (22%) in the sildenafil low, medium, and high dose groups, respectively. The causes of death were related to the progression of PAH. This safety observation in pediatrics was not confirmed in a study conducted in adults designed to evaluate this risk (Study A1481324).

Sildenafil tablets 125 mg are often prescribed for pulmonary hypertension.
The dosage can vary depending on the condition.
It’s important to maintain open communication with your doctor.
Alcohol consumption can impair sildenafil’s effectiveness.
Avoid driving if you experience dizziness or vision problems.
Use sildenafil exactly as prescribed to avoid complications.
Do not share medication with others.
Regular medical check-ups are recommended during use.