Data Insights

No dose adjustment is required (including severe impairment

• It is not recommended for use in children or women.
• Overdose symptoms include dizziness, vision changes, and prolonged erections.
• Seek urgent medical help in case of overdose.

CLcr < 30 mL/min) [see Clinical Pharmacology (12.3)].

What Is Silenafil and How Does It Work?

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. 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. 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 sildenafil generic RHD on a mg/m2 basis).

Professional resources

Limited published data from a case report describe the presence of sildenafil and its active metabolite in human milk. There is insufficient information about the effects of sildenafil on the breastfed infant and no information on the effects of sildenafil on milk production. Limited clinical data during lactation preclude a clear determination of the risk of sildenafil to an infant during lactation. The safety and efficacy of sildenafil 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 underlie improvements in exercise. Use of sildenafil 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)].

Clinical monitoring

The safety and effectiveness of sildenafil 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). Given the beneficial effects on clinical worsening and death observed in adults with increasing doses (Study A1481324) and the expected similarity of disease in pediatrics and adults, a causal association for the observed dose-related effect on mortality in pediatric patients is unlikely, and therefore, the available data support dosing in pediatric patients > 45 kg up to a maximum of 40 mg three times a day. In studies with healthy volunteers of single doses up to 800 mg, adverse events

were similar to those seen at lower doses but rates and severities were increased.

• Sildenafil oral solution can interact with nitrates and certain medications.
• Always inform your doctor of all medicines being taken.
• Failure to do so can cause serious adverse effects.

In cases of overdose, standard supportive measures should be adopted as required.

• The cost of sildenafil oral solution varies depending on brand and pharmacy.
• Generic versions are typically less expensive.
• Availability might be limited in some regions or countries.

Renal dialysis is not expected to accelerate clearance as sildenafil is highly

bound to plasma proteins and it is not eliminated in the urine.

• The medication works by relaxing blood vessels in the penis.
• It increases blood flow, resulting in an erection during sexual activity.
• It requires sexual stimulation to be effective.

Sildenafil is also marketed as VIAGRA® for erectile dysfunction.

References (26)

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-treated adults with PAH (WHO Group I) [see Clinical Studies (14)] the adverse reactions that were reported by at least 10% of sildenafil-treated patients in any dosing group, and were more frequent in sildenafil-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-treated patients was 3% (20 mg and 40 mg three times a day) and 8% (80 mg three times a day). The overall frequency of discontinuation for placebo was 3%.

Sildenafil Oral Suspension Dosage and Administration

Most Common Adverse Reactions in Patients Treated with Sildenafil 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 (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 + 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 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 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 long-term extension study (STARTS-2). Erection increased was observed in 9% of patients treated with sildenafil in STARTS-1.

Allergy warning

No other new adverse reactions were identified in pediatric patients [see Use in Specific Populations (8.4)]. Adverse events with sildenafil injection were similar to those seen with oral tablets. 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. 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. Sildenafil for oral suspension is supplied as white to off-white granular powder containing 1.57 g of

Author information

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. NAION [see Warnings and Precautions (5.4), Patient Counseling Information (17)].

Thermal Analysis and Solid-State Characterisation

Concomitant use of sildenafil with nitrates in any form is contraindicated [see Contraindications (4)]. Concomitant use of sildenafil with sildenafil 130mg strong CYP3A inhibitors is not recommended [see Clinical Pharmacology (12.3)]. Concomitant use of sildenafil with moderate-to-strong CYP3A inducers (such as bosentan) decreases the sildenafil exposure. Dose up-titration of sildenafil 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)].

Before taking sildenafil,

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). The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. sildenafil citrate USP (equivalent to 1.12 g sildenafil)

5. Evaluation tests for ODF

Clinical studies of sildenafil did not include sufficient numbers of patients aged 65 and over to determine whether they respond differently from younger patients. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be cautious, reflecting the greater frequency of decreased hepatic, renal, or cardiac function, and of concomitant disease or other drug therapy [see Clinical Pharmacology (12.3)]. No dose adjustment for mild to moderate impairment is required. Severe impairment has not been studied [see Clinical Pharmacology (12.3)]. in an amber PET bottle intended for reconstitution.