13 NONCLINICAL TOXICOLOGY

Sildenafil > sildenafil 12.5 mg


Known hypersensitivity to sildenafil or any component of the injection.

  • This dose is often used as a starting point before increasing if needed.
  • Combining with high-fat meals may slow absorption.
  • Avoid grapefruit juice, as it can affect sildenafil metabolism.

5 WARNINGS AND PRECAUTIONS 5.1 HypotensionSildenafil has vasodilatory properties, resulting in mild and transient decreases in blood pressure.

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In the event of an erection that persists longer than 4 hours, the patient should seek immediate medical assistance. If priapism (painful erection greater than 6 hours in duration) is not treated immediately, penile tissue damage and permanent loss of potency could result.5.8 Vaso-occlusive Crisis in Patients with Pulmonary Hypertension Secondary to Sickle Cell DiseaseIn 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 than by those randomized to placebo. The effectiveness and safety of sildenafil in the treatment of PH secondary to sickle cell disease has not been established. Sildenafil has vasodilatory properties, resulting in mild and transient decreases in blood pressure. Monitor blood pressure when co-administering blood pressure lowering drugs with sildenafil.

Can I take sildenafil every day?

Pulmonary vasodilators may significantly worsen the cardiovascular status of patients with pulmonary veno-occlusive disease (PVOD). Should signs of pulmonary edema occur when sildenafil is administered, consider the possibility of associated PVOD. The incidence of epistaxis was 13% in sildenafil white patients taking sildenafil with PAH secondary to CTD. 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). 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.

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Most patients had underlying anatomic or vascular risk factors for developing NAION, including low cup to disc ratio ("crowded disc"). Cases of sudden decrease or loss of hearing, which may be accompanied by tinnitus and dizziness, have been reported 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, to the patient’s underlying risk factors for hearing loss, a combination of these factors, or to other factors. Inform patients taking sildenafil not to take VIAGRA or other PDE-5 inhibitors. If priapism (painful erection greater than 6 hours in duration) is not treated immediately, penile tissue damage and permanent loss of potency could result. Before prescribing sildenafil, 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).

Pharmacy Name Price per Box (10 tablets) Availability Comments
PharmaPlus $8 Widely available Discount for bulk purchase
MedExpress $9 Usually in stock Generic options available
Local Clinic $12 Prescription required Consultation fee may apply
Online Pharmacy $6 Varies Ensure reputable source

Monitor blood pressure when co-administering blood pressure lowering drugs with sildenafil.5.2 Worsening Pulmonary Vascular Occlusive DiseasePulmonary vasodilators may significantly worsen the cardiovascular status of patients with pulmonary veno-occlusive disease (PVOD). Since there are no clinical data on administration of sildenafil to patients with veno-occlusive disease, administration of sildenafil to such patients is not recommended. Should signs of pulmonary edema occur when sildenafil is administered, consider the possibility of associated PVOD.5.3 EpistaxisThe incidence of epistaxis was 13% in patients taking sildenafil with PAH secondary to CTD.

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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).The safety of sildenafil is unknown in patients with bleeding disorders or active peptic ulceration.5.4 Visual LossWhen 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. Most patients had underlying anatomic or vascular risk factors for developing NAION, including low cup to disc ratio ("crowded disc").Advise patients to seek immediate medical attention in the event of a sudden loss of vision in one or both eyes while taking sildenafil.There are no controlled clinical data on the safety or efficacy of sildenafil in patients with retinitis pigmentosa, a minority of whom have genetic disorders of retinal phosphodiesterases. Therefore, use of sildenafil in patients with retinitis pigmentosa is not recommended.5.5 Hearing LossCases of sudden decrease or loss of hearing, which may be accompanied by tinnitus and dizziness, have been reported in temporal association with the use of PDE-5 inhibitors, including sildenafil.

6.2 Postmarketing Experience

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 than by those randomized to placebo. 6 ADVERSE REACTIONS 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)]6.1 Clinical Trials ExperienceBecause clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical sildenafil spray 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%.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)].Pediatric use information is approved for Viatris Specialty LLC's, REVATIO (sildenafil).

Serious Side Effects

However, due to Viatris Specialty LLC's marketing exclusivity rights, this drug product is not labeled with that information.Sildenafil InjectionAdverse events with sildenafil injection were similar to those seen with oral tablets.6.2 Postmarketing ExperienceThe 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 EventsIn 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.

Hypertension (Off-Label Use)

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 SystemSeizure, seizure recurrenceOphthalmologicNAION [see Warnings and Precautions (5.4), Patient Counseling Information (17)]. In some of the cases, medical conditions and other factors were reported that may have played a role. In many cases, medical follow-up information was limited. It is not possible to determine whether these reported events are related directly to the use of sildenafil, 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.5.6 Combination with other PDE-5 InhibitorsSildenafil is also marketed as VIAGRA®.

Study Name Sample Size Success Rate Main Findings
Randomized Trial A 200 70% Significant improvement in erectile function
Clinical Study B 150 65% Efficacy maintained at 12.5 mg dose
Comparative Study C 100 75% Similar results to higher doses but fewer side effects

The safety and efficacy of combinations of sildenafil with VIAGRA or other PDE-5 inhibitors have not been studied. Inform patients taking sildenafil not to sildenafil citrate tablets for female take VIAGRA or other PDE-5 inhibitors.5.7 PriapismUse sildenafil with caution in patients with anatomical deformation of the penis (e.g., angulation, cavernosal fibrosis, or Peyronie’s disease) or in patients who have conditions, which may predispose them to priapism (e.g., sickle cell anemia, multiple myeloma, or leukemia). In the event of an erection that persists longer than 4 hours, the patient should seek immediate medical assistance. If priapism (painful erection greater than 6 hours in duration) is not treated immediately, penile tissue damage and permanent loss of potency could result.5.8 Vaso-occlusive Crisis in Patients with Pulmonary Hypertension Secondary to Sickle Cell DiseaseIn 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 than by those randomized to placebo. The effectiveness and safety of sildenafil in the treatment of PH secondary to sickle cell disease has not been established. Sildenafil has vasodilatory properties, resulting in mild and transient decreases in blood pressure. Monitor blood pressure when co-administering blood pressure lowering drugs with sildenafil. Pulmonary vasodilators may significantly worsen the cardiovascular status of patients with pulmonary veno-occlusive disease (PVOD). Should signs of pulmonary edema occur when sildenafil is administered, consider the possibility of associated PVOD. The incidence of epistaxis was 13% in sildenafil white patients taking sildenafil with PAH secondary to CTD. 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). 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.

Condition Reason Alternative Action
Use of Nitrates Risk of severe hypotension Consult doctor for alternatives
Severe Cardiovascular Disease Increased risk during physical exertion Adjust dosage or avoid use
Retinitis Pigmentosa Possible risk of vision loss Medical consultation
Hypersensitivity Allergic reaction risk Do not use

Most patients had underlying anatomic or vascular risk factors for developing NAION, including low cup to disc ratio ("crowded disc").

  • Sildenafil 12.5 mg may be prescribed for pulmonary hypertension as well.
  • Dose adjustments may be necessary based on age or medical history.
  • Regular medical checkups help monitor treatment effects.

Cases of sudden decrease or loss of hearing, which may be accompanied by tinnitus and dizziness, have been reported 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, to the patient’s underlying risk factors for hearing loss, a combination of these factors, or to other factors. Inform patients taking sildenafil not to take VIAGRA or other PDE-5 inhibitors. If priapism (painful erection greater than 6 hours in duration) is not treated immediately, penile tissue damage and permanent loss of potency could result. 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 than by those randomized to placebo. 6 ADVERSE REACTIONS 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)]6.1 Clinical Trials ExperienceBecause clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical sildenafil spray 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%.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)].Pediatric use information is approved for Viatris Specialty LLC's, REVATIO (sildenafil). However, due to Viatris Specialty LLC's marketing exclusivity rights, this drug product is not labeled with that information.Sildenafil InjectionAdverse events with sildenafil injection were similar to those seen with oral tablets.6.2 Postmarketing ExperienceThe 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 EventsIn 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 Dosage

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.

12.1 Mechanism of Action

Known hypersensitivity to sildenafil or any component of the injection. 5 WARNINGS AND PRECAUTIONS 5.1 HypotensionSildenafil has vasodilatory properties, resulting in mild and transient decreases in blood pressure. Before prescribing sildenafil, 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). Monitor blood pressure when co-administering blood pressure lowering drugs with sildenafil.5.2 Worsening Pulmonary Vascular Occlusive DiseasePulmonary vasodilators may significantly worsen the cardiovascular status of patients with pulmonary veno-occlusive disease (PVOD). Since there are no clinical data on administration of sildenafil to patients with veno-occlusive disease, administration of sildenafil to such patients is not recommended.

Chronic Obstructive Pulmonary Disease (COPD) (Off-Label Use)

Should signs of pulmonary edema occur when sildenafil is administered, consider the possibility of associated PVOD.5.3 EpistaxisThe incidence of epistaxis was 13% in patients taking sildenafil with PAH secondary to CTD. 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).The safety of sildenafil is unknown in patients with bleeding disorders or active peptic ulceration.5.4 Visual LossWhen 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. Most patients had underlying anatomic or vascular risk factors for developing NAION, including low cup to disc ratio ("crowded disc").Advise patients to seek immediate medical attention in the event of a sudden loss of vision in one or both eyes while taking sildenafil.There are no controlled clinical data on the safety or efficacy of sildenafil in patients with retinitis pigmentosa, a minority of whom have genetic disorders of retinal phosphodiesterases. Therefore, use of sildenafil in patients with retinitis pigmentosa is not recommended.5.5 Hearing LossCases of sudden decrease or loss of hearing, which may be accompanied by tinnitus and dizziness, have been reported in temporal association with the use of PDE-5 inhibitors, including sildenafil.

Altitude Sickness (Off-Label Use)

In some of the cases, medical conditions and other factors were reported that may have played a role. In many cases, medical follow-up information was limited. It is not possible to determine whether these reported events are related directly to the use of sildenafil, 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.5.6 Combination with other PDE-5 InhibitorsSildenafil is also marketed as VIAGRA®. The safety and efficacy of combinations of sildenafil with VIAGRA or other PDE-5 inhibitors have not been studied. Inform patients taking sildenafil not to sildenafil citrate tablets for female take VIAGRA or other PDE-5 inhibitors.5.7 PriapismUse sildenafil with caution in patients with anatomical deformation of the penis (e.g., angulation, cavernosal fibrosis, or Peyronie’s disease) or in patients who have conditions, which may predispose them to priapism (e.g., sickle cell anemia, multiple myeloma, or leukemia). 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 SystemSeizure, seizure recurrenceOphthalmologicNAION [see Warnings and Precautions (5.4), Patient Counseling Information (17)].

  • Not suitable for individuals with severe heart or liver conditions.
  • Always inform your healthcare provider of all medications being taken.
  • Follow-up appointments ensure safe and effective use.