7 DRUG INTERACTIONS

PDE5 inhibitors, including sildenafil citrate, 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 occur. In some patients, concomitant use of these two drug classes can lower blood pressure significantly [ see Drug Interactions (7.2)and Clinical Pharmacology (12.2)] leading to symptomatic hypotension (e.g., dizziness, lightheadedness, fainting). Consideration should be given to the following: Patients who demonstrate hemodynamic instability on alpha-blocker therapy alone are at increased risk of symptomatic hypotension with concomitant use of PDE5 inhibitors. Patients should be stable on alpha-blocker therapy prior to initiating a PDE5 inhibitor. In those patients who are stable on alpha-blocker therapy, PDE5 inhibitors should be initiated at the lowest dose [ see Dosage and Administration (2.3)]. In those patients already taking an optimized dose of a PDE5 inhibitor, alpha-blocker therapy should be initiated at the lowest dose.

• Patients with liver or kidney issues need dose adjustments and careful monitoring.
• The recommended maximum dose for sildenafil is generally 100 mg per day.
• Excessive use increases the likelihood of adverse cardiovascular events.
• Use of sildenafil does not provide protection against sexually transmitted infections.
• Some users report a persistent blue-tinged vision after high doses.
• It’s essential to obtain sildenafil from reputable sources to avoid counterfeit products.

Stepwise increase in alpha-blocker dose may be associated with further lowering of blood pressure when taking a PDE5 inhibitor.

Overdose/Missed Dose

PDE5 inhibitors, including sildenafil citrate, 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 occur. In some patients, concomitant use of these two drug classes can lower blood pressure significantly [ see Drug Interactions (7.2)and Clinical Pharmacology (12.2)] leading to symptomatic hypotension (e.g., dizziness, lightheadedness, fainting). Consideration should be given to the following: Patients who demonstrate hemodynamic instability on alpha-blocker therapy alone are at increased risk of symptomatic hypotension with concomitant use of PDE5 inhibitors. Patients should be stable on alpha-blocker therapy prior to initiating a PDE5 inhibitor.

FAQs About Sildenafil Dosage

In those patients who are stable on alpha-blocker therapy, PDE5 inhibitors should be initiated at the lowest dose [ see Dosage and Administration (2.3)]. In those patients already taking an optimized dose of a PDE5 inhibitor, alpha-blocker therapy should be initiated at the lowest dose. Stepwise increase in alpha-blocker dose may be associated with further lowering of blood pressure when taking a PDE5 inhibitor. Safety of combined use of PDE5 inhibitors and alpha-blockers may be affected by other variables, including intravascular volume depletion and other anti-hypertensive drugs. Sildenafil citrate has systemic vasodilatory properties and may further lower blood pressure in patients taking anti-hypertensive medications.

CYP3A4 Inhibitors

In a separate drug interaction study, when amlodipine, 5 mg or 10 mg, and sildenafil citrate, 100 mg were orally administered concomitantly to hypertensive patients mean additional blood pressure reduction of 8 mmHg systolic and 7 mmHg diastolic were noted [ see Drug Interactions (7.3)and Clinical Pharmacology (12.2)]. To decrease the chance of adverse reactions in patients taking ritonavir, a decrease in sildenafil dosage is recommended [ see Dosage and Administration (2.4), Drug Interactions (7.4), and Clinical Pharmacology (12.3)]. The safety and efficacy of combinations of sildenafil tablets, 25 mg, 50 mg and 100 mg with other PDE5 Inhibitors, including sildenafil tablets, 20 mg or other pulmonary arterial hypertension (PAH) treatments containing sildenafil, or other treatments for erectile dysfunction have not been studied. Therefore, the use of such combinations is not recommended. There have been postmarketing reports of bleeding events in patients who have taken sildenafil citrate. Safety of combined use of PDE5 inhibitors and alpha-blockers may be affected by other variables, including intravascular volume depletion and other anti-hypertensive drugs. Sildenafil citrate has systemic vasodilatory properties and may further lower blood pressure in patients taking anti-hypertensive medications.

In a separate drug interaction study, when amlodipine, 5 mg or 10 mg, and sildenafil citrate, 100 mg were orally administered concomitantly to hypertensive patients mean additional blood pressure reduction of 8 mmHg systolic and 7 mmHg diastolic were noted [ see Drug Interactions (7.3)and Clinical Pharmacology (12.2)]. To decrease the chance of adverse reactions in patients taking ritonavir, a decrease in sildenafil dosage is recommended [ see Dosage and Administration (2.4), Drug Interactions (7.4), and Clinical Pharmacology (12.3)].

What Makes Generic Cobra-120 Appealing?

The clinical relevance of this finding to men treated with sildenafil tablets, 25 mg, 50 mg and 100 mg for ED is not known.Nervous:seizure, seizure recurrence, anxiety, and transient global amnesia.Respiratory:epistaxisSpecial senses:Hearing:Cases of sudden decrease or loss of hearing have been reported postmarketing in temporal association with the use of PDE5 inhibitors, including sildenafil citrate. In some of the cases, medical conditions and other factors were reported that may have also played a role in the otologic adverse events. 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 citrate, to the patient’s underlying risk factors for hearing loss, a combination of these factors, or to other factors [ see Warnings and Precautions (5.4)and Patient Counseling Information (17)].Ocular:diplopia, temporary vision loss/decreased vision, ocular redness or bloodshot appearance, ocular burning, ocular swelling/pressure, increased intraocular pressure, retinal edema, retinal vascular disease or bleeding, and vitreous traction/detachment.Non-arteritic anterior ischemic optic neuropathy (NAION), a cause of decreased vision including permanent loss of vision, has been reported rarely post-marketing in temporal association with the use of phosphodiesterase type 5 (PDE5) inhibitors, including sildenafil citrate. Most, but not all, of these patients had underlying anatomic or vascular risk factors for developing NAION, including but not necessarily limited to: low cup to disc ratio (“crowded disc”), age over 50, diabetes, hypertension, coronary artery disease, hyperlipidemia and smoking [ see Warnings and Precautions (5.3)and Patient Counseling Information (17)].Urogenital:prolonged erection, priapism [ see Warnings and Precautions (5.2)and Patient Counseling Information (17)], and hematuria.

Less common

The following are discussed in more detail in other sections of the labeling: Cardiovascular [ see Warnings and Precautions (5.1)] Prolonged Erection and Priapism [ see Warnings and Precautions (5.2)] Effects on the Eye [ see Warnings and Precautions (5.3)] Hearing Loss [ see Warnings and Precautions (5.4)] Hypotension when Co-administered with Alpha-blockers or Anti-hypertensives [ see Warnings and Precautions (5.5)] Adverse Reactions with the Concomitant Use of Ritonavir [ see Warnings and Precautions (5.6)] Combination with other PDE5 Inhibitors or Other Erectile Dysfunction Therapies [ see Warnings and Precautions (5.7)] Effects on Bleeding [ see Warnings and Precautions (5.8)] Counseling Patients About Sexually Transmitted Diseases [ see Warnings and Precautions (5.9)] The most common adverse reactions reported in clinical trials (≥ 2%) are headache, flushing, dyspepsia, abnormal vision, nasal congestion, back pain, myalgia, nausea, dizziness, and rash.

What happens if I take too much sildenafil?

The safety and efficacy of combinations of sildenafil tablets, 25 mg, 50 mg and 100 mg with other PDE5 Inhibitors, including sildenafil tablets, 20 mg or other pulmonary arterial hypertension (PAH) treatments containing sildenafil, or other treatments for erectile dysfunction have not been studied. Therefore, the use of such combinations is not recommended. There have been postmarketing reports of bleeding events in patients who have taken sildenafil citrate. In addition, the combination of heparin and sildenafil citrate had an additive effect on bleeding time in the anesthetized rabbit, but this interaction has not been studied sildenafil citrate tablet in humans.

The safety of sildenafil citrate is unknown in patients with bleeding disorders and patients with active peptic ulceration. The use of sildenafil citrate offers no protection against sexually transmitted diseases. 6 ADVERSE REACTIONS The following are discussed in more detail in other sections of the labeling:Cardiovascular [ see Warnings and Precautions (5.1)]Prolonged Erection and Priapism [ see Warnings and Precautions (5.2)]Effects on the Eye [ see Warnings and Precautions (5.3)]Hearing Loss [ see Warnings and Precautions (5.4)]Hypotension when Co-administered with Alpha-blockers or Anti-hypertensives [ see Warnings and Precautions (5.5)]Adverse Reactions with the Concomitant Use of Ritonavir [ see Warnings and Precautions (5.6)]Combination with other PDE5 Inhibitors or Other Erectile Dysfunction Therapies [ see Warnings and Precautions (5.7)]Effects on Bleeding [ see Warnings and Precautions (5.8)]Counseling Patients About Sexually Transmitted Diseases [ see Warnings and Precautions (5.9)]The most common adverse reactions reported in clinical trials (≥ 2%) are headache, flushing, dyspepsia, abnormal vision, nasal congestion, back pain, myalgia, nausea, dizziness, and rash.6.1 Clinical Trials ExperienceBecause 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 clinical practice.Sildenafil citrate was administered to over 3,700 patients (aged 19 to 87 years) during pre-marketing clinical trials worldwide. Over 550 patients were treated for longer than one year.In placebo-controlled clinical studies, the discontinuation rate due to adverse reactions for sildenafil citrate (2.5%) was not significantly different from placebo (2.3%).In fixed-dose studies, the incidence of some adverse reactions increased with dose. The type of adverse reactions in flexible-dose studies, which reflect the recommended dosage regimen, was similar to that for fixed-dose studies.

At doses above the recommended dose range, adverse reactions were similar to those detailed in Table 1 below but generally were reported more frequently.†Abnormal Vision: Mild to moderate in severity and transient, predominantly color tinge to vision, but also increased sensitivity to light, or blurred vision.When sildenafil citrate was taken as recommended (on an as-needed basis) in flexible-dose, placebo-controlled clinical trials of two to twenty-six weeks duration, patients took sildenafil citrate at least once weekly, and the following adverse reactions were reported:†Abnormal Vision: Mild and transient, predominantly color tinge to vision, but also increased sensitivity to light, or blurred vision.

Medical Use and Dosage Details

How Sildenafil Works to Treat ED

Other Interactions

In these studies, only one patient discontinued due to abnormal sildenafil citrate tablets 150 mg vision.The following events occurred in <2% of patients in controlled clinical trials; a causal relationship to sildenafil citrate is uncertain.

Prescription Required (Rx) to Buy?

This analysis was performed retrospectively, and was not powered to detect any pre-specified difference in adverse reactions.6.2 Postmarketing ExperienceThe following adverse reactions have been identified during post approval use of sildenafil citrate. 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. These events have been chosen for inclusion either due to their seriousness, reporting frequency, lack of clear alternative causation, or a combination of these factors.Cardiovascular and cerebrovascularSerious cardiovascular, cerebrovascular, and vascular events, including myocardial infarction, sudden cardiac death, ventricular arrhythmia, cerebrovascular hemorrhage, transient ischemic attack, hypertension, subarachnoid and intracerebral hemorrhages, and pulmonary hemorrhage have been reported post-marketing in temporal association with the use of sildenafil citrate.

Most, but not all, of these patients had preexisting cardiovascular risk factors.

• Sildenafil citrate 120 mg can cause prolonged erections if misused.
• This dose may increase the risk of cardiovascular side effects.
• Always consult a healthcare provider before taking high doses of sildenafil.
• Combining sildenafil with nitrates can cause dangerous blood pressure drops.
• Side effects may include flushing, nasal congestion, and dizziness.
• Sildenafil is metabolized in the liver and excreted via feces and urine.

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 citrate without sexual activity.

• Regular use of 120 mg sildenafil is not recommended without medical supervision.
• Potential interactions include blood pressure medications and certain antibiotics.
• Always check for contraindications before using sildenafil at high doses.
• The safety profile of large doses has not been well studied in women.
• Avoid driving or operating machinery until you know how sildenafil affects you.
• Keep track of side effects to report to your healthcare provider promptly.

Others were reported to have occurred hours to days after the use of sildenafil citrate and sexual activity.

• Sildenafil 120 mg can cause flushing and nasal congestion as common side effects.
• It is important to follow medical advice to minimize health risks.
• The drug's effectiveness can be influenced by other health conditions like diabetes.
• Consuming grapefruit or grapefruit juice may affect sildenafil’s metabolism.
• Patients should seek emergency care if experiencing an erection lasting longer than 4 hours.
• Sildenafil’s effects typically last about 4-6 hours, depending on individual factors.

It is not possible to determine whether these events are related directly to sildenafil citrate, to sexual activity, to the patient’s underlying cardiovascular disease, to a combination of these factors, or to other factors [ see Warnings and Precautions (5.1)and Patient Counseling Information (17)].Hemic and Lymphatic:vaso-occlusive crisis: In a small, prematurely terminated study of sildenafil tablets, 20 mg (sildenafil) in patients with pulmonary arterial hypertension (PAH) secondary to sickle cell disease, vaso-occlusive crises requiring hospitalization were more commonly reported in patients who received sildenafil than in those randomized to placebo. The clinical relevance of this finding to men treated with sildenafil tablets, 25 mg, 50 mg and 100 mg for ED is not known.Nervous:seizure, seizure recurrence, anxiety, and transient global amnesia.Respiratory:epistaxisSpecial senses:Hearing:Cases of sudden decrease or loss of hearing have been reported postmarketing in temporal association with the use of PDE5 inhibitors, including sildenafil citrate. In some of the cases, medical conditions and other factors were reported that may have also played a role in the otologic adverse events. 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 citrate, to the patient’s underlying risk factors for hearing loss, a combination of these factors, or to other factors [ see Warnings and Precautions (5.4)and Patient Counseling Information (17)].Ocular:diplopia, temporary vision loss/decreased vision, ocular redness or bloodshot appearance, ocular burning, ocular swelling/pressure, increased intraocular pressure, retinal edema, retinal vascular disease or bleeding, and vitreous traction/detachment.Non-arteritic anterior ischemic optic neuropathy (NAION), a cause of decreased vision including permanent loss of vision, has been reported rarely post-marketing in temporal association with the use of phosphodiesterase type 5 (PDE5) inhibitors, including sildenafil citrate. Most, but not all, of these patients had underlying anatomic or vascular risk factors for developing NAION, including but not necessarily limited to: low cup to disc ratio (“crowded disc”), age over 50, diabetes, hypertension, coronary artery disease, hyperlipidemia and smoking [ see Warnings and Precautions (5.3)and Patient Counseling Information (17)].Urogenital:prolonged erection, priapism [ see Warnings and Precautions (5.2)and Patient Counseling Information (17)], and hematuria.

Usual Adult Dose for Pulmonary Hypertension

In addition, the combination of heparin and sildenafil citrate had an additive effect on bleeding time in the anesthetized rabbit, but this interaction has not been studied sildenafil citrate tablet in humans. The safety of sildenafil citrate is unknown in patients with bleeding disorders and patients with active peptic ulceration. The use of sildenafil citrate offers no protection against sexually transmitted diseases. 6 ADVERSE REACTIONS The following are discussed in more detail in other sections of the labeling:Cardiovascular [ see Warnings and Precautions (5.1)]Prolonged Erection and Priapism [ see Warnings and Precautions (5.2)]Effects on the Eye [ see Warnings and Precautions (5.3)]Hearing Loss [ see Warnings and Precautions (5.4)]Hypotension when Co-administered with Alpha-blockers or Anti-hypertensives [ see Warnings and Precautions (5.5)]Adverse Reactions with the Concomitant Use of Ritonavir [ see Warnings and Precautions (5.6)]Combination with other PDE5 Inhibitors or Other Erectile Dysfunction Therapies [ see Warnings and Precautions (5.7)]Effects on Bleeding [ see Warnings and Precautions (5.8)]Counseling Patients About Sexually Transmitted Diseases [ see Warnings and Precautions (5.9)]The most common adverse reactions reported in clinical trials (≥ 2%) are headache, flushing, dyspepsia, abnormal vision, nasal congestion, back pain, myalgia, nausea, dizziness, and rash.6.1 Clinical Trials ExperienceBecause 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 clinical practice.Sildenafil citrate was administered to over 3,700 patients (aged 19 to 87 years) during pre-marketing clinical trials worldwide. Over 550 patients were treated for longer than one year.In placebo-controlled clinical studies, the discontinuation rate due to adverse reactions for sildenafil citrate (2.5%) was not significantly different from placebo (2.3%).In fixed-dose studies, the incidence of some adverse reactions increased with dose.

Dosage Forms & Strengths

The type of adverse reactions in flexible-dose studies, which reflect the recommended dosage regimen, was similar to that for fixed-dose studies. At doses above the recommended dose range, adverse reactions were similar to those detailed in Table 1 below but generally were reported more frequently.†Abnormal Vision: Mild to moderate in severity and transient, predominantly color tinge to vision, but also increased sensitivity to light, or blurred vision.When sildenafil citrate was taken as recommended (on an as-needed basis) in flexible-dose, placebo-controlled clinical trials of two to twenty-six weeks duration, patients took sildenafil citrate at least once weekly, and the following adverse reactions were reported:†Abnormal Vision: Mild and transient, predominantly color tinge to vision, but also increased sensitivity to light, or blurred vision. In these studies, only one patient discontinued due to abnormal sildenafil citrate tablets 150 mg vision.The following events occurred in <2% of patients in controlled clinical trials; a causal relationship to sildenafil citrate is uncertain. This analysis was performed retrospectively, and was not powered to detect any pre-specified difference in adverse reactions.6.2 Postmarketing ExperienceThe following adverse reactions have been identified during post approval use of sildenafil citrate. 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.

Interactions that increase your risk for side effects

These events have been chosen for inclusion either due to their seriousness, reporting frequency, lack of clear alternative causation, or a combination of these factors.Cardiovascular and cerebrovascularSerious cardiovascular, cerebrovascular, and vascular events, including myocardial infarction, sudden cardiac death, ventricular arrhythmia, cerebrovascular hemorrhage, transient ischemic attack, hypertension, subarachnoid and intracerebral hemorrhages, and pulmonary hemorrhage have been reported post-marketing in temporal association with the use of sildenafil citrate. 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 citrate without sexual activity. Others were reported to have occurred hours to days after the use of sildenafil citrate and sexual activity. It is not possible to determine whether these events are related directly to sildenafil citrate, to sexual activity, to the patient’s underlying cardiovascular disease, to a combination of these factors, or to other factors [ see Warnings and Precautions (5.1)and Patient Counseling Information (17)].Hemic and Lymphatic:vaso-occlusive crisis: In a small, prematurely terminated study of sildenafil tablets, 20 mg (sildenafil) in patients with pulmonary arterial hypertension (PAH) secondary to sickle cell disease, vaso-occlusive crises requiring hospitalization were more commonly reported in patients who received sildenafil than in those randomized to placebo. The following are discussed in more detail in other sections of the labeling: Cardiovascular [ see Warnings and Precautions (5.1)] Prolonged Erection and Priapism [ see Warnings and Precautions (5.2)] Effects on the Eye [ see Warnings and Precautions (5.3)] Hearing Loss [ see Warnings and Precautions (5.4)] Hypotension when Co-administered with Alpha-blockers or Anti-hypertensives [ see Warnings and Precautions (5.5)] Adverse Reactions with the Concomitant Use of Ritonavir [ see Warnings and Precautions (5.6)] Combination with other PDE5 Inhibitors or Other Erectile Dysfunction Therapies [ see Warnings and Precautions (5.7)] Effects on Bleeding [ see Warnings and Precautions (5.8)] Counseling Patients About Sexually Transmitted Diseases [ see Warnings and Precautions (5.9)] The most common adverse reactions reported in clinical trials (≥ 2%) are headache, flushing, dyspepsia, abnormal vision, nasal congestion, back pain, myalgia, nausea, dizziness, and rash.