Label: SILDENAFIL tablet

tecovirimat will decrease the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. timololtimolol increases effects of sildenafil by additive vasodilation. timolol increases effects of sildenafil by additive vasodilation.

More about sildenafil

tipranavirtipranavir increases levels of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism.

Increased risk of priapism, hypotension, and other adverse effects.

What Other Drugs Interact with Sildenafil?

Oral Administration

Usual Geriatric Dose for:

tipranavir increases levels of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. tobramycin inhaledtobramycin inhaled and sildenafil both increase nephrotoxicity and/or ototoxicity. Avoid concurrent or sequential use to decrease risk for ototoxicity tobramycin inhaled and sildenafil both increase nephrotoxicity and/or ototoxicity. Avoid concurrent or sequential use to decrease risk for ototoxicity verapamilverapamil will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism.

12.2 Pharmacodynamics

50-mg doseHeadache (21%)Flushing (19%)100-mg dose H5Headache (28%)Flushing (18%)Dyspepsia (17%)Abnormal vision (11%) 25-mg doseFlushing (10%)Nasal congestion (4%)Dyspepsia (3%)Back pain (3%)Dizziness (3%)Myalgia (2%)Nausea (2%)Abnormal vision (1%)Rash (1%) 50-mg doseDyspepsia (9%)Nasal congestion (4%)Back pain (4%)Dizziness (4%)Nausea (3%)Abnormal vision (2%)Myalgia (2%)Rash (2%) 100-mg doseNasal congestion (9%)Back pain (4%)Myalgia (4%)Nausea (3%)Dizziness (3%)Rash (3%) <2% with potential causal relationshipBody as a whole: Face edema, photosensitivity reaction, shock, asthenia, pain, chills, accidental fall, abdominal pain, allergic reaction, chest pain, accidental injuryCardiovascular: Angina pectoris, AV block, migraine, syncope, tachycardia, palpitation, hypotension, postural hypotension, myocardial ischemia, cerebral thrombosis, cardiac arrest, heart failure, abnormal electrocardiogram, cardiomyopathyDigestive: Vomiting, glossitis, colitis, dysphagia, gastritis, gastroenteritis, esophagitis, stomatitis, dry mouth, liver function tests abnormal, rectal hemorrhage, gingivitisHemic and lymphatic: Anemia and leukopeniaMetabolic and nutritional: Thirst, edema, gout, unstable diabetes, hyperglycemia, peripheral edema, hyperuricemia, hypoglycemic reaction, hypernatremiaMusculoskeletal: Arthritis, arthrosis, myalgia, tendon rupture, tenosynovitis, bone pain, myasthenia, synovitisNervous: Ataxia, hypertonia, neuralgia, neuropathy, paresthesia, tremor, vertigo, depression, insomnia, somnolence, abnormal dreams, reflexes decreased, hypesthesiaRespiratory: Asthma, dyspnea, laryngitis, pharyngitis, sinusitis, bronchitis, sputum increased, cough increasedSkin and appendages: Urticaria, herpes simplex, pruritus, sweating, skin ulcer, contact dermatitis, exfoliative dermatitisSpecial senses: Sudden decrease or loss of hearing, mydriasis, conjunctivitis, photophobia, tinnitus, eye pain, ear pain, eye hemorrhage, cataract, dry eyesUrogenital: Cystitis, nocturia, urinary frequency, breast enlargement, urinary incontinence, abnormal ejaculation, genital edema and anorgasmia Body as a whole: Face edema, photosensitivity reaction, shock, asthenia, pain, chills, accidental fall, abdominal pain, allergic reaction, chest pain, accidental injury Cardiovascular: Angina pectoris, AV block, migraine, syncope, tachycardia, palpitation, hypotension, postural hypotension, myocardial ischemia, cerebral thrombosis, cardiac arrest, heart failure, abnormal electrocardiogram, cardiomyopathy Digestive: Vomiting, glossitis, colitis, dysphagia, gastritis, gastroenteritis, esophagitis, stomatitis, dry mouth, liver function tests abnormal, rectal hemorrhage, gingivitis Metabolic and nutritional: Thirst, edema, gout, unstable diabetes, hyperglycemia, peripheral edema, hyperuricemia, hypoglycemic reaction, hypernatremia Musculoskeletal: Arthritis, arthrosis, myalgia, tendon rupture, tenosynovitis, bone pain, myasthenia, synovitis Nervous: Ataxia, hypertonia, neuralgia, neuropathy, paresthesia, tremor, vertigo, depression, insomnia, somnolence, abnormal dreams, reflexes decreased, hypesthesia Respiratory: Asthma, dyspnea, laryngitis, pharyngitis, sinusitis, bronchitis, sputum increased, cough increased Skin and appendages: Urticaria, herpes simplex, pruritus, sweating, skin ulcer, contact dermatitis, exfoliative dermatitis Special senses: Sudden decrease or loss of hearing, mydriasis, conjunctivitis, photophobia, tinnitus, eye pain, ear pain, eye hemorrhage, cataract, dry eyes Urogenital: Cystitis, nocturia, urinary frequency, breast enlargement, urinary incontinence, abnormal ejaculation, genital edema and anorgasmia Cardiovascular and cerebrovascular: Serious cardiovascular (CV), 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 (most, but not all, of these patients had preexisting CV risk factors) Hemic and lymphatic: vaso-occlusive crisis: In a small, prematurely terminated study of sildenafil in patients with pulmonary arterial hypertension (PAH) secondary to sickle cell disease, vaso-occlusive crises requiring hospitalization were commonly reported Nervous: Seizure, seizure recurrence, anxiety, and transient global amnesia Hearing: Cases of sudden decrease or loss of hearing reported postmarketing in temporal association with PDE5 inhibitors 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 Nonarteritic anterior ischemic optic neuropathy (NAION), a cause of decreased vision including permanent loss of vision (reported rarely) Soluble guanylate cyclase (sGC) stimulators (eg, riociguat); concomitant use can cause hypotension Coadministration with nitrates (either regularly and/or intermittently) and nitric oxide donors Consistent with the effects of PDE5 inhibition on the nitric oxide/cyclic guanosine monophosphate pathway, PDE5 inhibitors may potentiate the hypotensive effects of nitrates A suitable time interval following PDE5 dosing for the safe administration of nitrates or nitric oxide donors has not been determined Elicits vasodilatory properties, resulting in mild and transient decreases in blood pressure; monitor for hypotension Use with caution in patients with anatomic deformation of penis (eg, angulation, cavernosal fibrosis, or Peyronie disease), conditions potentially predisposing to priapism (eg, sickle cell anemia, multiple myeloma, or leukemia), cardiovascular disease, bleeding disorders, active peptic ulcer disease, liver disease, renal impairment, multidrug antihypertensive regimens, retinitis pigmentosa, concomitant use of CYP3A4 inhibitors Pulmonary vasodilators may significantly worsen cardiovascular status of patients with pulmonary veno-occlusive disease Sudden decrease or loss of hearing, which may be accompanied by tinnitus and dizziness Stop sildenafil and seek medical care if a sudden loss of vision occurs in 1 or both eyes, which could be a sign of nonarteritic anterior ischemic optic neuropathy (NAION); use with caution, and only when the anticipated benefits outweigh the risks, 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 May cause dose-related impairment of color discrimination; use in patients with retinitis pigmentosa not recommended Potential for cardiac risk with sexual activity in patients with preexisting cardiovascular disease; therefore, treatment for erectile dysfunction generally should not be instituted in men for whom sexual activity is inadvisable because of their underlying cardiovascular status Evaluate underlying causes of erectile dysfunction or BPH before initiating therapy In small, prematurely terminated study of patients with PAH 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; effectiveness of sildenafil in PAH secondary to sickle-cell anemia has not been established; the clinical relevance to men treated for erectile dysfunction with sildenafil is not known Epistaxis occurred in 13% of patients with PAH secondary to connective tissue disease (eg, scleroderma); this effect was not seen in idiopathic PAH; incidence was also higher in those receiving concomitant PO vitamin K antagonist therapy (9%) than in those not receiving such therapy (2%) CYP3A substrate (major route); CYP2C9 substrate (minor route) NitratesContraindicatedConsistent with its known effects on the nitric oxide/cGMP pathway, sildenafil was shown to potentiate the hypotensive effects of nitrates Consistent with its known effects on the nitric oxide/cGMP pathway, sildenafil was shown to potentiate the hypotensive effects of nitrates Strong CYP3A inhibitorsViagra: Modify dose; not to exceed single dose of 25 mg/48 hrRevatio: Not recommendedCoadministration increases systemic exposure of sildenafil and risk of adverse effects Viagra: Modify dose; not to exceed single dose of 25 mg/48 hr Coadministration increases systemic exposure of sildenafil and risk of adverse effects Moderate-to-strong CYP3A inducersRevatio: Modify dose; upward dose titration may be needed if coadministeredCoadministration with moderate-to-strong CYP3A inducers (eg, bosentan) decreases the sildenafil exposure and possibly reduces efficacy Revatio: Modify dose; upward dose titration may be needed if coadministered Coadministration with moderate-to-strong CYP3A inducers (eg, bosentan) decreases the sildenafil exposure and possibly reduces efficacy Other PDE5 inhibitorsAvoidAdditive adverse effects may occur if coadministered with other PDE5 inhibitors (eg, avanafil, tadalafil, vardenafil) Additive adverse effects may occur if coadministered with other PDE5 inhibitors (eg, avanafil, tadalafil, vardenafil) Alpha-blockers or antihypertensivesModify dose/cautionCoadministration may increase risk of hypotensionParticularly with higher doses used for erectile dysfunction Particularly with higher doses used for erectile dysfunction Limited published data from randomized controlled trials, case-controlled trials, and case series do not re

Patient resources

What should I tell my healthcare provider before taking sildenafil?

verapamil will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. voriconazolevoriconazole will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism.

In case of emergency/overdose

voriconazole will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. zafirlukastzafirlukast will increase the sildenafil 100 mg tab level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. zafirlukast will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism.

• Sildenafil 20 mg tablets are manufactured by several pharmaceutical companies.
• Generic versions are usually less expensive than brand-name options.
• The drug works by inhibiting phosphodiesterase type 5 enzyme.
• Patients should report any unusual symptoms promptly.
• It is important to have a proper diagnosis before starting treatment.

acetazolamideacetazolamide will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. acetazolamide will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism.

anastrozoleanastrozole will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. anastrozole will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. cyclophosphamidecyclophosphamide will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. cyclophosphamide sildenafil citrate chewable tablets will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. drospirenonedrospirenone will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. drospirenone will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. labetalolsildenafil increases effects of labetalol by pharmacodynamic synergism. sildenafil increases effects of labetalol by pharmacodynamic synergism. larotrectiniblarotrectinib will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism.

Before Using

acetazolamide will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. anastrozoleanastrozole will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. anastrozole will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. cyclophosphamidecyclophosphamide will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. cyclophosphamide sildenafil citrate chewable tablets will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism.

Looking for a Different Strength?

drospirenonedrospirenone will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. drospirenone will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. labetalolsildenafil increases effects of labetalol by pharmacodynamic synergism. sildenafil increases effects of labetalol by pharmacodynamic synergism. larotrectiniblarotrectinib will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism.

How sildenafil is used

larotrectinib will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. macitentanmacitentan increases levels of sildenafil by unspecified interaction mechanism. Systemic exposure of steady-state sildenafil (20 mg TID) increased by 15% during coadministration of macitentan (10 mg/day); this change is not considered clinically relevant. macitentan increases levels of sildenafil by unspecified interaction mechanism. Possible additive vasorelaxation, leading to low blood pressure. larotrectinib will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism.

macitentanmacitentan increases levels of sildenafil by unspecified interaction mechanism. Systemic exposure of steady-state sildenafil (20 mg TID) increased by 15% during coadministration of macitentan (10 mg/day); this change is not considered clinically relevant. macitentan increases levels of sildenafil by unspecified interaction mechanism.

Which Makes You Harder?

tecovirimat will decrease the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. timololtimolol increases effects of sildenafil by additive vasodilation. timolol increases effects of sildenafil by additive vasodilation. tipranavirtipranavir increases levels of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Increased risk of priapism, hypotension, and other adverse effects.

How it works

tipranavir increases levels of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. tobramycin inhaledtobramycin inhaled and sildenafil both increase nephrotoxicity and/or ototoxicity. Avoid concurrent or sequential use to decrease risk for ototoxicity tobramycin inhaled and sildenafil both increase nephrotoxicity and/or ototoxicity. Avoid concurrent or sequential use to decrease risk for ototoxicity verapamilverapamil will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. verapamil will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism.

Dosage for pulmonary arterial hypertension (PAH)

voriconazolevoriconazole will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. voriconazole will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. zafirlukastzafirlukast will increase the sildenafil 100 mg tab level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. zafirlukast will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. acetazolamideacetazolamide will increase the level or effect of sildenafil by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Possible additive vasorelaxation, leading to low blood pressure.

• Safe use of sildenafil requires assessment of heart conditions.
• It may cause temporary visual disturbances like blurred vision.
• Do not drive or operate machinery until effects are known.
• Use with caution if you have high or low blood pressure.
• Discuss any other medications with your healthcare provider.

50-mg doseHeadache (21%)Flushing (19%)100-mg dose H5Headache (28%)Flushing (18%)Dyspepsia (17%)Abnormal vision (11%) 25-mg doseFlushing (10%)Nasal congestion (4%)Dyspepsia (3%)Back pain (3%)Dizziness (3%)Myalgia (2%)Nausea (2%)Abnormal vision (1%)Rash (1%) 50-mg doseDyspepsia (9%)Nasal congestion (4%)Back pain (4%)Dizziness (4%)Nausea (3%)Abnormal vision (2%)Myalgia (2%)Rash (2%) 100-mg doseNasal congestion (9%)Back pain (4%)Myalgia (4%)Nausea (3%)Dizziness (3%)Rash (3%) <2% with potential causal relationshipBody as a whole: Face edema, photosensitivity reaction, shock, asthenia, pain, chills, accidental fall, abdominal pain, allergic reaction, chest pain, accidental injuryCardiovascular: Angina pectoris, AV block, migraine, syncope, tachycardia, palpitation, hypotension, postural hypotension, myocardial ischemia, cerebral thrombosis, cardiac arrest, heart failure, abnormal electrocardiogram, cardiomyopathyDigestive: Vomiting, glossitis, colitis, dysphagia, gastritis, gastroenteritis, esophagitis, stomatitis, dry mouth, liver function tests abnormal, rectal hemorrhage, gingivitisHemic and lymphatic: Anemia and leukopeniaMetabolic and nutritional: Thirst, edema, gout, unstable diabetes, hyperglycemia, peripheral edema, hyperuricemia, hypoglycemic reaction, hypernatremiaMusculoskeletal: Arthritis, arthrosis, myalgia, tendon rupture, tenosynovitis, bone pain, myasthenia, synovitisNervous: Ataxia, hypertonia, neuralgia, neuropathy, paresthesia, tremor, vertigo, depression, insomnia, somnolence, abnormal dreams, reflexes decreased, hypesthesiaRespiratory: Asthma, dyspnea, laryngitis, pharyngitis, sinusitis, bronchitis, sputum increased, cough increasedSkin and appendages: Urticaria, herpes simplex, pruritus, sweating, skin ulcer, contact dermatitis, exfoliative dermatitisSpecial senses: Sudden decrease or loss of hearing, mydriasis, conjunctivitis, photophobia, tinnitus, eye pain, ear pain, eye hemorrhage, cataract, dry eyesUrogenital: Cystitis, nocturia, urinary frequency, breast enlargement, urinary incontinence, abnormal ejaculation, genital edema and anorgasmia Body as a whole: Face edema, photosensitivity reaction, shock, asthenia, pain, chills, accidental fall, abdominal pain, allergic reaction, chest pain, accidental injury Cardiovascular: Angina pectoris, AV block, migraine, syncope, tachycardia, palpitation, hypotension, postural hypotension, myocardial ischemia, cerebral thrombosis, cardiac arrest, heart failure, abnormal electrocardiogram, cardiomyopathy Digestive: Vomiting, glossitis, colitis, dysphagia, gastritis, gastroenteritis, esophagitis, stomatitis, dry mouth, liver function tests abnormal, rectal hemorrhage, gingivitis Metabolic and nutritional: Thirst, edema, gout, unstable diabetes, hyperglycemia, peripheral edema, hyperuricemia, hypoglycemic reaction, hypernatremia Musculoskeletal: Arthritis, arthrosis, myalgia, tendon rupture, tenosynovitis, bone pain, myasthenia, synovitis Nervous: Ataxia, hypertonia, neuralgia, neuropathy, paresthesia, tremor, vertigo, depression, insomnia, somnolence, abnormal dreams, reflexes decreased, hypesthesia Respiratory: Asthma, dyspnea, laryngitis, pharyngitis, sinusitis, bronchitis, sputum increased, cough increased Skin and appendages: Urticaria, herpes simplex, pruritus, sweating, skin ulcer, contact dermatitis, exfoliative dermatitis Special senses: Sudden decrease or loss of hearing, mydriasis, conjunctivitis, photophobia, tinnitus, eye pain, ear pain, eye hemorrhage, cataract, dry eyes Urogenital: Cystitis, nocturia, urinary frequency, breast enlargement, urinary incontinence, abnormal ejaculation, genital edema and anorgasmia Cardiovascular and cerebrovascular: Serious cardiovascular (CV), 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 (most, but not all, of these patients had preexisting CV risk factors) Hemic and lymphatic: vaso-occlusive crisis: In a small, prematurely terminated study of sildenafil in patients with pulmonary arterial hypertension (PAH) secondary to sickle cell disease, vaso-occlusive crises requiring hospitalization were commonly reported Nervous: Seizure, seizure recurrence, anxiety, and transient global amnesia Hearing: Cases of sudden decrease or loss of hearing reported postmarketing in temporal association with PDE5 inhibitors 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 Nonarteritic anterior ischemic optic neuropathy (NAION), a cause of decreased vision including permanent loss of vision (reported rarely) Soluble guanylate cyclase (sGC) stimulators (eg, riociguat); concomitant use can cause hypotension Coadministration with nitrates (either regularly and/or intermittently) and nitric oxide donors Consistent with the effects of PDE5 inhibition on the nitric oxide/cyclic guanosine monophosphate pathway, PDE5 inhibitors may potentiate the hypotensive effects of nitrates A suitable time interval following PDE5 dosing for the safe administration of nitrates or nitric oxide donors has not been determined Elicits vasodilatory properties, resulting in mild and transient decreases in blood pressure; monitor for hypotension Use with caution in patients with anatomic deformation of penis (eg, angulation, cavernosal fibrosis, or Peyronie disease), conditions potentially predisposing to priapism (eg, sickle cell anemia, multiple myeloma, or leukemia), cardiovascular disease, bleeding disorders, active peptic ulcer disease, liver disease, renal impairment, multidrug antihypertensive regimens, retinitis pigmentosa, concomitant use of CYP3A4 inhibitors Pulmonary vasodilators may significantly worsen cardiovascular status of patients with pulmonary veno-occlusive disease Sudden decrease or loss of hearing, which may be accompanied by tinnitus and dizziness Stop sildenafil and seek medical care if a sudden loss of vision occurs in 1 or both eyes, which could be a sign of nonarteritic anterior ischemic optic neuropathy (NAION); use with caution, and only when the anticipated benefits outweigh the risks, 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 May cause dose-related impairment of color discrimination; use in patients with retinitis pigmentosa not recommended Potential for cardiac risk with sexual activity in patients with preexisting cardiovascular disease; therefore, treatment for erectile dysfunction generally should not be instituted in men for whom sexual activity is inadvisable because of their underlying cardiovascular status Evaluate underlying causes of erectile dysfunction or BPH before initiating therapy In small, prematurely terminated study of patients with PAH 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; effectiveness of sildenafil in PAH secondary to sickle-cell anemia has not been established; the clinical relevance to men treated for erectile dysfunction with sildenafil is not known Epistaxis occurred in 13% of patients with PAH secondary to connective tissue disease (eg, scleroderma); this effect was not seen in idiopathic PAH; incidence was also higher in those receiving concomitant PO vitamin K antagonist therapy (9%) than in those not receiving such therapy (2%) CYP3A substrate (major route); CYP2C9 substrate (minor route) NitratesContraindicatedConsistent with its known effects on the nitric oxide/cGMP pathway, sildenafil was shown to potentiate the hypotensive effects of nitrates Consistent with its known effects on the nitric oxide/cGMP pathway, sildenafil was shown to potentiate the hypotensive effects of nitrates Strong CYP3A inhibitorsViagra: Modify dose; not to exceed single dose of 25 mg/48 hrRevatio: Not recommendedCoadministration increases systemic exposure of sildenafil and risk of adverse effects Viagra: Modify dose; not to exceed single dose of 25 mg/48 hr Coadministration increases systemic exposure of sildenafil and risk of adverse effects Moderate-to-strong CYP3A inducersRevatio: Modify dose; upward dose titration may be needed if coadministeredCoadministration with moderate-to-strong CYP3A inducers (eg, bosentan) decreases the sildenafil exposure and possibly reduces efficacy Revatio: Modify dose; upward dose titration may be needed if coadministered Coadministration with moderate-to-strong CYP3A inducers (eg, bosentan) decreases the sildenafil exposure and possibly reduces efficacy Other PDE5 inhibitorsAvoidAdditive adverse effects may occur if coadministered with other PDE5 inhibitors (eg, avanafil, tadalafil, vardenafil) Additive adverse effects may occur if coadministered with other PDE5 inhibitors (eg, avanafil, tadalafil, vardenafil) Alpha-blockers or antihypertensivesModify dose/cautionCoadministration may increase risk of hypotensionParticularly with higher doses used for erectile dysfunction Particularly with higher doses used for erectile dysfunction Limited published data from randomized controlled trials, case-controlled trials, and case series do not re