Trade Names:Revatio- Tablets 20 mg
Trade Names:Viagra- Tablets 25 mg- Tablets 50 mg- Tablets 100 mg
Enhances the effect of nitric oxide by inhibiting phosphodiesterase type-5 (PDE5) in the corpus cavernosum of the penis. This results in vasodilation, increased inflow of blood into the corpus cavernosum, and ensuing penile erection upon sexual stimulation.Revatio
Inhibits cGMP-specific PDE5 in the smooth muscle of the pulmonary vasculature, where PDE5 is responsible for degradation of cGMP. This increases cGMP within pulmonary vascular smooth muscle cells resulting in relaxation leading to vasodilation of the pulmonary vascular bed in patients with pulmonary hypertension.
Bioavailability is 40%. T max is 30 to 120 min (mean, 60 min). The drug is rapidly absorbed; when taken with a high-fat meal, the absorption rate is reduced with a mean delay in T max of 60 min and a mean reduction of C max of 29%.
Vd is 105 L; 96% bound to plasma proteins.
Undergoes hepatic metabolism (mainly CYP-450 3A4). The major circulating metabolite results from N-desmethylation.
The t ½ is 4 h. The drug is cleared primarily by the CYP3A4 (major route) and CYP2C9 (minor route) hepatic microsomal isoenzymes, and is excreted primarily in feces (approximately 80%) and, to a lesser extent, in urine (approximately 13%).
Duration of action is up to 4 h.
Severe renal function impairment is associated with increased plasma levels. Consider a starting dose of 25 mg.Hepatic Function ImpairmentViagra
Hepatic function impairment is associated with increased plasma levels. Consider a starting dose of 25 mg.ElderlyViagra
Age older than 65 yr is associated with increased plasma levels. Consider a starting dose of 25 mg.
Treatment of erectile dysfunction ( Viagra ); treatment of pulmonary arterial hypertension to improve exercise ability ( Revatio ).
Enhanced effects leading to prolonged hypotension; hypersensitivity.
PO 50 mg once, 0.5 to 4 h prior to sexual activity. Titration to a 25- or a 100-mg dose may be used based on tolerability or efficacy. The max recommended use is once daily.Dosage Adjustments ( Viagra only)Adults
PO Consider a starting dose of 25 mg in patients older than 65 yr of age, or in patients with hepatic function impairment, severe renal function impairment, or concurrent use of potent CYP-450 3A4 inhibitors (eg, erythromycin, itraconazole, ketoconazole, saquinavir).Alpha-Blockers
Do not take sildenafil 50 or 100 mg within 4 h of alpha-blocker administration; however, a dose of sildenafil 25 mg may be taken at any time.Protease inhibitors
Do not exceed a max single dose of sildenafil 25 mg in a 48-h period.Pulmonary Arterial Hypertension ( Revatio only)Adults
PO 20 mg 3 times daily.
Store at controlled room temperature (59° to 86°F).
Administration may result in an additional decrease in BP.Grapefruit juice
Sildenafil plasma concentrations may be prolonged; however, data are conflicting.HMG-CoA reductase inhibitors (eg, simvastatin)
At least 1 case of rhabdomyolysis has been reported during coadministration of sildenafil and simvastatin.Inducers of CYP3A4 (eg, rifampin)
May decrease sildenafil levels.Inhibitors of CYP3A4 (eg, cimetidine, erythromycin, itraconazole, ketoconazole, protease inhibitors [eg, ritonavir, saquinavir], tacrolimus)
Sildenafil plasma levels may be elevated, increasing the risk of adverse reactions.Nitrates
Hypotension (see Contraindications).Opioid analgesics (eg, dihydrocodeine)
Effects of sildenafil may be prolonged, resulting in prolonged erections following orgasm.
None well documented.
Abnormal ECG, angina pectoris, AV block, cardiac arrest, cardiomyopathy, cerebral thrombosis, heart failure, hypotension, myocardial ischemia, palpitation, postural hypotension, syncope, tachycardia (less than 2%); cerebrovascular hemorrhage, hypertension, MI, pulmonary hemorrhage, subarachnoid and intracerebral hemorrhages, sudden cardiac death, transient ischemic attack, ventricular arrhythmia (postmarketing).
Headache (16%); dizziness (2%); abnormal dreams, ataxia, decreased reflexes, depression, hypertonia, hypesthesia, insomnia, migraine, neuralgia, neuropathy, paresthesia, somnolence, tremor, vertigo (less than 2%); anxiety, seizure (postmarketing).
Flushing (10%); rash (2%); contact dermatitis, exfoliative dermatitis, herpes simplex, pruritus, skin ulcer, sweating, urticaria (less than 2%).
Nasal congestion (4%); abnormal vision (mild and transient, predominantly color tinge vision, increased sensitivity to light or blurred vision [3%]); cataract, conjunctivitis, deafness, dry eyes, ear pain, eye hemorrhage, eye pain, mydriasis, photophobia, tinnitus (less than 2%); bloodshot appearance, diplopia, epistaxis, increased IOP, ocular burning, ocular redness, ocular swelling/pressure, paramacular edema, retinal vascular disease or bleeding, temporary vision loss/decreased vision, vitreous detachment/traction (postmarketing).
Dyspepsia (7%); diarrhea (3%); colitis, dry mouth, dysphagia, esophagitis, gastritis, gastroenteritis, gingivitis, glossitis, rectal hemorrhage, stomatitis, vomiting (less than 2%).
UTI (3%); abnormal ejaculation, anorgasmia, breast enlargement, cystitis, genital edema, nocturia, urinary frequency, urinary incontinence (less than 2%); hematuria, priapism, prolonged erection (postmarketing).
Anemia, leukopenia (less than 2%).
Abnormal LFTs (less than 2%).
Edema, gout, hyperglycemia, hypernatremia, hyperuricemia, hypoglycemic reaction, peripheral edema, thirst, unstable diabetes.
Arthritis, arthrosis, bone pain, myalgia, myasthenia, synovitis, tendon rupture, tenosynovitis.
Asthma, bronchitis, dyspnea, increased cough, increased sputum, laryngitis, pharyngitis, sinusitis (less than 2%).
Abdominal pain, accidental falls, accidental injury, allergic reaction, asthenia, chest pain, chills, face edema, pain, photosensitivity, shock (less than 2%).
Category B .
Safety and efficacy not established.
Dose selection should be cautious, usually starting at the lower end of the dosing range, reflecting the greater frequency of decreased hepatic and renal function and comorbidity.Viagra
Consider initial dose of 25 mg in patients older than 65 yr of age.
No dose adjustments are required for renal function impairment (CrCl less than 30 mL/min).Viagra
Consider initial dose of 25 mg in patients with severe renal function impairment (CrCl less than 30 mL/min).
No dose adjustments are required for Child Pugh class A or B hepatic function impairment.Viagra
Consider initial dose of 25 mg in patients with hepatic function impairment.
Use caution when PDE5 inhibitors are coadministered with alpha-blockers because of risk of additive reduction in BP leading to symptomatic hypotension. Viagra doses greater than 25 mg should not be taken within 4 h of taking an alpha-blocker; a dose of Viagra 25 mg may be taken at any time.
Use Viagra with caution in patients with anatomical deformation of the penis (eg, angulation, cavernosal fibrosis, Peyronies disease) or patients prone to priapism (eg, leukemia, multiple myeloma, sickle cell anemia).
Safety of sildenafil is unknown in patients with bleeding disorders or active peptic ulceration.
Exertion from renewed sexual activity may pose a risk of cardiac events such as cerebrovascular hemorrhage, hypertension, MI, sudden cardiac death, transient ischemic attack, and ventricular arrhythmia.
Safety and efficacy have not been established for the use of sildenafil in the following situations: patients who have experienced MI, stroke, or life-threatening arrhythmia in last 6 mo; patients with cardiac failure or coronary artery disease causing unstable angina; patients with resting hypotension (BP less than 90/50) or hypertension (BP greater than 170/110); patients with retinitis pigmentosa; patients currently on bosentan therapy. Use with caution if sildenafil is prescribed in any of these situations.
Pulmonary vasodilators may significantly worsen CV status of patients with PVOD. Administration of Revatio to such patients is not recommended. Consider the possibility of PVOD if signs of pulmonary edema occur when Revatio is administered.
Prior to starting sildenafil, carefully consider whether patients with certain underlying conditions (eg, resting hypotension [BP less than 90/50], fluid depletion, severe left ventricular outflow obstruction, autonomic dysfunction) could be adversely affected by vasodilatory effects.
No data available.
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