Sildenafil purchase

During the DB phase, AEs associated with sildenafil use occurred more frequently than in the placebo group, raising an issue about patients being unblinded and introducing bias when answering subjective questionnaires. However, this is a potential issue in many clinical trials and the incidence of AEs related to sildenafil treatment in this study was comparable to that in other trials, for example, in patients with diabetes, 20 depression, 21 or SCI 22 (range, 31–40%). Efficacy of sildenafil is comparable in men with ED and concomitant MS (current study) or SCI.

13, 14 The ability to achieve an erection (IIEF Q3) was improved 1.6-fold in MS patients and 1.8-fold in SCI patients, whereas the ability to maintain an erection (IIEF Q4) improved 1.9-fold in MS patients and 2.1-fold in SCI patients. From the GEQ, the percentage of MS patients reporting improved erections was 90% for sildenafil users compared with 24% for placebo users; the percentage of SCI patients reporting improved erections was 75% for sildenafil users compared with 7% of

placebo

The average age of patients in this study is relatively young and with healthy peripheral neurovasculature a good erectile response is obtained by reflex mechanisms and what psychogenic responsiveness remains available. Sildenafil was well tolerated in this study, as the majority of AEs reported during both phases were mild to moderate in severity and non-serious.

AEs were those known to be associated with the mechanism of action of sildenafil, such as headache, vasodilation, and dyspepsia.

The following clinical investigators contributed to this study: Dr Hans Jacob Hansen, Arhus, Denmark; Dr Andreo Larsen, Helsinki, Finland; Dr Ragnar Stien, Moelv, Norway; Dr Morten Andersen, Moelv, Norway; Dr Sten Fredrikson, Huddunge, Sweden; Professor Clare Fowler, London, UK; Dr Mohammed K.

Sharief, London, UK; Dr Jackie Palace, London, UK; Dr Ronald Murray, Englewood, CO, USA; Dr Douglas Jeffery, Winston-Salem, NC, USA; Dr Michael Kaufman, Charlotte, NC, USA; Dr Mary Ann Picone, Teaneck, NJ, USA; Dr Iqbal Hussain, London, UK; Dr Andrew Goodman, Rochester, NY, USA; Dr Lawrence Jacobs, Buffalo, NY, USA; Dr Aaron Miller, Brooklyn, NY, USA; Dr James Miller, New York, NY, USA; Dr Robert Salant, New York, NY, USA.

These highlights do not include all the information needed to use VIAGRA safely and effectively.

VIAGRA® (sildenafil citrate) tablets, for oral use Initial U.S. Warnings and Precautions, Effects on the Eye (5.3) 08/2017.

VIAGRA is a phosphodiesterase-5 (PDE5) inhibitor indicated for the treatment of erectile dysfunction (ED) (1) DOSAGE AND ADMINISTRATION. For most patients, the recommended dose is 50 mg taken, as needed, approximately 1 hour before sexual activity. However, VIAGRA may be taken anywhere from 30 minutes to 4 hours before sexual activity (2.1) Based on effectiveness and toleration, may increase to a maximum of 100 mg or decrease to 25 mg (2.1) Maximum recommended dosing frequency is once per day (2.1) DOSAGE FORMS AND STRENGTHS.

Tablets: 25 mg, 50 mg, 100 mg (3) CONTRAINDICATIONS. Administration of VIAGRA to patients using nitric oxide donors, such as organic nitrates or organic nitrites in any form.

VIAGRA was shown to potentiate the hypotensive effect of nitrates (4.1, 7.1, 12.2) Known hypersensitivity to sildenafil or any component of tablet (4.2) Administration with guanylate cyclase (GC) stimulators, such as riociguat (4.3) WARNINGS AND PRECAUTIONS.

Patients should not use VIAGRA if sexual activity is inadvisable due to cardiovascular status (5.1) Patients should seek emergency treatment if an erection lasts >4 hours.

Use VIAGRA with caution in patients predisposed to priapism (5.2) Patients should stop VIAGRA and seek medical care if a sudden loss of vision occurs in one or both eyes, which could be a sign of non arteritic anterior ischemic optic neuropathy (NAION). VIAGRA should be used with caution, and only when the anticipated benefits outweigh the risks, in patients with a history of NAION. Patients with a "crowded" optic disc may also be at an increased risk of NAION.

(5.3) Patients should stop VIAGRA and seek prompt medical attention in the event of sudden decrease or loss of hearing (5.4) Caution is advised when VIAGRA is co-administered with alpha-blockers or anti-hypertensives.

Concomitant use may lead to hypotension (5.5) Decreased blood pressure, syncope, and prolonged erection may occur at higher sildenafil exposures.

In

patients

Decrease in VIAGRA dosage is recommended (2.4, 5.6) ADVERSE REACTIONS.

Most common adverse reactions (? 2%) include headache, flushing, dyspepsia, abnormal vision, nasal congestion, back pain, myalgia, nausea, dizziness and rash (6.1) To report SUSPECTED ADVERSE REACTIONS, contact Pfizer at 1-800-438-1985 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . VIAGRA can potentiate the hypotensive effects of nitrates, alpha blockers, and anti-hypertensives (4.1, 5.5, 7.1, 7.2, 7.3, 12.2) With concomitant use of alpha blockers, initiate VIAGRA at 25 mg dose (2.3) CYP3A4 inhibitors (e.g., ritonavir, ketoconazole, itraconazole, erythromycin): Increase VIAGRA exposure (2.4, 7.4, 12.3) Ritonavir: Do not exceed a maximum single dose of 25 mg in a 48 hour period (2.4, 5.6) Erythromycin or strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, saquinavir): Consider a starting dose of 25 mg (2.4, 7.4) USE IN SPECIFIC POPULATIONS. Geriatric use: Consider a starting dose of 25 mg (2.5, 8.5) Severe renal impairment: Consider a starting dose of 25 mg (2.5, 8.6) Hepatic impairment: Consider a starting dose of 25 mg (2.5, 8.7) See 17 for PATIENT COUNSELING INFORMATION and FDA-approved patient labeling.

FULL PRESCRIBING INFORMATION: CONTENTS* 1 INDICATIONS AND USAGE. 4.3 Concomitant Guanylate Cyclase (GC) Stimulators.

5.5 Hypotension when Co-administered with Alpha-blockers or Anti-hypertensives.

5.6 Adverse Reactions with the Concomitant Use of Ritonavir.

5.7 Combination with other PDE5 Inhibitors or Other Erectile Dysfunction Therapies. 5.9 Counseling Patients About Sexually Transmitted Diseases. 13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility.

VIAGRA is indicated for the treatment of erectile dysfunction.

For most patients, the recommended dose is 50 mg taken, as needed, approximately 1 hour before sexual activity.

However, VIAGRA may be taken anywhere from 30 minutes to 4 hours before sexual activity. The maximum recommended dosing frequency is once per day. Based on effectiveness and toleration, the dose may be increased to a maximum recommended dose of 100 mg or decreased to 25 mg. VIAGRA was shown to potentiate the hypotensive effects of nitrates and its administration in patients who use nitric oxide donors such as organic nitrates or organic nitrites in any form is therefore contraindicated [ see Contraindications (4.1), Drug Interactions (7.1), and Clinical Pharmacology (12.2) ] .

When VIAGRA is co-administered with an alpha-blocker, patients should be stable on alpha-blocker therapy prior to initiating VIAGRA treatment and VIAGRA should be initiated at 25 mg [ see Warnings and Precautions (5.5), Drug Interactions (7.2), and Clinical Pharmacology (12.2) ]. The recommended dose for ritonavir-treated patients is 25 mg prior to sexual activity and the recommended maximum dose is 25 mg within a 48 hour period because

concomitant

Consider a starting dose of 25 mg in patients treated with strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, or saquinavir) or erythromycin.

Clinical data have shown that co-administration with saquinavir or erythromycin increased plasma levels of sildenafil by about 3 fold [ see Drug Interactions (7.4) and Clinical Pharmacology (12.3) ].

Consider a starting dose of 25 mg in patients > 65 years, patients with hepatic impairment (e.g., cirrhosis), and patients with severe renal impairment (creatinine clearance see Use in Specific Populations (8.5, 8.6, 8.7) and Clinical Pharmacology (12.3) ] .

VIAGRA is supplied as blue, film-coated, rounded-diamond-shaped tablets containing sildenafil citrate equivalent to 25 mg, 50 mg, or 100 mg of sildenafil.

Tablets are debossed with PFIZER on one side and VGR25, VGR50 or VGR100 on the other to indicate the dosage strengths. Consistent with its known effects on the nitric oxide/cGMP pathway [ see Clinical Pharmacology (12.1, 12.2) ], VIAGRA was shown to potentiate the hypotensive effects of nitrates, and its administration to patients who are using nitric oxide donors such as organic nitrates or organic nitrites in any form either regularly and/or intermittently is therefore contraindicated. After patients have taken VIAGRA, it is unknown when nitrates, if necessary, can be safely administered.

Although plasma levels of sildenafil at 24 purchase sildenafil hours post dose are much lower than at peak concentration, it is unknown whether nitrates can be safely co-administered at this time point [ see Dosage and Administration (2.3), Drug Interactions (7.1), and Clinical Pharmacology (12.2) ].

VIAGRA is contraindicated in patients with a known hypersensitivity to sildenafil, as contained in VIAGRA and REVATIO, or any component of the tablet.

Hypersensitivity reactions have been reported, including rash and urticaria [ see Adverse Reactions (6.1) ] .

4.3 Concomitant Guanylate Cyclase (GC) Stimulators. Do not use VIAGRA in patients who are using a GC stimulator, such as riociguat.

PDE5 inhibitors, including VIAGRA, may potentiate the hypotensive effects of GC stimulators.

There is a potential for cardiac risk of sexual activity in patients with preexisting cardiovascular disease.

Therefore, treatments for erectile dysfunction, including VIAGRA, should not be generally used in men for whom sexual activity is inadvisable because of their underlying cardiovascular status.

The evaluation of erectile dysfunction should include a determination of potential underlying causes and the identification of appropriate treatment following a complete medical assessment. VIAGRA has systemic vasodilatory properties that resulted in transient decreases in supine blood pressure in healthy volunteers (mean maximum decrease of 8.4/5.5 mmHg), [ see Clinical Pharmacology (12.2) ].

While this normally would be expected to be of little consequence in most patients, prior to prescribing VIAGRA, physicians should carefully consider whether their patients with underlying cardiovascular disease could be affected adversely by such vasodilatory effects, especially in combination with sexual activity.

Use with caution in patients with the following underlying conditions which can be particularly sensitive to the actions of vasodilators including VIAGRA – those with left ventricular outflow obstruction (e.g., aortic stenosis, idiopathic hypertrophic subaortic stenosis) and those with severely impaired autonomic control of blood pressure.

There are no controlled clinical data on the safety or efficacy of VIAGRA in the following groups; if prescribed, this should be done with caution.

Patients who have suffered a myocardial infarction, stroke, or life-threatening arrhythmia within the last 6 months; Patients with resting hypotension (BP 170/110 mmHg); Patients with cardiac failure or coronary artery disease causing unstable angina.

Prolonged erection greater than 4 hours and priapism (painful erections greater than 6 hours in duration) have been reported infrequently since market approval of VIAGRA. In the event of an erection that persists longer than 4 hours, the patient should seek immediate medical assistance.

If priapism is not treated immediately, penile tissue damage and permanent loss of potency could result. VIAGRA should be used with caution in patients with anatomical deformation of the penis (such as angulation, cavernosal fibrosis or Peyronie's disease), or in patients who have conditions which may predispose them to priapism (such as sickle cell anemia, multiple myeloma, or leukemia).

However, there are no controlled clinical data on the safety or efficacy of VIAGRA in patients with sickle cell or related anemias. Physicians should advise patients to stop use of all phosphodiesterase type 5 (PDE5) inhibitors, including VIAGRA, and seek medical attention in the event of a sudden loss of vision in one or both eyes. Such an event may be a sign of non-arteritic anterior ischemic optic neuropathy (NAION), a rare condition and a cause of decreased vision including permanent loss of vision, that has been reported rarely post-marketing in temporal association with the use of all PDE5 inhibitors.

Based on published literature, the annual incidence of NAION is 2.5–11.8 cases per 100,000 in males aged ? 50.

An observational case-crossover study evaluated the risk of NAION when PDE5 inhibitor use, as a class, occurred immediately before NAION onset (within 5 half-lives), compared to PDE5 inhibitor use in a prior time period.

The results suggest an approximate 2-fold increase in the risk of NAION, with a risk estimate of 2.15 (95% CI 1.06, 4.34).

A similar study reported a consistent result, with a risk estimate of 2.27 (95% CI 0.99, 5.20).

Other risk factors for NAION, such as the presence of "crowded" optic disc, may have contributed to the occurrence of NAION in these studies. Neither the rare post-marketing reports, nor the association of PDE5 inhibitor use and NAION in the observational studies, substantiate a causal relationship between PDE5 inhibitor use and NAION [ see Adverse Reactions (6.2) ].

Physicians should consider whether their patients with underlying NAION risk factors could be adversely affected by use of PDE5 inhibitors. Individuals who have already experienced NAION are at increased risk of NAION recurrence. Therefore, PDE5 inhibitors, including VIAGRA, should be used with caution in these patients and only when the anticipated benefits outweigh the risks. Individuals with "crowded" optic disc are also considered at greater risk for NAION compared to the general population, however, evidence is insufficient to support screening of prospective users of PDE5 inhibitors, including VIAGRA, for this uncommon condition.

There are no controlled clinical data on the safety or efficacy of VIAGRA in patients with retinitis pigmentosa (a minority of these patients have genetic disorders of retinal phosphodiesterases); if prescribed, this should be done with caution.

Physicians should advise patients to stop taking PDE5 inhibitors, including VIAGRA, and seek prompt medical attention in the event of sudden decrease or loss of hearing.

These events, which may be accompanied by tinnitus and dizziness, have been reported in temporal association to the intake of PDE5 inhibitors, including VIAGRA.

It is not possible to determine whether these events are related directly to the use of PDE5 inhibitors or to other factors [ see Adverse Reactions (6.1, 6.2) ].

5.5 Hypotension when sildenafil purchase Co-administered with Alpha-blockers or Anti-hypertensives. Caution is advised when PDE5 inhibitors are co-administered with alpha-blockers.

PDE5 inhibitors, including VIAGRA, 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. 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.

VIAGRA 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 VIAGRA, 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) ].

5.6 Adverse Reactions with the Concomitant Use of Ritonavir. The concomitant administration of the protease inhibitor ritonavir substantially increases serum concentrations of sildenafil (11-fold increase in AUC).

If VIAGRA is prescribed to patients taking ritonavir, caution should be used. Data from subjects exposed to high systemic levels of sildenafil are limited. Decreased blood pressure, syncope, and prolonged erection were reported in some healthy volunteers exposed to high doses of sildenafil (200–800 mg).

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) ]. 5.7 Combination with other PDE5 Inhibitors or Other Erectile Dysfunction Therapies.

The safety and efficacy of combinations of VIAGRA with other PDE5 Inhibitors, including REVATIO or other pulmonary arterial hypertension (PAH) treatments containing sildenafil, or other treatments for erectile dysfunction have not been studied.

Such combinations may further lower blood pressure. Therefore, the use of such combinations is not recommended.

There have been postmarketing reports of bleeding events in patients who have taken VIAGRA.

A causal relationship between VIAGRA and these events has not been established. In humans, VIAGRA has no effect on bleeding time when taken alone or with aspirin. However, in vitro studies with human platelets indicate that sildenafil potentiates the antiaggregatory effect of sodium nitroprusside (a nitric oxide donor).

In addition, the combination of heparin and VIAGRA had an additive effect on bleeding time in the anesthetized rabbit, but this interaction has not been studied in humans.

The safety of VIAGRA is unknown in patients with bleeding disorders and patients with active peptic ulceration. 5.9 Counseling Patients About Sexually Transmitted Diseases.

The use of VIAGRA offers no protection against sexually transmitted diseases.

Counseling of patients about the protective measures necessary to guard against sexually transmitted diseases, including the Human Immunodeficiency Virus (HIV), may be considered.

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.

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be

directly

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 price of sildenafil 100mg in Table 1 below but generally were reported more frequently.

Table 1: Adverse Reactions Reported by ?2% of Patients Treated with VIAGRA and More Frequent than Placebo in Fixed-Dose Phase II/III Studies Adverse Reaction 25 mg (n=312) 50 mg (n=511) 100 mg (n=506) Placebo (n=607) * Abnormal Vision: Mild to moderate in severity and transient, predominantly color tinge to vision, but also increased sensitivity to light, or blurred vision. Headache 16% 21% 28% 7% Flushing 10% 19% 18% 2% Dyspepsia 3% 9% 17% 2% Abnormal vision* 1% 2% 11% 1% Nasal congestion 4% 4% 9% 2% Back pain 3% 4% 4% 2% Myalgia 2% 2% 4% 1% Nausea 2% 3% 3% 1% Dizziness 3% 4% 3% 2% Rash 1% 2% 3% 1% When VIAGRA 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 VIAGRA at least once weekly, and the following

adverse

In these studies, only one patient discontinued due to abnormal vision. Headache 16% 4% Flushing 10% 1% Dyspepsia 7% 2% Nasal Congestion 4% 2% Abnormal Vision* 3% 0% Back pain 2% 2% Dizziness 2% 1% Rash 2% 1% The following events occurred in 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.

Analysis of the safety database from controlled clinical trials showed no apparent difference in adverse reactions in patients taking VIAGRA with and without anti-hypertensive medication.

This analysis was performed retrospectively, and was not powered to detect any pre-specified difference in adverse reactions. The following adverse reactions have been identified during post approval use of VIAGRA.

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.