Viagra: How a Little Blue Pill Changed the World
Decrease in VIAGRA dosage is recommended (2.4, 5.6)ADVERSE REACTIONSMost 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 INTERACTIONSVIAGRA 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)USE IN SPECIFIC POPULATIONSSee 17 for PATIENT COUNSELING INFORMATION and FDA-approved patient labeling.Revised: 3/2014 VIAGRA is a phosphodiesterase-5 (PDE5) inhibitor indicated for the treatment of erectile dysfunction (ED) (1) For most patients, the recommended dose is 50 mg taken, as needed, approximately 1 hour before sexual activity.
| Dose (mg) | Recommended Age Group | Onset of Action | Duration of Effect |
|---|---|---|---|
| 25 | Adults under 50 | 30-60 minutes | Up to 4 hours |
| 50 | Adults 50-65 | 30-60 minutes | Up to 4-6 hours |
| 100 | Adults over 65 | 30-60 minutes | Up to 4-6 hours |
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) Tablets: 25 mg, 50 mg, 100 mg (3) 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.
Is counterfeit Viagra a worry?
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).
| Tip | Explanation | Best Practice |
|---|---|---|
| Take on an empty stomach | Food can delay absorption | 1 hour before planned activity |
| Avoid alcohol | Can increase side effects | Limit or avoid before use |
| Follow prescribed dose | Overdose risks | Consult doctor for correct dose |
| Avoid grapefruit juice | Interferes with drug metabolism | Drink water instead |
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.
| Product | Dosage | Quantity + Bonus | Price | |
|---|---|---|---|---|
| Viagra Generic | 150mg | 270 + 10 Pills | 326.61€ 311.06€ | |
| Viagra Super Active | 100mg | 90 + 10 Pills | 165.61€ 157.72€ | |
| Viagra Generic | 150mg | 90 + 6 Pills | 147.18€ 140.17€ | |
| Viagra Generic | 25mg | 30 + 4 Pills | 47.97€ 45.69€ | |
| Viagra Generic | 50mg | 60 + 4 Pills | 83.93€ 79.93€ | |
| Viagra Generic | 50mg | 270 + 8 Pills | 198.48€ 189.03€ | |
| Viagra Professional | 100mg | 90 + 2 Pills | 207.09€ 197.23€ | |
| Viagra Professional | 100mg | 20 Pills | 71.14€ 67.75€ | |
| Viagra Generic | 100mg | 90 + 6 Pills | 129.02€ 122.88€ | |
| Viagra Generic | 25mg | 20 Pills | 37.74€ 35.94€ | |
| Viagra Super Active | 100mg | 60 + 8 Pills | 116.84€ 111.28€ | |
| Viagra Professional | 100mg | 30 Pills | 88.92€ 84.69€ | |
| Viagra Generic | 50mg | 360 + 10 Pills | 225.33€ 214.60€ | |
| Viagra Super Active | 100mg | 360 + 30 Pills | 470.93€ 448.50€ | |
| Viagra Generic | 100mg | 20 Pills | 45.58€ 43.41€ |
Concomitant use may lead to hypotension (5.5) Decreased blood pressure, syncope, and prolonged erection sildenafil viagra price may occur at higher sildenafil exposures.
Detection in biological fluids
Decrease in VIAGRA dosage is recommended (2.4, 5.6) Most common adverse reactions (≥ 2%) include headache, flushing, dyspepsia, abnormal vision, nasal congestion, back pain, myalgia, nausea, dizziness and rash (6.1) 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) See 17 for PATIENT COUNSELING INFORMATION and FDA-approved patient labeling. Table of Contents FULL PRESCRIBING INFORMATION: CONTENTS*1 INDICATIONS AND USAGE2 DOSAGE AND ADMINISTRATION2.1 Dosage Information2.2 Use with Food2.3 Dosage Adjustments in Specific Situations2.4 Dosage Adjustments Due to Drug Interactions2.5 Dosage Adjustments in Special Populations3 DOSAGE FORMS AND STRENGTHS4 CONTRAINDICATIONS4.1 Nitrates4.2 Hypersensitivity Reactions5 WARNINGS AND PRECAUTIONS5.1 Cardiovascular5.2 Prolonged Erection and Priapism5.3 Effects on the Eye5.4 Hearing Loss5.5 Hypotension when Co-administered with Alpha-blockers or Anti-hypertensives5.6 Adverse Reactions with the Concomitant Use of Ritonavir5.7 Combination with other PDE5 Inhibitors or Other Erectile Dysfunction Therapies5.8 Effects on Bleeding5.9 Counseling Patients About Sexually Transmitted Diseases6 ADVERSE REACTIONS6.1 Clinical Trials Experience6.2 Postmarketing Experience7 DRUG INTERACTIONS7.1 Nitrates7.2 Alpha-blockers7.3 Amlodipine7.4 Ritonavir and other CYP3A4 inhibitors7.5 Alcohol8 USE IN SPECIFIC POPULATIONS8.1 Pregnancy8.4 Pediatric Use8.5 Geriatric Use8.6 Renal Impairment8.7 Hepatic Impairment10 OVERDOSAGE11 DESCRIPTION12 CLINICAL PHARMACOLOGY12.1 Mechanism of Action12.2 Pharmacodynamics12.3 Pharmacokinetics13 NONCLINICAL TOXICOLOGY13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility14 CLINICAL STUDIES16 HOW SUPPLIED/STORAGE AND HANDLING17 PATIENT COUNSELING INFORMATION*Sections or subsections omitted from the full prescribing information are not listed.
| Feature | Viagra | Cialis | Levitra |
|---|---|---|---|
| Onset of action | 30-60 minutes | 30-60 minutes | 25-60 minutes |
| Duration | Up to 4-6 hours | Up to 36 hours | Up to 4-5 hours |
| Dietary restrictions | No significant restrictions | No significant restrictions | No significant restrictions |
| Price | Moderate | Varies, often higher | Moderate |
Sections or subsections omitted from the full prescribing information are not listed.
- Generic versions of Viagra, containing sildenafil, are available in some markets.
- The price of Viagra can vary depending on brand and dosage.
- Using illicit or unregulated Viagra is risky and can be dangerous.
- Viagra’s chemical formula is C22H30N6O4S.
- It works by relaxing smooth muscle tissue in the penis.
- Consultation with a doctor is essential before starting therapy.
2 DOSAGE AND ADMINISTRATION 2.1 Dosage InformationFor 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.2.3 Dosage Adjustments in Specific SituationsVIAGRA 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)].2.4 Dosage Adjustments Due to Drug InteractionsRitonavirThe 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 administration increased the blood levels of sildenafil by 11-fold [see Warnings and Precautions (5.6), Drug Interactions (7.4), and Clinical Pharmacology (12.3)].CYP3A4 InhibitorsConsider a starting dose of 25 mg in patients treated with strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, or saquinavir) or erythromycin.
What should I do if I forget a dose?
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 25 mg viagra 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 <90/50 mmHg) or hypertension (BP >170/110 mmHg);Patients with cardiac failure or coronary artery disease causing unstable angina.5.2 Prolonged Erection and PriapismProlonged erection greater than 4 hours and priapism (painful erections greater than 6 hours in duration) have been reported infrequently since market approval of VIAGRA. 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.5.3 Effects on the EyePhysicians 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.
Effectiveness and safety
Key takeaway
Clinical data have shown that co-administration with saquinavir or erythromycin increased plasma levels of sildenafil by about 3 fold cheap viagra with dapoxetine [see Drug Interactions (7.4) and Clinical Pharmacology (12.3)].2.5 Dosage Adjustments in Special PopulationsConsider 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 <30 mL/minute) because administration of VIAGRA in these patients resulted in higher plasma levels of sildenafil [see Use in Specific Populations (8.5, 8.6, 8.7) and Clinical Pharmacology (12.3)].
What other information should I know?
Decrease in VIAGRA dosage is recommended (2.4, 5.6)ADVERSE REACTIONSMost 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 INTERACTIONSVIAGRA 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)USE IN SPECIFIC POPULATIONSSee 17 for PATIENT COUNSELING INFORMATION and FDA-approved patient labeling.Revised: 3/2014 VIAGRA is a phosphodiesterase-5 (PDE5) inhibitor indicated for the treatment of erectile dysfunction (ED) (1) 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) Tablets: 25 mg, 50 mg, 100 mg (3) 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). 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 sildenafil viagra price may occur at higher sildenafil exposures.
Regional issues
Decrease in VIAGRA dosage is recommended (2.4, 5.6) Most common adverse reactions (≥ 2%) include headache, flushing, dyspepsia, abnormal vision, nasal congestion, back pain, myalgia, nausea, dizziness and rash (6.1) 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) See 17 for PATIENT COUNSELING INFORMATION and FDA-approved patient labeling. Table of Contents FULL PRESCRIBING INFORMATION: CONTENTS*1 INDICATIONS AND USAGE2 DOSAGE AND ADMINISTRATION2.1 Dosage Information2.2 Use with Food2.3 Dosage Adjustments in Specific Situations2.4 Dosage Adjustments Due to Drug Interactions2.5 Dosage Adjustments in Special Populations3 DOSAGE FORMS AND STRENGTHS4 CONTRAINDICATIONS4.1 Nitrates4.2 Hypersensitivity Reactions5 WARNINGS AND PRECAUTIONS5.1 Cardiovascular5.2 Prolonged Erection and Priapism5.3 Effects on the Eye5.4 Hearing Loss5.5 Hypotension when Co-administered with Alpha-blockers or Anti-hypertensives5.6 Adverse Reactions with the Concomitant Use of Ritonavir5.7 Combination with other PDE5 Inhibitors or Other Erectile Dysfunction Therapies5.8 Effects on Bleeding5.9 Counseling Patients About Sexually Transmitted Diseases6 ADVERSE REACTIONS6.1 Clinical Trials Experience6.2 Postmarketing Experience7 DRUG INTERACTIONS7.1 Nitrates7.2 Alpha-blockers7.3 Amlodipine7.4 Ritonavir and other CYP3A4 inhibitors7.5 Alcohol8 USE IN SPECIFIC POPULATIONS8.1 Pregnancy8.4 Pediatric Use8.5 Geriatric Use8.6 Renal Impairment8.7 Hepatic Impairment10 OVERDOSAGE11 DESCRIPTION12 CLINICAL PHARMACOLOGY12.1 Mechanism of Action12.2 Pharmacodynamics12.3 Pharmacokinetics13 NONCLINICAL TOXICOLOGY13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility14 CLINICAL STUDIES16 HOW SUPPLIED/STORAGE AND HANDLING17 PATIENT COUNSELING INFORMATION*Sections or subsections omitted from the full prescribing information are not listed. Sections or subsections omitted from the full prescribing information are not listed. 2 DOSAGE AND ADMINISTRATION 2.1 Dosage InformationFor 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.2.3 Dosage Adjustments in Specific SituationsVIAGRA 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)].2.4 Dosage Adjustments Due to Drug InteractionsRitonavirThe 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 administration increased the blood levels of sildenafil by 11-fold [see Warnings and Precautions (5.6), Drug Interactions (7.4), and Clinical Pharmacology (12.3)].CYP3A4 InhibitorsConsider a starting dose of 25 mg in patients treated with strong CYP3A4 inhibitors (e.g., ketoconazole, itraconazole, or saquinavir) or erythromycin.
Does Viagra increase the size of a man’s penis?
Clinical data have shown that co-administration with saquinavir or erythromycin increased plasma levels of sildenafil by about 3 fold cheap viagra with dapoxetine [see Drug Interactions (7.4) and Clinical Pharmacology (12.3)].2.5 Dosage Adjustments in Special PopulationsConsider 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 <30 mL/minute) because administration of VIAGRA in these patients resulted in higher plasma levels of sildenafil [see Use in Specific Populations (8.5, 8.6, 8.7) and Clinical Pharmacology (12.3)]. For most patients, the recommended dose is 50 mg taken, as needed, approximately 1 hour before sexual activity. 4 CONTRAINDICATIONS 4.1 NitratesConsistent 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 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)].4.2 Hypersensitivity ReactionsVIAGRA is contraindicated in patients with a known hypersensitivity to sildenafil, as contained in VIAGRA and REVATIO, or any component of the tablet. 5 WARNINGS AND PRECAUTIONS 5.1 CardiovascularThere is a potential for cardiac risk of sexual activity in patients with preexisting cardiovascular disease. For most patients, the recommended dose is 50 mg taken, as needed, approximately 1 hour before sexual activity.
7.5 Alcohol
What causes an erection?
Viagra (sildenafil) side effects list for healthcare professionals
4 CONTRAINDICATIONS 4.1 NitratesConsistent 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 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)].4.2 Hypersensitivity ReactionsVIAGRA is contraindicated in patients with a known hypersensitivity to sildenafil, as contained in VIAGRA and REVATIO, or any component of the tablet.
- Viagra enhances sexual performance by improving erectile firmness.
- It is available by prescription and should follow a doctor’s guidance.
- Viagra does not increase sexual desire, only aids in erection.
- Alcohol and high-fat meals can reduce Viagra's effectiveness.
- Heart health should be considered before taking Viagra.
- It is important to not take more than one tablet per day.
5 WARNINGS AND PRECAUTIONS 5.1 CardiovascularThere is a potential for cardiac risk of sexual activity in patients with preexisting cardiovascular disease. 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 25 mg viagra 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)].
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Does sildenafil interact with foods or drinks?
Does Viagra work to treat ED?
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 <90/50 mmHg) or hypertension (BP >170/110 mmHg);Patients with cardiac failure or coronary artery disease causing unstable angina.5.2 Prolonged Erection and PriapismProlonged erection greater than 4 hours and priapism (painful erections greater than 6 hours in duration) have been reported infrequently since market approval of VIAGRA. 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).
- Viagra’s effectiveness may vary based on age, health, and dosage.
- It can interact with medications like nitrates, causing dangerous drops in blood pressure.
- Do not use Viagra if you have severe heart or liver conditions.
- Over-the-counter Viagra is not approved and may be unsafe.
- Sexual stimulation is needed for Viagra to work effectively.
- Always buy Viagra from a licensed pharmacy.
However, there are no controlled clinical data on the safety or efficacy of VIAGRA in patients with sickle cell or related anemias.5.3 Effects on the EyePhysicians 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.