Sildenafil Dosage
[1][4][56][67][91][116][131][249] Pharmacokinetics of the drug (as determined by peak plasma concentrations or AUC) are dose proportional over the single-dose range of 1.25-200 mg.[1][4][56][91][116][131] Peak plasma concentrations of sildenafil and its active N-desmethyl metabolite are achieved within 30-120 (median: 60) minutes following oral administration in fasting adults. [1][4][91][127][130][249] Administration with a high-fat meal delays GI absorption, with a reduction in peak plasma concentrations of about 29% and a delay in time to peak plasma concentrations of about 60 minutes; the extent of absorption is not affected. Sildenafil appears to be widely distributed in the body. [1][4][67][116][131] Sildenafil and its major circulating N-desmethyl metabolite are each approximately 96% bound to plasma proteins; protein binding reportedly is independent of plasma concentration. [1][67][91][116][131] Sildenafil is distributed to a limited extent in semen following oral administration, with less than 0.001% of a single dose appearing in semen 90 minutes after dosing in healthy individuals. [1][67] Such concentrations are unlikely to cause any effects in sexual partners exposed to the semen. [67] Plasma sildenafil concentrations appear to decline in a biphasic manner following oral administration, with a terminal elimination half-life of about 4 hours (range: 3-5 hours). [1][4][67][91][116][127][130][131] Sildenafil is metabolized principally via hepatic cytochrome P-450 (CYP) microsomal isoenzymes 3A4 (major route) and 2C9 (minor route). [1][26][67][91][131] Plasma concentrations of the active N-desmethyl metabolite are approximately 40% of those observed with sildenafil, and the metabolite reportedly accounts for about 20% of sildenafil's pharmacologic activity.
See also:
[1][4][56][67][91][116][131][249] Pharmacokinetics of the drug (as determined by peak plasma concentrations or AUC) are dose proportional over the single-dose range of 1.25-200 mg.[1][4][56][91][116][131] Peak plasma concentrations of sildenafil and its active N-desmethyl metabolite are achieved within 30-120 (median: 60) minutes following oral administration in fasting adults. [1][4][91][127][130][249] Administration with a high-fat meal delays GI absorption, with a reduction in peak plasma concentrations of about 29% and a delay in time to peak plasma concentrations of about 60 minutes; the extent of absorption is not affected. Sildenafil appears to be widely distributed in the body. [1][4][67][116][131] Sildenafil and its major circulating N-desmethyl metabolite are each approximately 96% bound to plasma proteins; protein binding reportedly is independent of plasma concentration. [1][67][91][116][131] Sildenafil is distributed to a limited extent in semen following oral administration, with less than 0.001% of a single dose appearing in semen 90 minutes after dosing in healthy individuals.
Duration of Action
[1][67] Such concentrations are unlikely to cause any effects in sexual partners exposed to the semen. [67] Plasma sildenafil concentrations appear to decline in a biphasic manner following oral administration, with a terminal elimination half-life of about 4 hours (range: 3-5 hours). [1][4][67][91][116][127][130][131] Sildenafil is metabolized principally via hepatic cytochrome P-450 (CYP) microsomal isoenzymes 3A4 (major route) and 2C9 (minor route). [1][26][67][91][131] Plasma concentrations of the active N-desmethyl metabolite are approximately 40% of those observed with sildenafil, and the metabolite reportedly accounts for about 20% of sildenafil's pharmacologic activity. [1][67][131] The N-demethylated metabolite, the major circulating metabolite, has a phosphodiesterase selectivity profile similar to that of sildenafil and an in vitro potency for PDE type 5 of approximately 50% of the parent drug.
Why it’s used
[1][116][131] Sildenafil is eliminated mainly in the feces as metabolites following oral administration. [1][67][91][116][131] In healthy adults and those with ED, approximately 80% of an oral dose is excreted as metabolites in feces and 13% is excreted in urine. Importance of instructing patients to read the manufacturer's patient information before starting sildenafil therapy and each time their prescription is refilled. [1]Instruct patients to avoid contraindicated medications such as regular and/or intermittent use of organic nitrates, organic nitrites (e.g., ''poppers''), and riociguat. [1]Inform patients that sildenafil is marketed for erectile dysfunction (Viagra) and pulmonary arterial hypertension (Revatio®). [1][67][131] The N-demethylated metabolite, the major circulating metabolite, has a phosphodiesterase selectivity profile similar to that of sildenafil and an in vitro potency for PDE type 5 of approximately 50% of the parent drug. [1][116][131] Sildenafil is eliminated mainly in the feces as metabolites following oral administration. [1][67][91][116][131] In healthy adults and those with ED, approximately 80% of an oral dose is excreted as metabolites in feces and 13% is excreted in urine. Importance of instructing patients to read the manufacturer's patient information before starting sildenafil therapy and each time their prescription is refilled. [1]Instruct patients to avoid contraindicated medications such as regular and/or intermittent use of organic nitrates, organic nitrites (e.g., ''poppers''), and riociguat.
| Product | Dosage | Quantity + Bonus | Price | |
|---|---|---|---|---|
| Kamagra Polo | 100mg | 84 + 4 Pills | 244.49€ 232.85€ | |
| Viagra Generic | 200mg | 270 + 10 Pills | 379.76€ 361.68€ | |
| Kamagra Soft Tabs | 100mg | 84 + 4 Pills | 233.05€ 221.95€ | |
| Kamagra Polo | 100mg | 60 + 4 Pills | 189.39€ 180.37€ | |
| Viagra Generic | 150mg | 60 + 4 Pills | 111.25€ 105.95€ | |
| Viagra Generic | 200mg | 20 Pills | 61.69€ 58.75€ | |
| Kamagra Soft Tabs | 100mg | 60 + 4 Pills | 180.59€ 171.99€ | |
| Viagra Generic | 25mg | 270 + 8 Pills | 184.26€ 175.49€ | |
| Viagra Generic | 100mg | 90 + 6 Pills | 129.02€ 122.88€ | |
| Viagra Generic | 100mg | 270 + 10 Pills | 270.47€ 257.59€ | |
| Viagra Generic | 150mg | 180 + 10 Pills | 236.46€ 225.20€ | |
| Kamagra Polo | 100mg | 180 + 8 Pills | 446.52€ 425.26€ |
[1]Inform patients that sildenafil is marketed for erectile dysfunction (Viagra) and pulmonary arterial hypertension (Revatio®). [1] Advise patients taking Viagra® not to take Revatio® or other PDE type 5 inhibitors. [1]Advise patients of the potential for sildenafil to augment the blood pressure lowering effect of α-adrenergic blocking agents (e.g., doxazosin) and anti-hypertensive medications (e.g., amlodipine) and concomitant administration may lead to symptomatic hypotension in some patients. [1]Inform patients taking sildenafil for erectile dysfunction and with potential for cardiac risk of sexual activity (e.g., patients with preexisting cardiovascular risk factors) to refrain from further activity and seek medical attention immediately if they experience symptoms (e.g., chest pain, dizziness, nausea) upon initiation of sexual activity. [1]Advise patients to seek immediate medical attention for a sudden loss of vision in one or both eyes while taking sildenafil. [1] Such an event may be a sign of non-arteritic anterior ischemic optic neuropathy (NAION), a sildenafil pick up cause of decreased vision including possible permanent loss of vision. [1]Advise patients to seek prompt medical attention in the event of sudden decrease or loss of hearing while taking sildenafil.
Frequently asked questions
[1] Advise patients taking Viagra® not to take Revatio® or other PDE type 5 inhibitors. [1]Advise patients of the potential for sildenafil to augment the blood pressure lowering effect of α-adrenergic blocking agents (e.g., doxazosin) and anti-hypertensive medications (e.g., amlodipine) and concomitant administration may lead to symptomatic hypotension in some patients. [1]Inform patients taking sildenafil for erectile dysfunction and with potential for cardiac risk of sexual activity (e.g., patients with preexisting cardiovascular risk factors) to refrain from further activity and seek medical attention immediately if they experience symptoms (e.g., chest pain, dizziness, nausea) upon initiation of sexual activity. [1]Advise patients to seek immediate medical attention for a sudden loss of vision in one or both eyes while taking sildenafil. [1] Such an event may be a sign of non-arteritic anterior ischemic optic neuropathy (NAION), a sildenafil pick up cause of decreased vision including possible permanent loss of vision.
Revatio Tablets
[1]Advise patients to seek prompt medical attention in the event of sudden decrease or loss of hearing while taking sildenafil. [1] These events may be accompanied by tinnitus and dizziness. [1]Advise patients to seek prompt medical attention for an erection that lasts more than 4 hours. [1] If it is not treated right away, priapism can permanently damage the penis. [1]Inform patients taking sildenafil for erectile dysfunction that the drug offers no protection against sexually transmitted diseases and patients should use necessary protective measures to guard against such diseases, including the human immunodeficiency virus (HIV).
Organic Nitrates, Nitrites, and Nitric Oxide Donors
[1]Instruct the patient to seek medical attention immediately if they take too much sildenafil. [1]Inform patients of the risk of symptomatic low blood pressure (e.g., dizziness, lightheadedness, fainting). [1] Monitor blood pressure when administering sildenafil in combination with blood pressure lowering drugs (e.g., α-adrenergic blocking agents). [1]Advise patients to take sildenafil with or without food 1 hour or, if needed, 30 minutes to 4 hours before sexual activity. [1] Inform patients that taking sildenafil with a high-fat meal may cause delayed onset. [1] These events may be accompanied by tinnitus and dizziness.
| Patient Group | Typical Dose | Special Considerations |
|---|---|---|
| Adult Men | 150 mg as needed | Take 30-60 minutes before activity |
| Elderly Patients | 75-150 mg based on response | Start at lower dose, monitor side effects |
| Patients with Liver impairment | Lower dose advised | Adjust based on hepatic function |
[1]Advise patients to seek prompt medical attention for an erection that lasts more than 4 hours. [1] If it is not treated right away, priapism can permanently damage the penis. [1]Inform patients taking sildenafil for erectile dysfunction that the drug offers no protection against sexually transmitted diseases and patients should use necessary protective measures to guard against such diseases, including the human immunodeficiency virus (HIV).
- Some patients may experience priapism, a prolonged erection.
- Discontinue use and seek medical attention if this occurs.
- Sildenafil tablets are available in other strengths if needed.
- The medication is not suitable for those with heart disease.
[1]Instruct the patient to seek medical attention immediately if they take too much sildenafil. [1]Inform patients of the risk of symptomatic low blood pressure (e.g., dizziness, lightheadedness, fainting). [1] Monitor blood pressure when administering sildenafil in combination with blood pressure lowering drugs (e.g., α-adrenergic blocking agents). [1]Advise patients to take sildenafil with or without food 1 hour or, if needed, 30 minutes to 4 hours before sexual activity. [1] Inform patients that taking sildenafil with a high-fat meal may cause delayed onset. [1]Advise patient to inform their clinician of existing or contemplated concomitant therapy, including prescription and OTC drugs and dietary or herbal supplements, as well as any concomitant illnesses. [1]Inform patients of other important precautionary information. Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details. Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations. \* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name © Copyright, 1959-2026, Selected Revisions April 10, 2024. American Society of Health-System Pharmacists®, 4500 East-West Highway, Suite 900, Bethesda, Maryland 20814. The American Society of Health-System Pharmacists, Inc. represents that the database provided hereunder as formulated with a reasonable standard of care, and in conformity with professional standards in liquid sildenafil citrate the field. The American Society of Health-System Pharmacists, Inc. makes no representations or warranties, express or implied, including, but not limited to, any implied warranty or merchantability and/or fitness for a particular purpose, with respect to such database and specifically disclaims all such warranties and representations. Users are advised that decisions regarding drug therapy are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and the database if provided for informational purposes only.
Technical Product Specification Table
The entire monograph for a drug should be reviewed for a throrough understanding of the drug's actions, uses and side effects.
Brand names
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Professional resources
)Tj 0 Tc T* ( )Tj 0.0008 Tc -0.0008 Tw T* [(In another study in healthy m)8.6 (ale volunteers, co)]TJ 0.0009 Tc -0.0009 Tw 18.8 0 Td [(adm)8.7 (i)-1.3 (nistration with the HIV protease inhibitor )]TJ 0.0008 Tc -0.0008 Tw -18.8 -1.165 Td (ritonavir, which is a highly potent P450 inhibito)Tj 0.0004 Tc -0.0004 Tw 19.255 0 Td [(r, at steady state \(500 m)8.2 (g bid\) with VIAGRA )]TJ 0.0008 Tc -0.0008 Tw -19.255 -1.165 Td [(\(100 m)8.6 (g)0.8 ( single dose\) resulted in a 300% \(4-fold\) increase in sildenafil C)]TJ -0.0184 Tc 0 Tw 7.98 0 0 7.98 410.9997 579.1628 Tm [(ma)-18.2 (x)]TJ 0.0005 Tc -0.0005 Tw 12 0 0 12 424.6197 580.6628 Tm ( and a 1000% )Tj 0.0006 Tc -0.0006 Tw -30.115 -1.165 Td [(\(11-fold\) increase in sildenafil plasm)8.4 (a)-0.6 ( AUC. At 24 )]TJ 0.0009 Tc -0.0009 Tw 20.595 0 Td [(hours the plasm)8.7 (a levels of sildenafil were still )]TJ 0.0006 Tc -0.0006 Tw -20.595 -1.165 Td [(approxim)8.4 (a)-0.6 (tely 200 ng/m)8.4 (L)1.4 (, com)8.4 (p)0.6 (ared to approxim)8.4 (a)-0.6 (tely 5 ng/m)8.4 (L)1.4 ( when sildenafil was dosed )]TJ 0.0009 Tc -0.0009 Tw T* [(alone.
Viagra Oral Jelly
The American Society of Health-System Pharmacists, Inc. does not endorse or recommend the use of any drug in the database. The information contained in the database is not a substitute for medical care or treatment by a licensed health care provider. > endobj 296 0 obj <> endobj 294 0 obj <>stream /This label may not be the latest approved by FDA.
- Alcohol can increase the risk of side effects from sildenafil.
- Taking sildenafil does not protect against sexually transmitted infections.
- Patients should inform their doctor of all medications they take.
- Sildenafil may cause a drop in blood pressure in some cases.
For current labeling information, please visit endstream endobj 293 0 obj <> endobj 297 0 obj <> endobj 292 0 obj <>stream /This label may not be the latest approved by FDA.
Is It Safe To Take Cenforce Tablet daily?
[1]Advise patient to inform their clinician of existing or contemplated concomitant therapy, including prescription and OTC drugs and dietary or herbal supplements, as well as any concomitant illnesses. [1]Inform patients of other important precautionary information. Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details. Please refer to the ASHP Drug Shortages Resource Center for information on shortages of one or more of these preparations. \* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name © Copyright, 1959-2026, Selected Revisions April 10, 2024.
Alcohol interaction warning
American Society of Health-System Pharmacists®, 4500 East-West Highway, Suite 900, Bethesda, Maryland 20814. The American Society of Health-System Pharmacists, Inc. represents that the database provided hereunder as formulated with a reasonable standard of care, and in conformity with professional standards in liquid sildenafil citrate the field. The American Society of Health-System Pharmacists, Inc. makes no representations or warranties, express or implied, including, but not limited to, any implied warranty or merchantability and/or fitness for a particular purpose, with respect to such database and specifically disclaims all such warranties and representations.
Is Viagra dosage based on age or weight?
Users are advised that decisions regarding drug therapy are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and the database if provided for informational purposes only. The entire monograph for a drug should be reviewed for a throrough understanding of the drug's actions, uses and side effects. The American Society of Health-System Pharmacists, Inc. does not endorse or recommend the use of any drug in the database. The information contained in the database is not a substitute for medical care or treatment by a licensed health care provider. For current labeling information, please visit endstream endobj 120 0 obj <> endobj 128 0 obj <> endobj 249 0 obj <> endobj 25 0 obj <>/Font<>/ProcSet[/PDF/Text]/XObject<>>>/Rotate 0/Type/Page>> endobj 28 0 obj <>/Font<>/ProcSet[/PDF/Text]/XObject<>>>/Rotate 0/Type/Page>> endobj 31 0 obj <>/Font<>/ProcSet[/PDF/Text]/XObject<>>>/Rotate 0/Type/Page>> endobj 34 0 obj <>/ExtGState<>/Font<>/ProcSet[/PDF/Text]/XObject<>>>/Rotate 0/Type/Page>> endobj 37 0 obj <>/Font<>/ProcSet[/PDF/Text]/XObject<>>>/Rotate 0/Type/Page>> endobj 314 0 obj <>stream q 1 0 0 1 -8.760315 -1.877228 cm 0 0 612 792 re W n 1 0 0 1 8.760315 1.877228 cm BT /GS0 gs /TT0 1 Tf 12 0 0 12 63.2397 47.6228 Tm ( )Tj 19 -0.005 Td (14)Tj 0.0014 Tc -0.0014 Tw -19 54.94 Td [(sildenaf)4.4 (il C)]TJ -0.0184 Tc 0 Tw 7.98 0 0 7.98 118.9797 705.3428 Tm [(ma)-18.2 (x)]TJ 0.0003 Tc -0.0003 Tw 12 0 0 12 132.5997 706.8428 Tm ( and a 210% increase in sildenafil AUC. VIAGRA had no effect on saquinav\ ir )Tj 0.0007 Tc -0.0007 Tw -5.78 -1.165 Td [(pharm)8.5 (acokinetics. Stronger CYP3A4 inhibitors such as ketoconazole or itracona\ zole would be )]TJ 0.0009 Tc -0.0009 Tw 0 -1.165 TD [(expected to have still greater effects, and population data from)8.7 ( patients in clinical trials did )]TJ 0.001 Tc -0.001 Tw T* (indicate a reduction in sildenafil clearance when it )Tj 0.0005 Tc -0.0005 Tw 20.425 0 Td [(was coadm)8.3 (i)-1.7 (nistered with CYP3A4 inhibitors )]TJ 0.0009 Tc -0.0009 Tw -20.425 -1.18 Td [(\(such as ketoconazole, erythrom)8.7 (ycin, or cim)8.7 (etidine\) \(see )]TJ /TT1 1 Tf -0.0011 Tc 0.0011 Tw 22.94 0 Td (DOSAGE AND )Tj -0.0008 Tc 0 Tw -22.94 -1.18 Td (ADMINISTRATION)Tj /TT0 1 Tf 0.001 Tc (\). )Tj 0 Tc T* ( )Tj 0.0008 Tc -0.0008 Tw T* [(In another study in healthy m)8.6 (ale volunteers, co)]TJ 0.0009 Tc -0.0009 Tw 18.8 0 Td [(adm)8.7 (i)-1.3 (nistration with the HIV protease inhibitor )]TJ 0.0008 Tc -0.0008 Tw -18.8 -1.165 Td (ritonavir, which is a highly potent P450 inhibito)Tj 0.0004 Tc -0.0004 Tw 19.255 0 Td [(r, at steady state \(500 m)8.2 (g bid\) with VIAGRA )]TJ 0.0008 Tc -0.0008 Tw -19.255 -1.165 Td [(\(100 m)8.6 (g)0.8 ( single dose\) resulted in a 300% \(4-fold\) increase in sildenafil C)]TJ -0.0184 Tc 0 Tw 7.98 0 0 7.98 410.9997 579.1628 Tm [(ma)-18.2 (x)]TJ 0.0005 Tc -0.0005 Tw 12 0 0 12 424.6197 580.6628 Tm ( and a 1000% )Tj 0.0006 Tc -0.0006 Tw -30.115 -1.165 Td [(\(11-fold\) increase in sildenafil plasm)8.4 (a)-0.6 ( AUC. At 24 )]TJ 0.0009 Tc -0.0009 Tw 20.595 0 Td [(hours the plasm)8.7 (a levels of sildenafil were still )]TJ 0.0006 Tc -0.0006 Tw -20.595 -1.165 Td [(approxim)8.4 (a)-0.6 (tely 200 ng/m)8.4 (L)1.4 (, com)8.4 (p)0.6 (ared to approxim)8.4 (a)-0.6 (tely 5 ng/m)8.4 (L)1.4 ( when sildenafil was dosed )]TJ 0.0009 Tc -0.0009 Tw T* [(alone.