Sildenafil 20mg Tablets

Although at greater risk for NAION compared to the general population, evidence is insufficient to support screening for "crowded" optic disc in prospective users of PDE type 5 inhibitors for the treatment of ED. Sildenafil should be used with caution in patients with retinitis pigmentosa, a retinal disorder that may be accompanied by a genetic disorder of retinal phosphodiesterases in some patients, since data establishing the safety and efficacy of the drug in these patients currently are lacking. Sudden decrease or loss of hearing, with or without concomitant vestibular manifestations (e.g., tinnitus, dizziness), has been reported in temporal association with use of PDE type 5 inhibitors, including sildenafil. [1] It is unclear whether these otic effects are directly related to PDE type 5 inhibitors or attributed to other underlying risk factors for hearing loss, a combination of these factors, or to other factors. Patients should discontinue sildenafil and seek medical attention immediately if sudden hearing loss or decreased hearing occurs. Prolonged erection (exceeding 4 hours) and priapism (painful erection exceeding 6 hours) have been reported infrequently during postmarketing surveillance with sildenafil. [1][31][127][131][139][146][147] Because of the risk of penile tissue damage and permanent loss of potency if priapism is not treated immediately, patients should be warned to seek immediate medical attention if an erection persists for longer than 4 hours.

Comparing the Mechanism of Action

Although at greater risk for NAION compared to the general population, evidence is insufficient to support screening for "crowded" optic disc in prospective users of PDE type 5 inhibitors for the treatment of ED. Sildenafil should be used with caution in patients with retinitis pigmentosa, a retinal disorder that may be accompanied by a genetic disorder of retinal phosphodiesterases in some patients, since data establishing the safety and efficacy of the drug in these patients currently are lacking. Sudden decrease or loss of hearing, with or without concomitant vestibular manifestations (e.g., tinnitus, dizziness), has been reported in temporal association with use of PDE type 5 inhibitors, including sildenafil. [1] It is unclear whether these otic effects are directly related to PDE type 5 inhibitors or attributed to other underlying risk factors for hearing loss, a combination of these factors, or to other factors. Patients should discontinue sildenafil and seek medical attention immediately if sudden hearing loss or decreased hearing occurs.

Alcohol interaction warning

Prolonged erection (exceeding 4 hours) and priapism (painful erection exceeding 6 hours) have been reported infrequently during postmarketing surveillance with sildenafil. [1][31][127][131][139][146][147] Because of the risk of penile tissue damage and permanent loss of potency if priapism is not treated immediately, patients should be warned to seek immediate medical attention if an erection persists for longer than 4 hours. Sildenafil should be used with caution in patients with anatomic deformation of the penis (such as angulation, cavernosal fibrosis, or Peyronie's disease) and in patients who have conditions that may predispose them to priapism (e.g., sickle cell anemia, multiple myeloma, leukemia). Caution is advised when PDE type 5 inhibitors are co-administered with α-adrenergic blocking agents; blood pressure may be lowered significantly and in some patients, symptomatic hypotension (e.g., dizziness, lightheadedness, fainting) may occur. [1] Patients who demonstrate hemodynamic instability during therapy with an α-adrenergic blocking agent alone are at increased risk for symptomatic hypotension with concomitant use of a PDE type 5 inhibitor.

6.2 Postmarketing Experience

In patients who exhibit hemodynamic instability while receiving an α-adrenergic blocking agent, use caution. [1] Patients should be stable on an α-adrenergic blocking agent prior to initiation of sildenafil, and sildenafil should be administered at the lowest possible dose. [1] In patients receiving an optimal dose of sildenafil, initiate the α-adrenergic blocking agent at the lowest dose. Concomitant administration of ritonavir substantially increases serum concentrations of sildenafil (11-fold increase in AUC). [1] Data are limited; decreased blood pressure, syncope, and prolonged erection have been reported in some healthy volunteers exposed to high doses of sildenafil (200-800 mg). Sildenafil should be used with caution in patients with anatomic deformation of the penis (such as angulation, cavernosal fibrosis, or Peyronie's disease) and in patients who have conditions that may predispose them to priapism (e.g., sickle cell anemia, multiple myeloma, leukemia). Caution is advised when PDE type 5 inhibitors are co-administered with α-adrenergic blocking agents; blood pressure may be lowered significantly and in some patients, symptomatic hypotension (e.g., dizziness, lightheadedness, fainting) may occur. [1] Patients who demonstrate hemodynamic instability during therapy with an α-adrenergic blocking agent alone are at increased risk for symptomatic hypotension with concomitant use of a PDE type 5 inhibitor.

In patients who exhibit hemodynamic instability while receiving an α-adrenergic blocking agent, use caution. [1] Patients should be stable on an α-adrenergic blocking agent prior to initiation of sildenafil, and sildenafil should be administered at the lowest possible dose. [1] In patients receiving an optimal dose of sildenafil, initiate the α-adrenergic blocking agent at the lowest dose. Concomitant administration of ritonavir substantially increases serum concentrations of sildenafil (11-fold increase in AUC).

10. Overdosage

[1] Use sildenafil with caution in patients receiving ritonavir; reduced sildenafil dosage is recommended to decrease the chance of adverse reactions to sildenafil. Bleeding events have been reported in patients taking sildenafil for ED. [1] In patients with bleeding disorders or active peptic ulcers, sildenafil should be used with caution since safety of the drug has not been established. [1][27][33][67][131] The possibility that sildenafil could potentiate the effects of certain other drugs exhibiting antiplatelet activity should be considered. Safety and efficacy have not been established for use of sildenafil in combination with other PDE type 5 inhibitors or other treatments for ED; such combinations may further lower blood pressure and are not recommended.

Sildenafil may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

Patients should be advised that use of sildenafil provides no protection against sexually transmitted diseases and they should be counseled regarding protective measures to guard against such transmission. Sildenafil for ED (e.g., Viagra®) is not indicated for use in females. [1] There are no data with use in pregnant women to inform any drug-associated risks for adverse developmental outcomes. No evidence of teratogenicity, embryotoxicity, or fetotoxicity was observed in rats and rabbits receiving up to 200 mg/kg daily of sildenafil during organogenesis. [1] These doses in rats and rabbits represent about 16 and 32 times, respectively, the maximum recommended human dose (MRHD) for the treatment of ED on a mg/m2 basis in a 50-kg patient.

Vybrique Oral Film

[1] No adverse effects were observed Iin a prenatal and postnatal development study in rats receiving 30 mg/kg daily for 36 days (equivalent to 2-times the MRHD on a mg/m2 basis in a 50-kg subject). [1] Limited data indicate that sildenafil and its active metabolite are present in sildenafil citrates human milk. [1] There is no information about the effects of sildenafil on the breastfed infant or on milk production. Reproduction studies revealed no evidence of impaired fertility at sildenafil dosages up to 60 mg/kg daily (for 36 days in female rats and 102 days in male rats), a dosage representing more than 25 times the human male AUC. [1] No effect on sperm motility or morphology was noted after a single 100-mg oral sildenafil dose in healthy human adults. [1] Data are limited; decreased blood pressure, syncope, and prolonged erection have been reported in some healthy volunteers exposed to high doses of sildenafil (200-800 mg). [1] Use sildenafil with caution in patients receiving ritonavir; reduced sildenafil dosage is recommended to decrease the chance of adverse reactions to sildenafil. Bleeding events have been reported in patients taking sildenafil for ED. [1] In patients with bleeding disorders or active peptic ulcers, sildenafil should be used with caution since safety of the drug has not been established. [1][27][33][67][131] The possibility that sildenafil could potentiate the effects of certain other drugs exhibiting antiplatelet activity should be considered.

How does Sildenafil Work for Erectile Dysfunction?

Safety and efficacy have not been established for use of sildenafil in combination with other PDE type 5 inhibitors or other treatments for ED; such combinations may further lower blood pressure and are not recommended. Patients should be advised that use of sildenafil provides no protection against sexually transmitted diseases and they should be counseled regarding protective measures to guard against such transmission. Sildenafil for ED (e.g., Viagra®) is not indicated for use in females. [1] There are no data with use in pregnant women to inform any drug-associated risks for adverse developmental outcomes.

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility

The possibility that any drug that inhibits CYP3A4 may interact with sildenafil should be considered. [1][67] In some cases, a reduction in sildenafil dosage is recommended. Clinically important pharmacokinetic interactions have been reported with several antiretroviral agents that inhibit CYP3A4 (e.g., ritonavir, saquinavir) and can potentially result in an increase in sildenafil-associated adverse effects. The possibility that any drug that induces CYP3A4 may interact with sildenafil should be considered. Pharmacokinetic data from patients in clinical trials showed no effect on sildenafil pharmacokinetics when the drug was used concomitantly with CYP2D6 inhibitors such as selective serotonin-reuptake inhibitors (SSRIs) or tricyclic antidepressants.

Take it on an empty stomach

[1] [26][67] At clinically relevant concentrations, the manufacturer states that it is unlikely that sildenafil will alter the clearance of drugs metabolized by these isoenzymes. A minor route of metabolism of sildenafil is through the CYP2C9 isoenzyme. [1][67][250] Although some clinicians state that the possibility of an interaction between sildenafil and drugs metabolized by CYP2C9 should be considered, there was no evidence of appreciable inhibition of CYP2C9-mediated (e.g., tolbutamide, warfarin) or CYP3A4-mediated (e.g., ritonavir, saquinavir) metabolism by sildenafil in clinical studies. **Antacids:**Single doses of an aluminum and magnesium hydroxide-containing antacid did not affect the oral bioavailability of sildenafil. Cimetidine: Plasma sildenafil concentrations increased by approximately 56% in healthy individuals who received a single 50-mg oral dose of the drug concomitantly with a single oral dose of cimetidine (800 mg), a nonspecific inhibitor of the cytochrome P-450 mixed-function oxidase system.

What’s the difference between sildenafil 50 mg and 100 mg?

[1][67] Population pharmacokinetic analysis of data from clinical trials indicates that cimetidine reduces sildenafil clearance when these drugs are administered concomitantly. [1][139] Some clinicians recommend that a lower initial sildenafil dose (25 mg) be considered in patients with ED receiving cimetidine. No evidence of teratogenicity, embryotoxicity, or fetotoxicity was observed in rats and rabbits receiving up to 200 mg/kg daily of sildenafil during organogenesis. [1] These doses in rats and rabbits represent about 16 and 32 times, respectively, the maximum recommended human dose (MRHD) for the treatment of ED on a mg/m2 basis in a 50-kg patient. [1] No adverse effects were observed Iin a prenatal and postnatal development study in rats receiving 30 mg/kg daily for 36 days (equivalent to 2-times the MRHD on a mg/m2 basis in a 50-kg subject). [1] Limited data indicate that sildenafil and its active metabolite are present in sildenafil citrates human milk. [1] There is no information about the effects of sildenafil on the breastfed infant or on milk production.

• Sildenafil 20 mg is a prescription medication used for erectile dysfunction.
• It helps increase blood flow to the penis during sexual activity.
• Typically prescribed for men with ED to improve sexual performance.

Reproduction studies revealed no evidence of impaired fertility at sildenafil dosages up to 60 mg/kg daily (for 36 days in female rats and 102 days in male rats), a dosage representing more than 25 times the human male AUC. [1] No effect on sperm motility or morphology was noted after a single 100-mg oral sildenafil dose in healthy human adults. Sildenafil for ED (e.g., Viagra®) is not indicated for use in pediatric patients.

Brand names

Sildenafil for ED (e.g., Viagra®) is not indicated for use in pediatric patients. [1] The manufacturer states that safety and efficacy of sildenafil in children have not been established. The AUC of free (unbound) sildenafil and its active N-desmethyl metabolite were 45 and 57% higher, respectively, in healthy volunteers >=65 years of age compared to healthy volunteers 18-45 years of age. [1] Clinical studies included patients >=65 years of age (18%) and >=75 years of age (2%); no overall differences in safety and efficacy were observed between older (>=65 years of age) and younger (<65 years of age) patients[1] Because higher plasma levels may increase the incidence of adverse reactions, consider reducing the initial sildenafil dosage to 25 mg in older patients. In patients with hepatic cirrhosis (Child-Pugh class A or B), sildenafil clearance is reduced, resulting in increased AUC (by 85%) and peak plasma concentrations (by 47%) compared with values observed in age-matched healthy adults.

Patient resources

[1][31][131] The effect of severe hepatic impairment on the pharmacokinetics of sildenafil has not been evaluated to date. In patients with any degree of hepatic impairment (e.g. cirrhosis), consider reducing the initial dose of sildenafil to 25 mg.[1] In patients with mild (creatinine clearance 50-80 mL/minute) or moderate (creatinine clearance 30-49 mL/minute) renal impairment, the pharmacokinetics of a single 50-mg oral dose of sildenafil are not altered. [1][31][131] However, in patients with severe (creatinine clearance less than 30 mL/minute) renal impairment, sildenafil clearance is reduced, resulting in AUC and peak plasma concentrations of the parent drug that are approximately double those in age-matched healthy adults. [1][31][67][131] In addition, AUC and peak plasma concentrations of the N-demethylated metabolite are 200 and 79% greater, respectively, than those in individuals with normal renal function.

Professional resources

In patients with severe renal impairment (creatinine clearance less than 30 mL/minute), consider reducing the initial dose of sildenafil to 25 mg.[1] The most common adverse effects (>=2%) of sildenafil used for the treatment of ED include headache, flushing, dyspepsia, abnormal vision, nasal congestion, back pain, myalgia, nausea, dizziness, and rash. Sildenafil is metabolized principally via hepatic cytochrome P-450 (CYP) microsomal isoenzymes 3A4 (major route) and 2C9 (minor route). [1][91][131] Inhibitors and inducers of these isoenzymes may reduce or increase sildenafil clearance, respectively. In vitro studies indicate that sildenafil is a weak inhibitor of the CYP isoenzymes 1A2, 2C9, 2C19, 2D6, 2E1, and 3A4. [1][26][67][250] Sildenafil is not expected to affect the pharmacokinetics of substrates of these CYP enzymes at clinically relevant concentrations. [1] The manufacturer states that safety and efficacy of sildenafil in children have not been established.

• Sildenafil 20 mg tablets should be taken about 30 to 60 minutes before sexual activity.
• It’s important not to take more than one dose in 24 hours.
• Do not crush or chew the medication; swallow it whole with water.

The AUC of free (unbound) sildenafil and its active N-desmethyl metabolite were 45 and 57% higher, respectively, in healthy volunteers >=65 years of age compared to healthy volunteers 18-45 years of age. [1] Clinical studies included patients >=65 years of age (18%) and >=75 years of age (2%); no overall differences in safety and efficacy were observed between older (>=65 years of age) and younger (<65 years of age) patients[1] Because higher plasma levels may increase the incidence of adverse reactions, consider reducing the initial sildenafil dosage to 25 mg in older patients. In patients with hepatic cirrhosis (Child-Pugh class A or B), sildenafil clearance is reduced, resulting in increased AUC (by 85%) and peak plasma concentrations (by 47%) compared with values observed in age-matched healthy adults. [1][31][131] The effect of severe hepatic impairment on the pharmacokinetics of sildenafil has not been evaluated to date. In patients with any degree of hepatic impairment (e.g. cirrhosis), consider reducing the initial dose of sildenafil to 25 mg.[1] In patients with mild (creatinine clearance 50-80 mL/minute) or moderate (creatinine clearance 30-49 mL/minute) renal impairment, the pharmacokinetics of a single 50-mg oral dose of sildenafil are not altered. [1][31][131] However, in patients with severe (creatinine clearance less than 30 mL/minute) renal impairment, sildenafil clearance is reduced, resulting in AUC and peak plasma concentrations of the parent drug that are approximately double those in age-matched healthy adults. [1][31][67][131] In addition, AUC and peak plasma concentrations of the N-demethylated metabolite are 200 and 79% greater, respectively, than those in individuals with normal renal function. In patients with severe renal impairment (creatinine clearance less than 30 mL/minute), consider reducing the initial dose of sildenafil to 25 mg.[1] The most common adverse effects (>=2%) of sildenafil used for the treatment of ED include headache, flushing, dyspepsia, abnormal vision, nasal congestion, back pain, myalgia, nausea, dizziness, and rash. Sildenafil is metabolized principally via hepatic cytochrome P-450 (CYP) microsomal isoenzymes 3A4 (major route) and 2C9 (minor route). [1][91][131] Inhibitors and inducers of these isoenzymes may reduce or increase sildenafil clearance, respectively. In vitro studies indicate that sildenafil is a weak inhibitor of the CYP isoenzymes 1A2, 2C9, 2C19, 2D6, 2E1, and 3A4. [1][26][67][250] Sildenafil is not expected to affect the pharmacokinetics of substrates of these CYP enzymes at clinically relevant concentrations.

• The usual starting dose of sildenafil for ED is 50 mg, but 20 mg may be prescribed for some patients.
• Prescription requirements ensure safe usage and proper dosing based on health conditions.
• Always follow a doctor’s instructions when taking sildenafil 20 mg.

The possibility that any drug that inhibits CYP3A4 may interact with sildenafil should be considered. [1][67] In some cases, a reduction in sildenafil dosage is recommended. Clinically important pharmacokinetic interactions have been reported with several antiretroviral agents that inhibit CYP3A4 (e.g., ritonavir, saquinavir) and can potentially result in an increase in sildenafil-associated adverse effects. The possibility that any drug that induces CYP3A4 may interact with sildenafil should be considered. Pharmacokinetic data from patients in clinical trials showed no effect on sildenafil pharmacokinetics when the drug was used concomitantly with CYP2D6 inhibitors such as selective serotonin-reuptake inhibitors (SSRIs) or tricyclic antidepressants. [1] [26][67] At clinically relevant concentrations, the manufacturer states that it is unlikely that sildenafil will alter the clearance of drugs metabolized by these isoenzymes. A minor route of metabolism of sildenafil is through the CYP2C9 isoenzyme. [1][67][250] Although some clinicians state that the possibility of an interaction between sildenafil and drugs metabolized by CYP2C9 should be considered, there was no evidence of appreciable inhibition of CYP2C9-mediated (e.g., tolbutamide, warfarin) or CYP3A4-mediated (e.g., ritonavir, saquinavir) metabolism by sildenafil in clinical studies. **Antacids:**Single doses of an aluminum and magnesium hydroxide-containing antacid did not affect the oral bioavailability of sildenafil. Cimetidine: Plasma sildenafil concentrations increased by approximately 56% in healthy individuals who received a single 50-mg oral dose of the drug concomitantly with a single oral dose of cimetidine (800 mg), a nonspecific inhibitor of the cytochrome P-450 mixed-function oxidase system. [1][67] Population pharmacokinetic analysis of data from clinical trials indicates that cimetidine reduces sildenafil clearance when these drugs are administered concomitantly.

2.1 Sildenafil Tablets

[1][139] Some clinicians recommend that a lower initial sildenafil dose (25 mg) be considered in patients with ED receiving cimetidine.