14 CLINICAL STUDIES

Concomitant use of any form of organic nitrate

The Medically Approved Combination – A Sublingual Option

[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 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. (e.g., nitroglycerin), including recreational

use of inhaled nitrites (amyl

5.7 Priapism

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. nitrate or nitrite, ''poppers''), with sildenafil is contraindicated

due to the potential

• Sildenafil 10mg is available by prescription only.
• Do not exceed the recommended dose to prevent adverse effects.
• Alcohol consumption can increase side effects of sildenafil.
• Sildenafil 10mg may interact with certain medications.
• Patients with heart issues should consult a doctor before use.

pharmacodynamic interaction (increased hypotensive effect).

Further information

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

Cardiology (ACC) and American Heart Association

8.7 Patients with Renal Impairment

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.

Improves quality of life

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). (AHA) recognize that use of organic nitrates and nitrites in patients

receiving sildenafil may not be

Before Using

[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. [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 sildenafil 100mg lowest price its active metabolite are present in human milk.

Reduces progression of erectile dysfunction

[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. 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. completely avoidable, provided sufficient time has

Comparing Side Effects

[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). [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.

Other Interactions

[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. 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. elapsed between use of sildenafil and

• The medication can be part of a treatment plan for ED.
• Do not share sildenafil with others, even if they have similar symptoms.
• Taking sildenafil on an empty stomach may increase effectiveness.
• Be aware of possible allergic reactions, such as rash.
• Follow-up with your healthcare provider regularly when using sildenafil.

administration of the nitrate or nitrite.

5.5 Hearing Loss

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.

What should I know about sildenafil before taking it?

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.