Sildenafil

SILDENAFIL- sildenafil citrate tablet, film coated
Northwind Pharmaceuticals, LLC

1 INDICATIONS & USAGE

Sildenafil tablets are indicated for the treatment of erectile dysfunction.

2 DOSAGE & ADMINISTRATION

2.1 Dosage Information

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

2.2 Use with Food

Sildenafil tablets may be taken with or without food.

2.3 Dosage Adjustments in Specific Situations

Sildenafil tablets were 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 sildenafil tablets are co-administered with an alpha-blocker, patients should be stable on alpha-blocker therapy prior to initiating sildenafil tablets treatment and sildenafil tablets 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 Interactions

Ritonavir
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 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 Inhibitors
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)].

2.5 Dosage Adjustments in Special Populations

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 <30 mL/minute) because administration of sildenafil tablets 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)].

3 DOSAGE FORMS & STRENGTHS

Sildenafil Tablets USP, 25 mg are white colored, round-shaped, biconvex, film coated tablets debossed with ‘I’ on one side and ’35’ on the other side.
Sildenafil Tablets USP, 50 mg are white colored, round-shaped, biconvex, film coated tablets debossed with ‘I’ on one side and ’36’ on the other side.
Sildenafil Tablets USP, 100 mg are white colored, round-shaped, biconvex, film coated tablets debossed with ‘I’ on one side and ’58’ on the other side.

4 CONTRAINDICATIONS

4.1 Nitrates

Consistent with its known effects on the nitric oxide/cGMP pathway [see Clinical Pharmacology ( 12.1, 12.2)] ,sildenafil tablets were 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 sildenafil tablets, 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 Reactions

Sildenafil tablets are contraindicated in patients with a known hypersensitivity to sildenafil, as contained in sildenafil tablets 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 sildenafil tablets in patients who are using a GC stimulator, such as riociguat. PDE5 inhibitors, including sildenafil tablets, may potentiate the hypotensive effects of GC stimulators.

5 WARNINGS AND PRECAUTIONS

5.1 Cardiovascular

There is a potential for cardiac risk of sexual activity in patients with preexisting cardiovascular disease. Therefore, treatments for erectile dysfunction, including sildenafil tablets, 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.
Sildenafil tablets have 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 sildenafil tablets, 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 sildenafil tablets – 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 sildenafil tablets 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 Priapism

Prolonged erection greater than 4 hours and priapism (painful erections greater than 6 hours in duration) have been reported infrequently since market approval of sildenafil tablets. 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.
Sildenafil tablets 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 sildenafil tablets in patients with sickle cell or related anemias.