Sildenafil - Warnings and Precautions

5 WARNINGS AND PRECAUTIONS Patients should not use sildenafil tablets if sexual activity is inadvisable due to cardiovascular status Patients should seek emergency treatment if an erection lasts >4 hours.

Use sildenafil tablets with caution in patients predisposed to priapism Patients should stop sildenafil tablets 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).

Sildenafil tablets should be used with caution, and only when the anticipated benefits outweigh the risks, in patients with a history of NAION.

Patients with a “crowded” optic disc may also be at an increased risk of NAION.

Patients should stop sildenafil tablets and seek prompt medical attention in the event of sudden decrease or loss of hearing Caution is advised when sildenafil tablets is co-administered with alpha-blockers or anti-hypertensives.

Concomitant use may lead to hypotension Decreased blood pressure, syncope, and prolonged erection may occur at higher sildenafil citrate exposures.

In patients taking strong CYP inhibitors, such as ritonavir, sildenafil exposure is increased.

Decrease in sildenafil citrate dosage is recommended ( 2.4 , 5.6 ) 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 citrate has 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 ].

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 citrate - 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.

5.3 Effects on the Eye Physicians should advise patients to stop use of all phosphodiesterase type 5 (PDE5) inhibitors, including sildenafil tablets, and seek medical attention in the event of a sudden loss of vision in one or both eyes.

Such an event may be a sign of non-arteritic anterior ischemic optic neuropathy (NAION), a rare condition and a cause of decreased vision including permanent loss of vision, that has been reported rarely post-marketing in temporal association with the use of all PDE5 inhibitors.

Based on published literature, the annual incidence of NAION is 2.5-11.8 cases per 100,000 in males aged ≥ 50.

An observational case-crossover study evaluated the risk of NAION when PDE5 inhibitor use, as a class, occurred immediately before NAION onset (within 5 half-lives), compared to PDE5 inhibitor use in a prior time period.

The results suggest an approximate 2-fold increase in the risk of NAION, with a risk estimate of 2.15 (95% CI 1.06, 4.34).

A similar study reported a consistent result, with a risk estimate of 2.27 (95% CI 0.99, 5.20).