SILDENAFIL- sildenafil citrate tablet
1 INDICATIONS AND USAGE
Sildenafil tablets are indicated for the treatment of pulmonary arterial hypertension (WHO Group I) in adults to improve exercise ability and delay clinical worsening. The delay in clinical worsening was demonstrated when sildenafil tablets were added to background epoprostenol therapy [see Clinical Studies (14)].
Studies establishing effectiveness were short-term (12 to 16 weeks), and included predominately patients with New York Heart Association (NYHA) Functional Class II-III symptoms and idiopathic etiology (71%) or associated with connective tissue disease (CTD) (25%).
2 DOSAGE AND ADMINISTRATION
2.1 Sildenafil Tablets
The recommended dose of sildenafil tablets is 20 mg three times a day. Administer sildenafil tablet doses 4 to 6 hours apart.
In the clinical trial no greater efficacy was achieved with the use of higher doses. Treatment with doses higher than 20 mg three times a day is not recommended.
3 DOSAGE FORMS AND STRENGTHS
Sildenafil tablets are supplied as white to off-white, round shaped, film-coated tablets with debossing 'AN 351" on one side and plain on the other side, containing sildenafil citrate, USP equivalent to 20 mg of sildenafil.
Sildenafil tablets are contraindicated in patients with:
Concomitant use of organic nitrates in any form, either regularly or intermittently, because of the greater risk of hypotension [see Warnings and Precautions (5.2)].
Known hypersensitivity to sildenafil or any component of the tablet. Hypersensitivity, including anaphylactic reaction, anaphylactic shock and anaphylactoid reaction, has been reported in association with the use of sildenafil.
5 WARNINGS AND PRECAUTIONS
5.1 Mortality with Pediatric Use
In a long-term trial in pediatric patients with PAH, an increase in mortality with increasing sildenafil citrate dose was observed. Deaths were first observed after about 1 year and causes of death were typical of patients with PAH. Use of sildenafil citrate, particularly chronic use, is not recommended in children [see Use in Specific Populations (8.4)].
Sildenafil citrate has vasodilatory properties, resulting in mild and transient decreases in blood pressure. Before prescribing sildenafil citrate, carefully consider whether patients with certain underlying conditions could be adversely affected by such vasodilatory effects (e.g., patients on antihypertensive therapy or with resting hypotension [BP less than 90/50], fluid depletion, severe left ventricular outflow obstruction, or autonomic dysfunction). Monitor blood pressure when co-administering blood pressure lowering drugs with sildenafil citrate.
5.3 Worsening Pulmonary Vascular Occlusive Disease
Pulmonary vasodilators may significantly worsen the cardiovascular status of patients with pulmonary veno-occlusive disease (PVOD). Since there are no clinical data on administration of sildenafil citrate to patients with veno-occlusive disease, administration of sildenafil citrate to such patients is not recommended. Should signs of pulmonary edema occur when sildenafil citrate is administered, consider the possibility of associated PVOD.
The incidence of epistaxis was 13% in patients taking sildenafil citrate with PAH secondary to CTD. This effect was not seen in idiopathic PAH (sildenafil citrate 3%, placebo 2%) patients. The incidence of epistaxis was also higher in sildenafil citrate-treated patients with a concomitant oral vitamin K antagonist (9% versus 2% in those not treated with concomitant vitamin K antagonist).
The safety of sildenafil citrate is unknown in patients with bleeding disorders or active peptic ulceration.
5.5 Visual Loss
When used to treat erectile dysfunction, non-arteritic anterior ischemic optic neuropathy (NAION), a cause of decreased vision including permanent loss of vision, has been reported postmarketing in temporal association with the use of phosphodiesterase type 5 (PDE-5) inhibitors, including sildenafil. Most, but not all, of these patients had underlying anatomic or vascular risk factors for developing NAION, including but not necessarily limited to: low cup to disc ratio ("crowded disc"), age over 50, diabetes, hypertension, coronary artery disease, hyperlipidemia and smoking. Based on published literature, the annual incidence of NAION is 2.5 to 11.8 cases per 100,000 males aged ? 50 per year in the general population. An observational study evaluated whether recent, episodic use of PDE5 inhibitors (as a class), typical of erectile dysfunction treatment, was associated with acute onset of NAION. The results suggest an approximately 2-fold increase in the risk of NAION within 5 half-lives of PDE5 inhibitor use. It is not possible to determine whether these events are related directly to the use of PDE-5 inhibitors, to the patient's underlying vascular risk factors or anatomical defects, to a combination of these factors, or to other factors.
Advise patients to seek immediate medical attention in the event of a sudden loss of vision in one or both eyes while taking PDE-5 inhibitors, including sildenafil citrate. Physicians should also discuss the increased risk of NAION with patients who have already experienced NAION in one eye, including whether such individuals could be adversely affected by use of vasodilators, such as PDE-5 inhibitors.
There are no controlled clinical data on the safety or efficacy of sildenafil citrate in patients with retinitis pigmentosa, a minority whom have genetic disorders of retinal phosphodiesterases. Prescribe sildenafil citrate with caution in these patients.
5.6 Hearing Loss
Cases of sudden decrease or loss of hearing, which may be accompanied by tinnitus and dizziness, have been reported in temporal association with the use of PDE-5 inhibitors, including sildenafil citrate. In some of the cases, medical conditions and other factors were reported that may have played a role. In many cases, medical follow-up information was limited. It is not possible to determine whether these reported events are related directly to the use of sildenafil citrate, to the patient's underlying risk factors for hearing loss, a combination of these factors, or to other factors.
Advise patients to seek prompt medical attention in the event of sudden decrease or loss of hearing while taking PDE-5 inhibitors, including sildenafil citrate.
5.7 Combination with other PDE-5 inhibitors
Sildenafil is also marketed as VIAGRA�. The safety and efficacy of combinations of sildenafil citrate with VIAGRA or other PDE-5 inhibitors have not been studied. Inform patients taking sildenafil citrate not to take VIAGRA or other PDE-5 inhibitors.
Use sildenafil citrate with caution in patients with anatomical deformation of the penis (e.g., angulation, cavernosal fibrosis, or Peyronie's disease) or in patients who have conditions, which may predispose them to priapism (e.g., sickle cell anemia, multiple myeloma, or leukemia). In the event of an erection that persists longer than 4 hours, the patient should seek immediate medical assistance. If priapism (painful erection greater than 6 hours in duration) is not treated immediately, penile tissue damage and permanent loss of potency could result.
5.9 Vaso-occlusive Crisis in Patients with Pulmonary Hypertension Secondary to Sickle Cell Anemia
In a small, prematurely terminated study of patients with pulmonary hypertension (PH) secondary to sickle cell disease, vaso-occlusive crises requiring hospitalization were more commonly reported by patients who received sildenafil citrate than by those randomized to placebo. The effectiveness and safety of sildenafil citrate in the treatment of PAH secondary to sickle cell anemia has not been established.
6 ADVERSE REACTIONS
The following serious adverse events are discussed elsewhere in the labeling:
Mortality with pediatric use [see Warnings and Precautions (5.1) and Use in Specific Populations (8.4)]
Hypotension [see Warnings and Precautions (5.2)]
Vision loss [see Warnings and Precautions (5.5)]
Hearing loss [see Warnings and Precautions (5.6)]
Priapism [see Warnings and Precautions (5.8)]
Vaso-occlusive crisis [see Warnings and Precautions (5.9)]
Sildenafil citrate, USP, phosphodiesterase-5 (PDE-5) inhibitor, is the citrate salt of sildenafil, a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type-5 (PDE-5). Sildenafil is also marketed as VIAGRA� for erectile dysfunction.
Sildenafil citrate, USP is designated chemically as 1-[[3-(6,7-dihydro-1-methyl-7-oxo-3-propyl-1H -pyrazolo [4,3-d ] pyrimidin-5-yl)-4-ethoxyphenyl] sulfonyl]-4-methylpiperazine citrate
Sildenafil citrate, USP is a white to off-white crystalline powder with a solubility of 3.5 mg/mL in water and a molecular weight of 666.7.
Sildenafil Tablets: Sildenafil tablets are formulated as white to off-white, round shaped film-coated tablets for oral administration. Each tablet contains sildenafil citrate, USP equivalent to 20 mg of sildenafil. In addition to the active ingredient, sildenafil citrate, USP, each tablet contains the following inactive ingredients: croscarmellose sodium, dibasic calcium phosphate anhydrous, hypromellose, magnesium stearate, microcrystalline cellulose, polyethylene glycol, polyvinyl alcohol, talc and titanium dioxide.
12 CLINICAL PHARMACOLOGY
12.1 Mechanism of Action
Sildenafil is an inhibitor of cGMP specific phosphodiesterase type-5 (PDE-5) in the smooth muscle of the pulmonary vasculature, where PDE-5 is responsible for degradation of cGMP. Sildenafil, therefore, increases cGMP within pulmonary vascular smooth muscle cells resulting in relaxation. In patients with PAH, this can lead to vasodilation of the pulmonary vascular bed and, to a lesser degree, vasodilatation in the systemic circulation.
PATIENT COUNSELING INFORMATION
See FDA-approved patient labeling (Patient Information).
Inform patients of contraindication of sildenafil citrate with regular and/or intermittent use of organic nitrates.
Inform patients that sildenafil is also marketed as VIAGRA for erectile dysfunction. Advise patients taking sildenafil citrate not to take VIAGRA or other PDE-5 inhibitors.
Advise patients to seek immediate medical attention for a sudden loss of vision in one or both eyes while taking sildenafil citrate. Such an event may be a sign of NAION.
Advise patients to seek prompt medical attention in the event of sudden decrease or loss of hearing while taking sildenafil citrate. These events may be accompanied by tinnitus and dizziness.
This product's label may have been updated. For current full prescribing information, please visit www.amneal.com