Rx SILDENAFIL CITRATE TABLETS
NCI Sildenafil Tablets 100 mg phosphodiesterase-5 (PDE5) inhibitor indicated for the treatment of erectile dysfunction (ED)
Each film-coated tablet contains:
Sildenafil citrate equivalent to Sildenafil 100mg
Colour: Indigo Carmine
Sildenafil tablets 100mg is a selective inhibitor of cyclic guanosine monophosphate specific-phosphodiesterase type 5 (PDE-5) enzyme. The physiologic mechanism of erection of the penis involves the release of nitric oxide “NO” in the human corpus cavernosum during sexual stimulation. “NO” activates the enzyme guanylate cyclase, which results in increased levels of cyclic guanosine monophosphate (c-gmp) producing smooth muscle relaxation and increased blood flow. In the absence of sexual stimulation, Sildenafil is not effective when administered at its therapeutic doses.
Sildenafil tablets 100 mg is mainly indicated for patients with a failure to achieve erection during sexual intercourse.
Following the oral administration in healthy male volunteers, Sildenafil is rapidly absorbed with an absolute bioavailability of about 40% Peak plasma concentrations are attained within 30 to 120 minutes of oral dosing in the fasting state. Both sildenafil and its metabolites are actively bound to the proteins (96%) and have terminal half lives (T1/2) of about 4 hours. The elimination is mainly in the form of faeces and to a lesser extent in the urine.
NCI Sildenafil tablets 100 mg is contraindicated in patients with a known hypersensitivity on sildenafil or any one of the tablet components. There are no adequate and well controlled studies of sildenafil pregnant and lactating women and in paediatric patients.
– Administration of NCI Sildenafil Tablets 100 mg to patients using Nitric oxide donors; such as organic nitrates or organic nitrites in any form. Sildenafil was shown to potentiate the hypotensive effect of nitrates.
– Known hypersensitivity to sildenafil or any component of the tablet.
– NCI Sildenafil Tablets 100 mg is not indicated for use in women. There are no adequate and well controlled studies of sildenafil in pregnant women.
– NCI Sildenafil Tablets 100 mg is not indicated for use in paediatric patients. Safety and effectiveness have not been established in paediatric patients.
NCI Sildenafil should be administered with caution in patients with pre-existing cardiovascular diseases such as myocardial infarction, stroke or life-threatening arrhythmias, patients with a brief history of blood pressure complications, patients with unstable angina, cardiac failure and patients with retinitis pigmentosa.
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.
Patients should stop using NCI Sildenafil tablets 100 mg and seek medical care if a sudden loss of vision occurs in one or both eyes which could be sign of non arteretic anterior ischemic optic neuropathy (NAION). NCI Sildenafil Tablets 100 mg should be used with caution and only when 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 NCI Sildenafil Tablets 100 mg and seek prompt medical attention in the event of sudden decrease or loss of hearing. Decreased blood pressure, syncope and prolonged erection may occur at higher sildenafil exposures. In patients taking strong CYP Inhibitors such as ritonavir, Sildenafil exposure is increased. Decrease in Sildenafil is recommended. Recommended dose for ritonavir – treated patients is 25mg prior to sexual activity and the recommended maximum dose is 25 mg within 48 hrs period because concomitant administration increased the blood levels of sildenafil by 11-fold. Consider starting dose of 25mg in patients treated with Erythromycin or strong CYP3A4 Inhibitors (e.g. Ketoconazole itracorrazole, saquinavir) Clinical data have shown that co-administration with saquinavir or erythromycin increased pIasma level of Sildenafil by about 3-fold.
In geriatic patients (age group 65 years and above) with a history of hepatic and renal impairment. Oral administration resulted in reduced clearance of sildenafil. In such subjects, starting dose of 25 mg is recommended as higher plasma levels may increase both the efficacy and incidence of adverse effects.
The following adverse effects were reported on oral administration: headache, flushing, respiratory tract infection, angina pectoris, AV block, syncope, tachycardia, paresthesia, tremor, depression, oesophagitis, rectal hemorrhage, liver function tests, hypoglycemia, retinal vascular disease, photosensitivity, temporary vision loss/decreased vision, ocular, redness, swelling, vitreous detachment/traction, increased intraocular pressure.
Concurrent administration with cytochrome P450 inhibitors resulted in reduced sildenafil clearance in hypertensive subjects, concurrent administration of Sildenafil and calcium channel blocker such as amlodipine (5mg and 10mg) resulted in as additional blood pressure reduction of both systolic and diastolic types. Oral administration of HIV protease inhibitor-ritonavir caused a significant 11-fold increase in Sildenafil plasma AUC (Area Under Curve)
The recommended dose should be taken one hour prior to sexual activity. The maximum frequency of dosing is once per day. The oral recommended dose is 50mg for most patients. Or as directed by the physician.
Based on effectiveness and toleration, the dose may be increased to a maximum recommended dose of 100mg or decreased to 25mg. NCI Sildenafil tabs may be taken with or without food.
Dosage Adjustment In Special Population
Geriatric use: Consider starting dose of 25 mg
Severe renal impairment: Consider starting dose of 25 mg
Hepatic impairment: Consider starting dose of 25mg.
For management of a suspected drug overdose, contact your regional Poison Control centre.
In studies with healthy volunteers of single doses of up to 800 mg, adverse events were similar to those seen at lower doses but incidence rates and severities were increased in cases of overdose standard-supportive be adopted as required. Renal dialysis is not expected to accelerate clearance as sildenafil is highly bound to plasma proteins and not eliminated in the urine.
Treatment of Priapism
Patients should be instructed to report any erections persisting for more than 4 hours to physician. The treatment of priapism/prolonged erection should be according to established medical practice. Physicians may refer to two suggested protocols for detumescence presented below .
1) Aspirate 40 to 60 ml blood from either left or right corpora using vacutainer and holder for drawing blood. Patient will often detumesce while aspirating. Apply ice for 20 minutes post aspiration if erection remains.
If procedure 1) is unsuccessful then try procedure 2).
2) Put patient in supine position. Dilute 10 mg phenylephrine into 20 ml distilled water for injection (0.05%) with an insulin syringe inject 0.1 to 0.2 ml (50-100 ug) into the corpora every 2 to 5 minutes, until the detumescence occurs. The occasional patient may experience transient bradycardia and hypertension when given phenylephrine injections, therefore monitor patient’s blood pressure and pulse every 10 minutes. Patients at risk include those with cardiac arrhythmias and diabetes. Refer to the prescribing information for phenylephrine before use.
Do not give phenylephrine to patients on MAO inhibitors. When phenylephrine is used within the first 12 hours of erection, the majority of patients will respond.
If procedure 2) is unsuccessful, then try procedure 3).
3) If the above measures fail to detumesce the patient, a urologist should be consulted as soon as possible, especially if the erection has been present for many hours. If priapism is not treated immediately, penile tissue damage and/or permanent loss of potency may result.
Store in a cool, dry and dark place.
KEEP ALL MEDICINE OUT IF REACH OF CHILDREN
Blister of 4 tablets.
Marketed in Nigeria by
NCI Pharm Chem Ind. Ltd.
Oshodi, Lagos, NIGERIA.
Manufactured in India by
Syncom Formulations (I) Ltd.
Pithampur (Dhar) 454-775, India