Product Overview
[Drug name]
Generic name: Sildenafil citrate tablets
Trade name: Aijiu Sildenafil citrate tablets 25mg*7 tablets*2 plates
Pinyin full code: AiJiu GouYuanSuanXiDiNaFeiPian 25mg*7Pian*2Ban
[Main ingredients]
The main ingredients of this product are: Sildenafil citrate, its chemical name is: 1-{4-ethoxy-3-(6,7-dihydro-1-methyl-7-oxo-3-propyl-1hydrogen-pyrazolo[4,3d]pyrimidin-5-yl)benzenesulfonyl}-4-methylpiperazine citrate Molecular formula: C22H30N6O4S·C6H8O7 Molecular weight: 666.70
[Properties]
This product is a white or off-white film-coated tablet, which is white or off-white after removing the coating.
[Indications/Main Functions]
Sildenafil is suitable for the treatment of erectile dysfunction.
[Specifications]
25mg*7 tablets*2 plates
[Dosage and Administration]
For most patients, the recommended dose is 50 mg, taken as needed about 1 hour before sexual activity; but it can be taken at any time within 0.5-4 hours before sexual activity. Based on efficacy and tolerability, the dose can be increased to 100 mg (maximum recommended dose) or reduced to 25 mg. Take up to 1 time a day. In the absence of sexual stimulation, the recommended dose of sildenafil is ineffective. The following factors are associated with increased plasma sildenafil levels (AUC): age over 65 years (increase of 40%), liver damage (such as cirrhosis, increase of 80%), severe renal impairment (creatinine clearance <30 ml/min, increase of 100%), and concurrent use of potent cytochrome P4503A4 inhibitors (ketoconazole, itraconazole (increase of 200%), erythromycin (increase of 182%), saquinavir (increase of 210%)]. Since higher plasma levels may increase both efficacy and the incidence of adverse events, the starting dose for these patients is 25 mg. A study conducted in healthy subjects without HIV infection showed that Ri Tonavir can significantly increase the blood level of sildenafil (AUC increased by 11 times, see "Drug Interactions"). In view of this, it is recommended that patients taking ritonavir at the same time should not take more than 25 mg of medication within 48 hours. Sildenafil can enhance the antihypertensive effect of nitrates, so patients taking any dosage form of nitric oxide donors and nitrates are prohibited from taking sildenafil. When sildenafil needs to be used in combination with alpha-receptor blockers, the patient has been treated with alpha-receptor blockers to achieve a stable state before sildenafil treatment, and sildenafil should be taken from the lowest dose (see [Drug Interactions]).
[Adverse Reactions]
See the instructions for details.
[Contraindications]
Nitrates: Due to the known effects of sildenafil citrate tablets on the nitric oxide/cGMP pathway (see [Pharmacology and Toxicology]), sildenafil can enhance the hypotensive effect of nitrates. Therefore, patients taking nitric oxide donors (such as any form of organic nitrates or organic nitrites), whether taking them regularly or intermittently, are contraindicated. PDE5 inhibitors (including sildenafil) are prohibited from being used in combination with guanylate cyclase agonists (such as riociguat) because this may cause symptomatic hypotension. It is not clear when patients can safely take nitrates (if necessary) after taking sildenafil. Based on pharmacokinetic data in healthy volunteers, a single oral dose of 100 mg results in a plasma sildenafil concentration of approximately 2 ng/ml (peak plasma concentration of approximately 440 ng/ml) 24 hours later (see [Pharmacokinetics]). The following patients had plasma sildenafil concentrations 3 to 8 times higher than healthy volunteers 24 hours after taking the drug: patients over 65 years old, with liver damage (such as cirrhosis), severe renal damage (creatinine clearance below 30ml/min), and those taking strong inhibitors of cytochrome P4503A4 such as erythromycin. Although the blood concentration of sildenafil 24 hours after taking the drug is much lower than the peak concentration, it is not known whether it is safe to take nitrates at this time. Patients who are known to be allergic to any of the ingredients in this product are contraindicated. Warning Cardiovascular: Sexual activity is potentially dangerous to the heart in patients with existing cardiovascular disease.Therefore, patients whose cardiovascular status is not suitable for sexual activity should generally not use drugs for erectile dysfunction, including sildenafil. Sildenafil causes systemic vasodilation, resulting in a transient decrease in blood pressure in the supine position in healthy volunteers (mean maximum decrease of 8.4/5.5 mmHg) (see [Pharmacology and Toxicology]). In most patients, this effect is usually negligible, but physicians should carefully consider whether this vasodilation effect will cause adverse consequences in patients with cardiovascular disease before prescribing, especially during sexual activity. Patients with the following underlying diseases may be particularly sensitive to the effects of vasodilators, including sildenafil - including left ventricular outflow tract obstruction (such as aortic stenosis, idiopathic hypertrophic subaortic stenosis) and diseases with severe impairment of autonomic control of blood pressure. Such patients should use the drug with caution. Currently, there are no controlled clinical trial data on the safety and efficacy of sildenafil in the following populations. Prescriptions should be used with caution for these patients: patients who have had myocardial infarction, shock, or life-threatening arrhythmias within the last 6 months; patients with resting hypotension (blood pressure below 90/50 mmHg) or hypertension (blood pressure above 170/110 mmHg); patients with heart failure or unstable angina due to coronary heart disease; patients with pigmentary retinitis (a few patients with this disease have hereditary abnormalities of retinal phosphodiesterase). Patients with sickle cell anemia or related anemia. Prolonged erection and abnormal penile erection: After the approval of sildenafil citrate tablets abroad, there have been a few reports of prolonged erection (more than 4 hours) and abnormal erection (painful erection for more than 6 hours).If an erection persists for more than 4 hours, the patient should seek medical attention immediately. If priapism is not treated immediately, penile tissue may be damaged and permanent erectile dysfunction may occur. Sildenafil should be used with caution in patients with the following diseases: penile anatomical malformations (such as penile deviation, cavernous fibrosis, Peyronie's disease), diseases that predispose to priapism (such as sickle cell anemia, multiple myeloma, leukemia). However, there are no controlled clinical data on the safety or efficacy of this product in patients with sickle cell anemia or related anemias. Adverse reactions caused by co-administration with ritonavir: Concomitant administration of the protease inhibitor ritonavir significantly increases the blood concentration of sildenafil (AUC increases 11 times). Sildenafil should be used with caution in patients taking ritonavir. There is limited information on the effects of high blood concentrations of sildenafil on subjects, except that visual abnormalities are more common at high doses. Some healthy subjects taking high doses of sildenafil (200-800 mg) reported decreased blood pressure, syncope, and prolonged erection. To reduce the likelihood of adverse events in patients taking ritonavir, it is recommended that their sildenafil dosage be reduced.
[Precautions]
General matters When diagnosing erectile dysfunction, the underlying cause should be identified, and appropriate treatment plans should be determined after a comprehensive medical examination. Before using sildenafil on patients, it is important to note the following important issues: Hypotension when used in combination with alpha-blockers or antihypertensive drugs Alpha-blockers: PDE5 (phosphodiesterase type 5) inhibitors should be used with caution when used in combination with alpha-blockers. PDE5 inhibitors (including this product) and alpha-blockers are both vasodilators and have the effect of lowering blood pressure. When vasodilators are used in combination, it can be expected that the effects on blood pressure may be additive. In some patients, the combination of these two types of drugs can significantly lower blood pressure and cause symptoms of hypotension (such as dizziness, lightheadedness, and syncope) (see [Drug Interactions]). The following situations should also be noted: Before a patient receives sildenafil treatment, he should have reached a stable state of alpha-blocker treatment. Patients who take alpha-blockers alone to treat hemodynamic instability are at increased risk of hypotension symptoms after taking PDE5 inhibitors in combination. - For patients who have reached a stable state on α-blocker therapy, PDE5 inhibitors should be started at the lowest dose. - For patients who have already taken the ideal dose of PDE5 inhibitors, α-blocker therapy should be started at the lowest dose. The simultaneous use of PDE5 inhibitors may further reduce blood pressure as the α-blocker dose is gradually increased.- The safety of combined use of PDE5 inhibitors and alpha-blockers may be affected by other factors, including insufficient intravascular volume and other antihypertensive drugs. Antihypertensive drugs: Sildenafil dilates systemic blood vessels and may enhance the antihypertensive effect of other antihypertensive drugs. Patients taking multiple antihypertensive drugs were included in the main clinical trials. Another independent drug interaction study showed that when hypertensive patients taking 5mg or 10mg of amlodipine were given 100mg of sildenafil citrate tablets, systolic and diastolic blood pressures were further reduced by an average of 8mmHg and 7mmHg respectively (see [Drug Interactions]). In three drug interaction studies, patients with benign prostatic hyperplasia (BPH) who were stable on doxazosin were treated with the alpha-blocker doxazosin (4 mg and 8 mg) and sildenafil (25 mg, 50 mg, or 100 mg). In these study populations, a further decrease in supine blood pressure was observed by an average of 7/7 mmHg, 9/5 mmHg, and 8/4 mmHg, respectively, while a further decrease in standing blood pressure was observed by an average of 6/6 mmHg, 11/4 mmHg, and 4/5 mmHg, respectively. When a higher dose of sildenafil was taken with doxazosin (4 mg), individual patients reported symptoms of postural hypotension within 1 to 4 hours of taking the drug, including dizziness and lightheadedness, but not syncope. Patients treated with alpha-blockers may experience symptoms of hypotension in some patients when taking sildenafil at the same time. Therefore, sildenafil doses exceeding 25 mg should not be taken within 4 hours of taking an alpha-blocker. Safety database analysis showed that there was no difference in side effects among patients taking sildenafil with or without antihypertensive drugs.In post-marketing experience, there have been reports of prolonged erections and priapism associated with sildenafil. If an erection persists for more than 4 hours, the patient should seek medical attention immediately. If priapism is not treated immediately, penile tissue may be damaged and permanent erectile dysfunction may occur. Concomitant use with other PDE5 inhibitors or other erectile dysfunction treatments: The safety and efficacy of other PDE5 inhibitors, other pulmonary arterial hypertension (PAH) treatments containing sildenafil (Revatio), or other erectile dysfunction treatments have not been studied in combination with this product. Such combination therapy may further lower blood pressure. Therefore, combined use is not recommended. Effects on bleeding: Post-marketing bleeding events have been reported in patients who have taken sildenafil citrate tablets. A causal relationship between this product and these events has not been established. Sildenafil citrate tablets have no effect on human bleeding time, whether used alone or in combination with aspirin. However, in vitro, sildenafil citrate enhances the antiaggregation effect of sodium nitroprusside (a nitric oxide donor) on human platelets. In addition, in anesthetized rabbits, the combination of heparin and sildenafil has an additive effect on the prolongation of bleeding time, but similar human studies have not been conducted. The safety of sildenafil citrate in patients with bleeding disorders and active peptic ulcers is currently unknown. Patient Information Physicians should explain to patients that sildenafil is contraindicated when taken with nitrates (regularly or intermittently). Physicians should inform patients that sildenafil has the potential to enhance the hypotensive effect of alpha-blockers and other antihypertensive drugs.Taking sildenafil with alpha-blockers may cause hypotension in some patients. When sildenafil and alpha-blockers are used together, patients should have reached a stable state of alpha-blocker treatment before sildenafil treatment, and sildenafil should be started at the lowest dose.Physicians should explain to patients that sexual activity is potentially dangerous to the heart when cardiovascular risk factors are present. If symptoms such as angina, dizziness, and nausea occur at the beginning of sexual activity, sexual activity should be stopped and discussed with the doctor. Effects on the eyes: Physicians should inform patients that if sudden vision loss occurs in one or both eyes, they should immediately stop taking all phosphodiesterase type 5 (PDE5) inhibitors, including sildenafil citrate tablets, and consult a doctor. This condition may be a manifestation of non-arteritic anterior ischemic optic neuropathy (NAION), a disease that can cause vision loss, including permanent loss. Rare reports of NAION related to medication time have been reported in all post-marketing applications of PDE5 inhibitors. An observational case-crossover study evaluated the risk of NAION when using PDE5 inhibitors just before (within 5 half-lives) NAION occurred, compared with previous use of PDE5 inhibitors. The results showed that the risk of NAION increased by approximately 2 times, with a risk estimate of 2.15 (95% CI 1.06, 4.34). A similar study reported consistent results, with a risk estimate of 2.27 (95% CI 0.99, 5.20). Other risk factors for NAION (such as optic disc "crowding") may be involved in the NAION that occurred in these studies. Rare postmarketing reports and associations between PDE5 inhibitor use and NAION in observational studies have not demonstrated a causal relationship between PDE5 inhibitor use and NAION (see [Adverse Reactions]/Postmarketing Experience).Published literature data show that in the general population, the annual incidence of NAION is 2.5 to 11.8 cases per 100,000 males (≥50 years old). If sudden vision loss occurs, patients should be advised to stop taking sildenafil and consult a physician immediately. For patients with potential risk factors for NAION, physicians should consider whether they will be adversely affected by the use of PDE5 inhibitors. Individuals who have already experienced NAION are at increased risk of NAION recurrence. Physicians should inform patients who have experienced unilateral NAION that they are at increased risk of NAION recurrence regardless of whether vasodilator drugs such as PDE5 inhibitors have adverse effects on them. In these patients, PDE5 inhibitors (including sildenafil) should be used with caution only when the expected benefits outweigh the risks. The risk of NAION in patients with "crowded" optic discs is also believed to be higher than that of the general population, but there is insufficient evidence to support the screening of potential users of PDE5 inhibitors (including this product) based on this rare disease. There are no controlled clinical data on the safety or efficacy of this product for patients with retinitis pigmentosa (a small number of whom have a genetic disease of retinal phosphodiesterase). It is not certain whether these events are directly related to the use of PDE5 inhibitors or are related to other factors. Physicians should inform patients who have experienced unilateral NAION that their risk of recurring NAION is increased regardless of whether vasodilators such as PDE5 inhibitors have adverse effects on them (see "Adverse Reactions/Post-Marketing Experience/Special Sensations" section). Hearing loss: Physicians should inform patients that if hearing loss or loss occurs suddenly, they should stop taking PDE5 inhibitors (including this product) and seek medical attention as soon as possible.Such events may be accompanied by tinnitus and dizziness, and are reported to be temporally related to the use of PDE5 inhibitors (including sildenafil citrate tablets). However, it is not certain whether such events are directly related to the use of PDE5 inhibitors or other factors (see [Adverse Reactions]/Pre-marketing Experience and Post-marketing Experience). Doctors should warn patients: After the approval of sildenafil citrate tablets abroad, there have been a small number of reports of prolonged erections (more than 4 hours) and abnormal erections (painful erections for more than 6 hours). If the erection lasts for more than 4 hours, the patient should seek medical attention immediately. If abnormal erections are not treated immediately, penile tissue may be damaged and may cause permanent loss of erectile function. Doctors should inform patients that this product should not be used in combination with other PDE5 inhibitors. The safety and effectiveness of this product in combination with other PDE5 inhibitors have not been studied. Patient counseling advice on sexually transmitted diseases: Sildenafil does not protect against sexually transmitted diseases. Patients should be informed of measures to prevent sexually transmitted diseases (including human immunodeficiency virus, HIV) as appropriate. Effects on the ability to drive and use machines Because dizziness and visual changes have been reported in clinical studies with sildenafil, patients should be informed of their possible reactions to sildenafil before driving or operating machinery. The effects of sildenafil on the ability to drive and use machines have not been studied.
