Fildena is a medication commonly used to treat erectile dysfunction (ED) in men. It is manufactured by Fortune Healthcare and is often compared to Viagra, as both drugs share the same active ingredient. Here’s a detailed look at the active ingredients and the pharmacology of Fildena:
Active Ingredient
Sildenafil Citrate: The primary active ingredient in Fildena 100 is sildenafil citrate. Sildenafil is a phosphodiesterase type 5 (PDE5) inhibitor, which means it works by blocking the enzyme PDE5.
Mechanism of Action
Inhibition of PDE5: Sildenafil citrate inhibits the PDE5 enzyme, which is primarily found in the corpus cavernosum of the penis. PDE5 is responsible for breaking down cyclic guanosine monophosphate (cGMP), a molecule that helps relax smooth muscles.
Increased cGMP Levels: By inhibiting PDE5, sildenafil citrate increases the levels of cGMP. Elevated cGMP levels lead to smooth muscle relaxation in the corpus cavernosum.
Enhanced Blood Flow: The relaxation of smooth muscles allows blood to flow more freely into the penile arteries, leading to improved blood engorgement and an erection when combined with sexual stimulation.
Pharmacokinetics
Absorption: Sildenafil is absorbed rapidly after oral administration. The onset of action typically occurs within 30 to 60 minutes, with peak plasma concentrations reached within this time frame.
Distribution: Sildenafil has a volume of distribution of approximately 105 L, indicating extensive distribution into tissues. It is about 96% bound to plasma proteins.
Metabolism: Sildenafil is metabolized primarily in the liver by the enzymes CYP3A4 and CYP2C9. The main circulating metabolite, N-desmethyl sildenafil, has similar properties but is less potent.
Elimination: The drug has a half-life of about 3 to 5 hours. It is excreted predominantly as metabolites in the feces (approximately 80% of the administered dose) and to a lesser extent in the urine (approximately 13%).
Indications
Fildena is indicated for the treatment of erectile dysfunction. It helps men achieve and maintain an erection sufficient for sexual intercourse.
Dosage and Administration
Fildena is available in various strengths, including 25 mg, 50 mg, and 100 mg. The typical starting dose is 50 mg taken as needed, about one hour before sexual activity. Depending on efficacy and tolerability, the dose may be increased to 100 mg or decreased to 25 mg.
Side Effects
Common side effects of Fildena include:
Headache
Flushing
Dyspepsia (indigestion)
Nasal congestion
Dizziness
Visual disturbances (blurred vision, changes in color vision)
Precautions and Contraindications
Cardiovascular Risk: Sildenafil can cause a mild and transient decrease in blood pressure. It should be used with caution in patients with cardiovascular disease.
Nitrate Interaction: Sildenafil should not be used in conjunction with nitrates or nitric oxide donors, as the combination can lead to a severe drop in blood pressure.
Other Conditions: Use with caution in patients with a history of priapism, anatomical deformation of the penis, or conditions that predispose them to priapism (e.g., sickle cell anemia, multiple myeloma, leukemia).
Conclusion
Fildena, with sildenafil citrate as its active ingredient, is an effective treatment for erectile dysfunction. Its pharmacological action involves the inhibition of the PDE5 enzyme, leading to increased levels of cGMP, smooth muscle relaxation, and enhanced blood flow to the penis. While generally safe, it should be used under medical supervision, especially in individuals with underlying health conditions or those taking other medications.
