Sildenafil Oral Medication for Erectile Dysfunction - A Review

Abstract

A Common Drug That Is A Member Of The Phosphodiesterase-5 Inhibitor (Pde5-I) Class Is Sildenafil. It Is Mainly Prescribed To Treat Pulmonary Arterial Hypertension (Pah) And Erectile Dysfunction (Ed). This Study Offers A Thorough Analysis Of Sildenafil, Emphasising Its Pharmacological Underpinnings, Therapeutic Uses, And Modes Of Action. Furthermore, The Paper Addresses The Possible Negative Consequences And Contraindications Related To Its Application. To Effectively Manage Linked Disorders And Optimise Patient Care, Healthcare Providers Must Have A Complete Awareness Of These Aspects. In Order To Get The Best Possible Treatment Results With Sildenafil,The Study Emphasises The Significance Of Proper Patient Selection And Monitoring. By Raising The Amount Of Cyclic Guanosine Monophosphate In The Corpora Cavernosa, The Particular Phosphodiesterase Type V Inhibitor Sildenafil Improves Erection Upon Sexual Stimulation. This Has Completely Changed How Erectile Dysfunction Is Treated. Even While The Medication Seems Highly Promising And Has Few Side Effects, There Are Still A Lot Of Concerns About Its Safety, Effectiveness, And Potential For Abuse And Overuse.

Introduction

Introduction
Sildenafil, a phosphodiesterase-5 inhibitor (PDE5-I), is widely used to treat:

• Erectile Dysfunction (ED)

• Pulmonary Arterial Hypertension (PAH)

It works by enhancing nitric oxide effects, leading to smooth muscle relaxation and improved blood flow in the penis (for ED) and lungs (for PAH).

2. History & Development

• Originally developed by Pfizer as an anti-hypertensive.

• Redirected to ED treatment after participants reported improved erections during trials.

3. Mechanism of Action

• Sexual stimulation releases nitric oxide (NO) → increases cGMP → relaxes corpora cavernosa smooth muscles.

• Sildenafil inhibits PDE5, preserving cGMP levels.

• Note: It only works with sexual stimulation and doesn't increase libido.

4. Administration & Dosage

• For ED: 25, 50, or 100 mg orally, about 1 hour before sex; max once daily.

• For PAH:

  • Oral: 5 or 20 mg three times daily.

  • Injectable: 2.5 or 10 mg IV three times daily.

  • Not recommended for long-term pediatric use due to increased mortality risk.

• In Pregnancy: Use with caution due to limited data.

• Breastfeeding: Use cautiously—effects unknown.

5. Pharmacokinetics

• Absorption: Rapid, peaks at 30–120 mins; high-fat meals delay onset.

• Distribution: Widely distributed (Vd = 105 L); 96% protein-bound.

• Metabolism: Mainly via CYP3A4 and CYP2C9.

• Excretion: 80% via feces, 13% via urine.

6. Side Effects
Most common:

• Headache

• Flushing

• Indigestion

• Nasal congestion

• Photophobia

High doses may cause color vision disturbances due to PDE6 inhibition.

7. Clinical Trials & Efficacy

• Extensive trials show improved erections and satisfaction in men with ED, including those with diabetes and spinal cord injuries.

• Does not increase libido or spontaneous erections.

• Sustained efficacy over at least 6 months.

8. Research & Future Directions

• Instant-dissolving sildenafil wafers in development.

• Trials underway for female sexual dysfunction.

• Other ED drugs (e.g., apomorphine, phentolamine) under study but less promising.

Conclusion

For a long time, millions of men have been silently hoping for a straightforward treatment that would help them get or keep an erection. The first significant advancement in the treatment of erectile dysfunction was the introduction of intracavernous injection of vasoactive materials for erection in 1983. The ultimate objective, according to the American Urological Association Panel on the Treatment of Organic Erectile Dysfunction, is a treatment that is easy to use, dependable, and has few adverse effects. It seems that sildenafil satisfies these requirements. Compared to certain alternative treatment methods such injections into the corpus cavernosum, transurethral medication delivery, and penile prosthesis implantation, oral therapy allows for inconspicuous administration and is less invasive. Over time, additional information regarding the safety and effectiveness of sildenafil is probably going to surface because to its extensive use. These medications are probably going to help women have more fulfilling sex as well.

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Copyright © 2025 Mrs. Smriti Mathur. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.