The phosphodiesterase – 5 enzyme (PDE-5) is found all over the human body and especially within the penis, pulmonary blood vessels, smooth muscles, and platelets. It is involved in various physiological processes such as smooth muscle contraction and relaxation. PDE-5 has the largest distribution in the penile corpus cavernosum and because sildenafil is a competitive PDE-5 antagonist, it is able to work selectively on this part of the body to relax muscles and increase blood flow thereby producing an erection in men.1 Sildenafil also acts on PDE-5 in the pulmonary vasculature causing the blood vessels to relax and widen to decrease mean pulmonary artery pressure.
In the management of erectile dysfunction, sildenafil is commonly administered orally and sublingually. After oral ingestion, sildenafil citrate is rapidly absorbed within the small intestine, however much of it is metabolized quickly by the liver. Sildenafil taken orally may take between 30 and 120 minutes after ingestion in fasting individuals to work.1, 2, 3
Sildenafil is the first-line therapy option in the management of erectile dysfunction in men. It is also used in the management of pulmonary hypertension, persistent pulmonary hypertension in newborns, Raynaud’s phenomenon resistant to other vasodilators, as well as in the prevention of pulmonary edema at high altitudes.4, 5, 6
Commercially-Available Sildenafil Options
Sildenafil was FDA approved for use in treating erectile dysfunction in 1998. Today, it is available commercially as an oral tablet in various strengths (20 mg, 25 mg, 50 mg, and 100 mg), a 10 mg/mL oral suspension, and a 0.8 mg/mL intravenous injection.
Compounded Sildenafil Options
Since sildenafil is already commercially available as an oral tablet, compounded sildenafil oral disintegrating tablets (ODT) are reserved for patients that require a higher or more customizable dosage than what is available commercially and for those that would benefit from an oral disintegrating formulation as determined by a prescriber. The most popular formulation compounded at Galleria Medical Pharmacy is sildenafil 125 mg ODT. An oral disintegrating tablet is similar to a hard tablet taken orally but is designed to quickly disintegrate in the mouth. It may also be placed under the tongue for a potential faster onset of action and to reduce upset stomach sometimes experienced with oral tablets. ODTs are quad-scored and can be broken into smaller dosage forms if necessary.
Store this medication at 68°F to 77°F (20°C to 25°C) and away from heat, moisture and light. Keep all medicine out of the reach of children. Throw away any unused medicine after the beyond use date. Do not flush unused medications or pour down a sink or drain.
- McCullough, A.R., “Four-Year Review of Sildenafil Citrate”, Reviews in Urology, vol.4 supp 3, S26 – S38. 2002. Available: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1476025/
- “Sildenafil”, Drug Bank. Available: https://go.drugbank.com/drugs/DB00203
- Cheitlin, M.D., Hutter, A. M., Brindis, R.G., Ganz,P., Kaul,S., Russell, R.O., Zusman, R. M., Forrester, J.S., Douglas, P.S., Faxon, D.P., Fisher, J.D., Gibbons, R.J., Halperin, J.L., Hochman, J.S., Kaul, S., Weintraub, W.S., Winters, W.L., Wolk, M.J.,” Use of Sildenafil (Viagra) in Patients With Cardiovascular Disease”, Circulation, vol.99 issue 1. 1999. Available: https://www.ahajournals.org/doi/10.1161/01.CIR.99.1.168
- “Sildenafil citrate”, Prescibers’ Digital Reference. Available: https://www.pdr.net/drug-summary/Viagra-sildenafil-citrate-471
- Levien, T.L., “Advances in the treatment of Raynaud’s phenomenon”, Vascular Health and Risk Management, vol. 6, pp. 166-167. 2010. Available: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2860448/
- “Sildenafil Effectively Treats Raynaud’s Phenomenon”, Emergency Medicine News: vol.28 Issue 3, pp. 29. 2006. Available: https://journals.lww.com/em-news/fulltext/2006/03000/sildenafil_effectively_treats_raynaud_s_phenomenon.35.aspx
Compounding Pharmacy Statement
Sildenafil ODTs are compounded with drug components whose suppliers are registered with the FDA. While Galleria Medical Pharmacy adheres to USP <795> guidelines and applicable state and federal regulations to meet the required quality standards, the statements made regarding compounded sildenafil ODTs have not been evaluated by the FDA for safety or clinical effectiveness. As such, this preparation is not intended to diagnose, treat, cure, or prevent any disease. For inquiries concerning this preparation, please contact (504) 267-9876.