Purpose Sildenafil can cause transient, mild ERG changes in healthy individuals taking large single doses. Although the drug was originally intended for intermittent use in erectile dysfunction, it has now been approved for chronic use in subjects with pulmonary arterial hypertension (PAH). The purpose of our study is to investigate possible ERG changes in subjects using large doses of sildenafil on a chronic daily basis. Methods We examined five subjects with PAH taking sildenafil daily for 1–4 years. Full-field electroretinogram (ERG), multifocal ERG (mfERG), and color testing were performed. Three of the subjects returned on a later date for challenge off and on the medication. Results On chronic daily sildenafil, color vision testing was normal, and ERG and mfERG amplitudes were normal; however, cone implicit times on drug were modestly lengthened. There were no consistent full-field ERG changes when off the drug, but the mfERG showed a small amplitude increase and implicit time decrease, which returned 1 h after re-dosing. Conclusion There was a modest lengthening of cone implicit time on chronic daily doses of sildenafil and a hint that some of these changes may be reversible in the short term. It does not appear that chronic sildenafil usage at these dosage levels is seriously toxic or threatening to vision.
This is a preview of subscription content, log in to check access.
We thank Lorella Cabael for assistance with the experiments and data preparation.
MFM has been a consultant to Eli Lilly Co. and Pfizer Inc. RTZ is a recipient of an Actelion-Entelligence career development grant and a consultant to Actelion, United Therapeutics, and Gilead Pharmaceuticals.
Goldstein I, Lue TF, Padma-Nathan H et al (1998) Oral sildenafil in the treatment of erectile dysfunction. Sildenafil Study Group. N Engl J Med 338:1397–1404PubMedCrossRefGoogle Scholar
Pomeranz HD, Smith KH, Hart WM Jr et al (2002) Sildenafil-associated nonarteritic anterior ischemic optic neuropathy. Ophthalmology 109:584–587PubMedCrossRefGoogle Scholar
Jägle H, Jägle C, Serey L, Sharpe LT (2005) Dose-dependency and time-course of electrophysiologic short-term effects of VIAGRA: a case study. Doc Ophthalmol 110:247–254PubMedCrossRefGoogle Scholar
Jagle H, Jagle C, Serey L et al (2004) Visual short-term effects of Viagra: double-blind study in healthy young subjects. Am J Ophthalmol 137:842–849PubMedCrossRefGoogle Scholar
Luu JK, Chappelow AV, McCulley TJ et al (2001) Acute effects of sildenafil on the electroretinogram and multifocal electroretinogram. Am J Ophthalmol 132:388–394PubMedCrossRefGoogle Scholar
Galie N, Ghofrani HA, Torbicki A et al (2005) Sildenafil citrate therapy for pulmonary arterial hypertension. N Engl J Med 353:2148–2157PubMedCrossRefGoogle Scholar
Fries R, Shariat K, von Wilmowsky H et al (2005) Sildenafil in the treatment of Raynaud’s phenomenon resistant to vasodilatory therapy. Circulation 112:2980–2985PubMedGoogle Scholar
Sairam K, Kulinskaya E, McNicholas TA et al (2002) Sildenafil influences lower urinary tract symptoms. BJU Int 90:836–839PubMedCrossRefGoogle Scholar
Marmor MF, Holder GE, Seeliger MW et al (2004) Standard for clinical electroretinography (2004 update). Doc Ophthalmol 108:107–114PubMedCrossRefGoogle Scholar
Hood DC, Bach M, Brigell M et al (2008) ISCEV guidelines for clinical multifocal electroretinography (2007 edition). Doc Ophthalmol 116:1–11PubMedCrossRefGoogle Scholar
D’Alonzo GE, Barst RJ, Ayres SM et al (1991) Survival in patients with primary pulmonary hypertension. Results from a national prospective registry. Ann Intern Med 115:343–349PubMedGoogle Scholar
O’Callaghan D, Gaine SP (2007) Combination therapy and new types of agents for pulmonary arterial hypertension. Clin Chest Med 28:169–185, ixGoogle Scholar
Estrade M, Grondin P, Cluzel J et al (1998) Effect of a cGMP-specific phosphodiesterase inhibitor on retinal function. Eur J Pharmacol 352:157–163PubMedCrossRefGoogle Scholar
Danciger M, Blaney J, Gao YQ et al (1995) Mutations in the PDE6B gene in autosomal recessive retinitis pigmentosa. Genomics 30:1–7PubMedCrossRefGoogle Scholar
Farber DB, Lolley RN (1974) Cyclic guanosine monophosphate: elevation in degenerating photoreceptor cells of the C3H mouse retina. Science 186:449–451PubMedCrossRefGoogle Scholar
McCullough AR, Steidle CP, Klee B, Tseng L-J (2008) Randomized, double-blind, crossover trial of sildenafil in man with mild to moderate erectile dysfunction: Efficacy at 8 and 12 hours postdose. Urology 71:686–692PubMedCrossRefGoogle Scholar