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Sildenafil (Viagra) and ophthalmology
1Department of Ophthalmology, Stanford University School of Medicine, California 94305-5308, USA.
Survey of Ophthalmology
|December 14, 1999
Summary
Sildenafil citrate (Viagra) treats male impotence by inhibiting PDE5, but may cause temporary visual side effects like bluish haze due to mild PDE6 inhibition. Patients on nitrates should not use this medication.
Area of Science:
- Ophthalmology
- Pharmacology
- Urology
Background:
- Sildenafil citrate (Viagra) is an oral medication for erectile dysfunction.
- It functions by inhibiting phosphodiesterase-5 (PDE5) in the corpus cavernosum.
- This action facilitates penile erection in men with impotence.
Purpose of the Study:
- To review the ocular side effects and potential risks of sildenafil citrate.
- To inform ophthalmologists about the visual implications of this new drug.
- To provide guidance on patient counseling regarding sildenafil's use.
Main Methods:
- Review of existing clinical data and pharmacological information on sildenafil citrate.
- Analysis of reported cardiovascular and retinal vascular events.
- Assessment of the drug's mechanism of action on PDE5 and PDE6.
Main Results:
- Sildenafil inhibits PDE5 for erectile dysfunction treatment.
- A mild inhibitory effect on PDE6 can cause transient visual disturbances (e.g., bluish haze, light sensitivity).
- No long-term retinal damage has been reported, but long-term electroretinographic studies are lacking.
- Sildenafil can cause mild hypotension and is contraindicated with nitrates.
- Reported cardiovascular and retinal events are within expected rates for the elderly population.
Conclusions:
- Ophthalmologists must counsel patients on potential ocular side effects of sildenafil.
- Further clinical experience is needed to fully ascertain long-term risks.
- Contraindication with nitrates and awareness of visual side effects are crucial for patient safety.