sildenafil-citrate and Optic-Nerve-Diseases

Topics: Humans; Optic Nerve Diseases; Optic Neuritis; Optic Neuropathy, Ischemic; Sildenafil Citrate

Since the launch in 1998 of the anti-impotence drug sildenafil (viagra), the American food and drug administration has identified 50 cases of drug-related blindness, the so-called nonarteritic anterior ischemic optic neuropathy. This, very serious, side effect frequently leads to sudden, mostly irreversible loss of vision, and there is no proven effective treatment to cure patients or to prevent recurrence. The mechanism of ischemic optic neuropathy is not clear, but it could be related to the fact that the ophthalmic and central retinal arteries have an autoregulation of their own blood flow without any autonomic nerve supply; vasoreactivity could be lower albeit efficient, and therefore more vulnerable to systemic modifications of the circulation. But decreased visual acuity and loss of visual ability also are, although uncommon, anesthesiological and surgical complications. These data are consistent with the hypothesis that sildenafil, surgery and anesthesia, taken together, could be a potentially dangerous cocktail of risk factors for sudden irreversible loss of vision. To reduce the risk, sildenafil use should be avoided at least one week before surgical operations, since the reported cases of blindness developed 36h after drug ingestion.

Topics: Anesthesia; Blindness; Carbon Dioxide; Humans; Hypertension; Ischemia; Male; Optic Nerve; Optic Nerve Diseases; Optic Neuropathy, Ischemic; Piperazines; Postoperative Complications; Purines; Risk; Risk Factors; Sildenafil Citrate; Sulfones; Vasodilator Agents

To highlight the challenges of postmarketing surveillance for drug-related adverse events in the practice of ophthalmology.. A retrospective review of the medical literature and postmarketing surveillance databases.. MEDLINE literature review of sildenafil-associated or amiodarone-associated optic neuropathy and chloramphenicol-associated blood dyscrasias.. Sildenafil, amiodarone, and chloramphenicol may all cause adverse ocular events; however, the data are not conclusive.. Reports in peer-reviewed medical journals may be proven incorrect over time. For drug-induced adverse ocular events, there is little true science after the drug reaches the marketplace, so the percentage of incorrect conclusions may be high. Clinicians should be wary of reports of adverse ocular effects until data are confirmed by multiple authors over the long-term. Even so, spontaneous reports from postmarketing surveillance databases may be the first and only signal of an adverse ocular event.

Topics: Adverse Drug Reaction Reporting Systems; Amiodarone; Chloramphenicol; Databases, Factual; Drug-Related Side Effects and Adverse Reactions; Humans; Optic Nerve Diseases; Paraproteinemias; Piperazines; Product Surveillance, Postmarketing; Purines; Retrospective Studies; Sildenafil Citrate; Sulfones