Purpose: To report unilateral pupil-sparing third nerve palsy after use of sildenafil citrate (Viagra).
Method: Case report.
Results: A 56-year-old man with a history of tobacco abuse was treated for erectile dysfunction. Viagra, 50 mg, was taken once without adverse effect. Three weeks later, the patient took a second dose of Viagra (50 mg); 36 hours later he experienced a complete pupil-sparing third nerve palsy. Erythrocyte sedimentation rate, blood glucose level, magnetic resonance imaging, and magnetic resonance angiography were normal.
Conclusion: In a patient with microvascular disease, use of sildenafil may be associated with pupil-sparing third nerve palsy.