Since a straddle injury or use of a narrow saddle can obstruct and impair arteries to the penis, bicycle riding is also considered a risk factor for erectile dysfunction. This is a classic example of why people with ED need complete care: a psychological exam, history and physical exam, and diagnostic studies with long term follow-up care. This means that vardenafil Levitra should act longer than sildenafil Viagra but the clinical significance is not known. It will not spontaneously cause an erection. For VSS, subjects were given a free choice from a selection of sexually explicit magazines and videos and were to view similar materials on each occasion.The most common side effects are facial flushing (1 in 10), headaches (1 in 6), stomach pain, nasal congestion, nausea, dizziness, rash, urinary tract infections (UTIs), diarrhea, and an inability to differentiate between the colors green and blue. Do not combine Viagra with other PDE5 inhibitors (for example, vardenafil [Levitra], tadalafil. Vision changes. Muscle pain. But there are some differences. With Viagra, there is a higher risk of vision changes than with Cialis. Among people who take Viagra or sildenafil, 3% get blue vision that lasts a few hours. On the other hand, Cialis has a slightly higher risk of muscle pain than Viagra and vardenafil.  · How much Teva sildenafil is too much? The maximum daily dosage is mg, and that amount should not be exceeded because it can lead to severe side effects like: vision and hearing problems.