erectile dysfunction
"Used Viagra as an alternate after Cialis.  Cialis at first provided repeated strong erections in a 24 hour period after years of severe ED.  However after 3 to 4 uses the erections were too weak and too short lived to sustain intercourse, so I switched to Viagra.  At first results were good.  I had fewer erections but they were longer lasting than Cialis and quite firm.  However this only last 2 or 3 uses before the same symptoms appear as the Cialis, erections to weak and short lived for intercourse.  Also moderate to severe headache, stuffiness and fullness like a severe head cold."