I have been using viagra of late, just using half a tablet took one 10.30 sun morning several hours later was having sex, everything fine, had an orgasm during penetrative sex, no problem felt normal. around 3pm which is over 4 hours since i took the viagra, i was having hand relief at moment of ejeculation the most awful blinding headache, all round the top of my head, deep searing blinding headache which lasted 5 mins and dulled a bit but took an hour to go. i had taken a half of viagra the previous thursday so this is 2 halves in 4 days. masturbated today to see if the pain would come back and it did, not as bad as before but same pain and pretty bad. the only time i have felt pain like this is when i have been pissed and masturbate the following morning. anyone suffer the same effects, is this normal for viagra. i have taken viagra before and generally have penetrative sex, things were different with the hand relief.