Sildenafil citrate is found as the active ingredient in kamagra effervescent tablet. This drug is used to treat erectile dysfunction in men. The effect of this drug lasts for 4 to 6 hours. And if the effect of this medicine lasts for more than 6 hours, seek the help of a doctor immediately. Seek medical advice before using this medication. So you can see the good effect of this medicine. Take medicine only if you have ED problem.