Men who have weak impotence or erectile dysfunction may not experience strong or prolonged erections during intercourse. Kamagra Effervescent cures male sexual problems. This medicine contains an ingredient called sildenafil which helps in increasing the blood flow to the tissues of the penis in men. You can take this medicine before or after food. The effect of this medicine lasts for 4 to 6 hours. Take this medicine as per the doctor’s advice. Do not consume fatty foods or alcoholic beverages with this medicine.