You’ll soon start receiving the latest Mayo Clinic health information you requested in your inbox. Medicines that you take by mouth are called oral medicines. This product is available in the following dosage forms: Tablet Suspension There is a problem with information submitted for this request. Whereas, Kamagra comes in doses of 50 or mg for the tablet variant. Viagra: Do They Work the Same?Sildenafil (Viagra). This medicine works best when you take it on an empty stomach an hour before sex. The body takes longer to absorb it after a high-fat meal or .  · Cialis vs Viagra – What’s the difference between them? Do you know these 11 amazing facts about Viagra? Is generic Viagra available in the U.S.? View more FAQ.  · Viagra; Descriptions. Sildenafil is used to treat men who have erectile dysfunction (also called sexual impotence). Sildenafil belongs to a group of medicines .