This development was credited largely “due to the introduction of generic products. Sildenafil Viagra. The amount of medicine that you take depends on the strength of the medicine. Viagra is available in 3 doses of 25, 50, and mg doses or as single packet doses 5. Its effects might last longer if you have mild to moderate ED. Click here for an email preview.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 . Manufacture and sale of sildenafil citrate drugs known as “generic Viagra” is common in India, where Pfizer’s patent claim does not apply. Trade names include Kamagra (Ajanta . Viagra is available in 3 doses of 25, 50, and mg doses or as single packet doses (5). Whereas, Kamagra comes in doses of 50 or mg for the tablet variant. Kamagra also has an oral jelly variant, which only comes in mg sachets. Typically, your first prescription would be for 50mg tablets and is changed See more.