Hi,thanks for query.There are no medicines or vaccines for preventing HIV at present.You can only avoid infection by avoiding unprotected sex.This is the most common mode of spreading infection.
wishing you good health.

Hello;
welcome to HealthcareMagic
HIV is a virus which can stay in body for years without presenting any symptoms and when it destroys the immune system the symptoms start appearing.There are few drugs which help to stop the further growth and they are antivirals but they can be prescribed only by specialist and you will not get them without prescription.The best medicine will be the one which your body will tolerate and respond to.So please consult a Physician at a private or even at a government hospital ;get examined and investigated and depending upon your condition they will prescribe the required medicines.
Thanks