Suggest Remedy For Fungal Patches

Hi, my boyfriend has been struggling with tinea versicolor pretty much all over the top half of his body. They are clustered reddish/brown patches that he gets every spring/summer. He went to the doctors a few years ago and they told him it was a fungus and provided him with antibiotics. Since we already know what the skin condition is, is there another remedy or medication we can buy without a prescription to get the fungus patches to go away? And also what can he use to keep them from coming back? Thank so much!