The main findings were that for reduced fungus,
terbinafine was found to be significantly better than itraconazole and griseofulvin, and
terbinafine was better tolerated than itraconazole.
ref:http://en.wikipedia.org/wiki/Onychomycosis
What you have read is correct. You could discuss this finding with your doctor and get him to prescribe it for you. Since the treatment is long-term it is better to go with onr which is tolerated better by the body.