Is it really safe to use oral Lamisil?

I had my big toenail removed today because of a really bad fungus and the doctor said he recommends me taking oral Lamisil for 12 weeks. The thing is that I heard it can eff up your liver. But I already had a blood test done at the hospital (he needs to make sure my liver doesn't act up after I take the Lamisil, so he can compare blood tests with my first one). I have also heard that it doesn't even work because the fungus is so hard to treat. Should I just not take it or try something else first once the nail grows back (God knows when that'll be)? I don't really want to take this medication.