I Am Current Taking Terinafine Once A Day For A

I am current taking terinafine once a day for a fungal infection I have on my toes .I developed an infection on my thumb that I think started as an infected cuticle. The doctor prescribed an atibiotic ,sulfmeth/trimethoprim 800/1600 tb.I am to take it twice a day for 10days. My questions are :Are there contraindications for using this drug combo? ,Is a greater risk for infection a side effect of of taking terbinafine? Is it ok to continue to take them together?