hai doctor ,

I am diagnosed with lymph node TB and the doctor advised me to take combutol(800mg)+ solonex(300mg) and Levofflox (750)for the past 3 months(Rifamycin is allergic to me). For the past three months I and taking this medication with out any serious side effects. Now the doctor advise me to take combutol(800mg)+ solonex(300mg) for 2 months. Is it is safe to use the combutol for such a long period?