I suppose the usual starter dose is 1 azithromycin (500 mg), 1 ethambutol (400 mg), and 2 rifampin (rifabutin 150 mg each) 3x/week. That said, given my reactions or lack of reactions over the last six months, my doctor has had to adjust the dosages a couple of times. I'm currently taking 1-3-2, but I anticipate yet another modification soon.