Initiate therapy with reduced starting doses (30-80% of standard starting dose) if standard starting dose is ≥2 mg/kg/day. If starting dose is already below standard starting dose, dose reduction might not be necessary. During therapy, adjust the doses of azathioprine based on the degree of myelosuppression and disease-specific guidelines. It usually takes at least 2-4 weeks of stable dosing to reach steady state after each dose adjustment.