Table 4.

Standard immunosuppressants used in different CTD-ILD

CTD	Drugs	Remarks
SSc-ILD	Mycophenolate 2–3 g daily orally	Pulse CYC doses are associated with lesser toxicity but most trials have used daily oral doses Rituximab (2 g induction as given below) and tocilizumab (162 mg subcutaneous weekly) are second-line agents
	Cyclophosphamide Oral: 2–3 mg/kg body weight/day Pulse: 600/m2 iv every month For a maximum of 6 months
	Nintedanib may be added to either of the above at 150 mg 12 hourly orally
RA-ILD	Rituximab 1 g intravenous infusion 2 weeks apart	Methotrexate and leflunomide may have a role especially in early minimally symptomatic disease A proportion of RA-ILD do not progress or progress very slowly even without treatment
	Azathioprine 2–3 mg/kg body weight/day orally
	Cyclophosphamide (as mentioned above)
	Mycophenolate 2–3 g daily orally
Myositis-ILD	High doses steroid (1 mg/kg body weight of prednisolone) with one of the following: Rituximab 1 g 2 weeks apart (Or 375 mg/m2 body surface area weekly × 4 weeks)	Rapidly progressing disease: Pulse steroids with one or two of the following: Rituximab, cyclophosphamide, tofacitinib, or intravenous immunoglobulin
	Mycophenolate 2–3 g daily orally
	Azathioprine 2–3 mg/kg body weight/day
	Cyclophosphamide (as mentioned above)

Dosages may need adjustment for hepatic or renal dysfunction

CTD connective tissue disorders, RA rheumatoid arthritis, ILD interstitial lung disease