How do you approach the use of endothelin receptor antagonists in patients with scleroderma renal crisis and hypertension refractory to maximum ACE inhibition and calcium channel blockers?

There is pathologic evidence of endothelin being increased in the renal biopsies of patients with scleroderma renal crisis. There has been one small prospective open study where endothelin receptor antagonists were used in addition to ACE inhibitors in some refractory patients and compared to historical controls (1). While the treatment seemed safe and possibly additive, because of small numbers there was no clear answer as to its effectiveness. Further study is really indicated before the use of ERA's can be recommended to be added to ACE inhibitors for treatment of renal crisis.

The question of what is refractory renal crisis also needs to be defined. Many patients' blood pressure and MAHA respond to ACE inhibitors but their kidney dysfun...