A 28-year-old woman presents to your pulmonary clinic with worsening shortness of breath. She has been taking sildenafil, iloprost, and diuretics but they did not improve her condition. She would like to try a new medication that acts by blocking endothelin receptors in the pulmonary bed. As part of patient education, which of the following is the right information to give to this patient about endothelin receptor antagonists?