Could Sensipar And Metoprolol Be The Cause For Shortness Of Breath?

My husband has stage 3 kidney disease, hyperparathyroidism, recurring gout. On a daily basis he takes Colchicine, Lasix, Metoprolol Tartrate, Minoxidil, Uloric, and now Sensipar. He takes Zemplar 3x/wk, Ergocalciferol 1x/week and Procrit once a month as needed. Since the doctor put him on Zemplar (before Thanksgiving) he has been having problems with shortness of breath. The SOB occurs only occasionally with physical exertion, and it also occurs sporadically at night right before he is about to go to bed. He will have to sit up on the side of the bed for up to an hour before he can go to sleep. During this time he also has a dry cough. After researching all of this and drug interactions, I found that Sensipar and Metoprolol can interact, causing the side effects of Metoprolol to intensify and increasing the amount of Metoprolol in your system. Also, the two drugs interacting together is on a list of drugs that can cause heart failure when taken simultaneously. Do you think that the Sensipar and Metoprolol together could be causing the SOB? He takes both at night at the same time. He is scheduled for numerous tests later this month, including a Thallium stress test, echocardiogram, and carotid scan.