mustang68 I had the same problem when my dose was increased from 5 to 10 mg. I am not very consistent day to day. Some days are great with no symptoms while others have me so low energy it's hard to even get out of the chair. I have had that inconsistency all along since starting Camzyos, but my good days outnumbered the others on the 5 mg. Not so on the 10 mg. I was not only more tired, but had worsening shortness of breath, and my low energy days outnumbered the good days. After my caridologist returned me to 5 mg, I definitely improved. My echos were comparable with similar gradients on the 5 mg as on the 10 mg dose, but since I felt so much better on the 5 mg, he is keeping me at that dosage. Hope that helps.