Does Morphine Causes Rapid Fluctuation In Blood Pressure?

Husband has MSA-C since 2003. Suffered 2 Minor heart attacks last year and breathing issues. Presently under hospice care (for 1 year already) and breathing has been labored for weeks. They are recommending morphine and I question if it will be problematic and slow the breathing down and effect the blood pressure. His BP changes from 64/47 to 235/157 within 45 minutes. He is wheelchair bound and totally dependent. Looking for answers and not much on line. Thank you.