IUTBAP (I used to be a pharmacist).
One of the things we studied were drug interactions.
Basically pharmacists are more qualified to know these interactions, because they studied pharmacology, as well as pharmaceutics (how drugs are presented, what each form's method of spreading to the affected area(s) are, ...etc.)
The clinical pharmacy movement was started back several decades ago, so doctors would diagnose, then pharmacists would prescribe together with the doctors, taking into account many things, like other patient health issues, drug interactions, ...etc.
But, this will not happen, because big pharma markets to doctors so they prescribe their brand over the competition.
Sad to see the state of affairs status quo as they were in the early 80s.