unfortunately no one can read his handwriting
An ancient tradition in the field of medicine. My father was a doctor so I speculate with a degree of certainty that medical schools require at least a semester of study in illegible handwriting.
Only pharmacists can read it. I believe their tradition hails back to the Oracles of Delphi, the seers who entered caves where drug like vapors emanated from the earth allowing them to prophesy the future. And read prescriptions.