More than a decade ago the internist who was supervising my non-functioning thyroid and was one of the few doctors in this region conducting research on the side effects of many medications in combination with thyroid substitution medication told me to avoid aspirin products. He also said take it half an hour before you eat breakfast, so first thing upon awakening.
Aspirin would not harm me but would affect the efficacy of Thyrex.
You cannot imagine how many times I've had to mention this to various doctors. Also at this last surgery. They had written on my chart "allergic to aspirin". I made them change it. And I told several of the docs who asked me why I wanted to have it changed, about Dr. O's research from 20 years ago.
A distant cousin, a doctor, also internist, at first very sceptic of this, now instructs his students about this.
Sometimes it takes decades until some medical news gets to our doctors.