ADRs are identified based on the untoward effect and causality assessment.
Moreover, All good references had already define maximum possible ADRs for a particular drug including those in post marketing surveillance. One can refer to Micromedix or Lexicomp.
Drug interactions are also identified but, are a highly patient specific phenomena which cannot be applied to all patient population receiving such drugs.
Mostly in clinical setting such interactions are not identified purely based on their pharmacokinetic profile but also on patients symptoms and physiological conditions.
For example digoxin and a diuretic may cause arrhythmia in one patient and may not cause the same in another.
All or any drug interaction should only be identified and communicated only when they are clinically significant or altering patients condition.