Many patients arrive at the emergency room or physician office not
knowing the names of their medications.  One physician may be treating a
heart condition and another physician orders the same medication under
another trade name to treat the same condition. Since the two medications
have different names, both medications taken together can be life threatening.
If both medications were filled at the same pharmacy, the duplication may
have been detected.

Many patients visit multiple pharmacies
as well as multiple 
physicians. Medications taken incorrectly can result in a serious (and costly) condition.

Complications have also resulted from patients taking the wrong medication.

That "little white tablet"
that Mrs. Jones was taking for diarrhea was actually her heart tablet. (could be a fatal mistake)