The drugAllergyByProductID(...) function is used to see if a drug will interact with an allergy.  The result of drugAllergyByProductID(...) is a boolean.  If true then the drug and allergy will interact otherwise false. 

Syntax:
drugAllergyByProductID( productID, allergy )
productID.drugAllergyByProductID( allergy ) 

Parameter Description
productID

ProductID for the drug from the "medName" lookup.

allergy

Allergy from the "drugAllergy" lookup.