Generic Product Identifier


The Generic Product Identifier is a 14-character hierarchical classification system that identifies drugs from their primary therapeutic use down to the unique interchangeable product regardless of manufacturer or package size. The code consists of seven subsets, each providing increasingly more specific information about a drug available with a prescription in the United States.
The first six characters of the GPI define the therapeutic class code, the next two pairs the drug name, and the last four define route, dosage or strength. For example GPI 58-20-00-60-10-01-05 is for the drug nortriptyline HCl cap 10 mg and can be further classified as follows:
GPICodingExample
58Drug groupAntidepressants
58-20Drug classTricyclic agents
58-20-00Drug sub-class
58-20-00-60Drug nameNortriptyline
58-20-00-60-10Drug name extensionHydrochloride
58-20-00-60-10-01Dosage formCapsule
58-20-00-60-10-01-05Strength10 mg

Alternate drug classification systems include the AHFS Drug Information brand run by the American Society of Health-System Pharmacists and First DataBank's Generic Sequence Number.
Wolters Kluwer provides a database under the Medi-Span brand called Medispan Electronic Drug File that links this code to other prescription drug classification codes commonly used for payment and analysis in the United States Health Care System, as well as embedded drug information like adverse drug effects.