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Frequently Asked Questions for Pharmacists on NTI Drugs

Q: Must a drug be rated AB in FDA’s Orange Book to be used in product selection in North Carolina?

A: The North Carolina Product Selection Law does not refer to the Orange Book rating published by the Food and Drug Administration. That rating can be useful in determining what is used in product selection, but it is not necessarily determinative. The ultimate decision on equivalency is up to the pharmacist.


Q: Which drugs are included on the NTI List?

A: As of January 27, 2009 the list is:

Carbamazepine [Tegretol, various others]
Digoxin [Lanoxin and others]
Levothyroxine sodium tablets
[Levothroid, Levoxyl, Synthroid, various others
Lithium [Eskalith, Cibalith]
Phenytoin [Dilantin]
Procainamide Hydrochloride
Tacrolimus [Prograf] - see January 27, 2009 letter from Secretary of Health & Human Services
Theophylline [Elixophyllin, Slo-Phyllin, Slo-bid Gyrocaps, Theochron, Theo-Dur, Theo-24, Uniphyl,]
Warfarin sodium tablets [BMS Warfarin, Coumadin, Warfarin]


Q: Does an AB Rating from FDA change how a prescription for a Narrow Therapeutic Index drug is handled?

A: It has come to the Board’s attention that one manufacturer has received an AB Rating for their Levothyroxine product.

Pharmacists should be aware that the Narrow Therapeutic Index Drug concept is found in the state’s Product Selection Law, G.S. 90-85.27 and .28. Levothyroxine qualifies as an NTI drug under this statute which means that pharmacists need to get the documented consent of the prescriber and the patient before switching manufacturers on refills.

An AB Rating by the Food and Drug Administration in its Orange Book publication does not change the application of the NTI rule as noted above.


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