Below are messages returned in the comment field from the approximate match function. A detailed explanation follows each message.

Ambiguous top score (too many entries)

The processing identified a large number of terms in many different concepts with the same top score. When this happens, the algorithm declares the results as ambiguous, and no entries are returned.

Input truncated to xxxx characters

The input string is too large to be processed, and the string is truncated to the number of characters specified for processing.

No drugs identified

The words in the search term contain no words recognized as drugs by RxNorm.

Non RxNorm concepts omitted (option=1)

The user specified that only terms from RxNorm concepts be returned.

Replaced xxxx with yyyy

Example:

Replaced benaz with benazepril

Messages of this form indicate an unknown word is a shortened form of a known drug. In the example, the word "benaz" was not known, but was expanded to the drug "benazepril".

Spelling substitution: xxxx for yyyy

Example:

Spelling substitution: amlodipine for amiodipine

Messages of this form indicate an unrecognized word was replaced with a spelling suggestion. In the example, the word "amiodipine" was not found, and a spelling suggestion of "amlodipine" was substituted. Spelling substitutions will decrease the total score as they are considered partial matches.

Split token xxxx into multiple tokens

Example:

Split token capcr24 into multiple tokens

Messages of this form indicate an unrecognized word containing numbers and letters is split into multiple words comprising all number and all letter words. In the example, "capr24" is split into "capr" and "24".

Trying xxxx as drug

Example:

Trying bulgaricus as drug

Messages of this form indicate that a word was found in the data set, but is not identified as an RxNorm drug. However, it is being used as though it were a drug because no drugs were found in the search term. In the example, "bulgaricus" is a word in the RxNorm data set, but not identified as an ingredient or brand name. But because there are no drugs identified in the search term, the approximate match algorithm uses bulgaricus as the drug.