Dibucaine Number.

Dibucaine is a local anesthetic.

Dibucaine inhibits 80% of the normal Pseudocholinesterase enzyme and 20% of the Atypical enzyme.

The number is determined by measuring the percentage of Pseudocholinesterase enzyme that remains unchanged in the blood of individuals administered a standard dose of Dibucaine intravenously.

Normal Dibucaine number is 70-80% i.e 70-80%of normal enzyme is inhibited by Dibucaine.
If there is a point mutation in the enzyme making it a Atypical Pseudocholinesterase then Dibucaine will not be able to inhibit it and the number will decrease.

This number is used to measure the activity of Atypical Pseudocholinesterase,and to assess the likely hood of prolonged apnea after succinylcholine administration.

Sodium Fluoride can also be used in place of Dibucaine.