Bentiromide is not available in the United States or Canada; it was withdrawn in the US in October 1996.
[2] Headache and gastrointestinal disturbances have been reported in patients taking bentiromide.
It is broken down by the pancreatic enzyme chymotrypsin, yielding p-aminobenzoic acid (PABA).
The amount of PABA and its metabolites excreted in the urine is taken as a measure of the chymotrypsin-secreting activity of the pancreas.
The resulting L-amide is selectively hydrolyzed by sequential use of dimsyl sodium (NaDMSO) and dilute acid to give bentiromide (4).