Oxfenicine is a CPT-1b-specific inhibitor. It must be transaminated to its active form, 4-hydroxyphenyl-glyoxylate, which is competitive with carnitine, preventing the formation of acylcarnitine. Because CPT-1b shows the highest sensitivity to 4-hydroxyphenyl-glyoxylate, inhibition of fatty acid oxidation by oxfenicine takes place selectively in those tissues that express this CPT isoform. It may be effective for treating noninsulin-dependent diabetes mellitus which is characterized by elevated fatty acid levels and obesity. In 1980 it was also tested in preclinical models of angina pectoris and ischemia.