Fig. 1

Distinct pharmacologic activities of the R- and S-enantiomers of ketorolac. Ketorolac is a chiral molecule administered as a 1:1 racemic mixture of S- and R-enantiomers, chemical structures are from PubChem. The arrow indicates the location of the chiral center. R-ketorolac inhibits Rac1 and Cdc42 with 50% inhibitory concentration (IC₅₀) values of 0.57 and 1.07 μM for Rac1 and Cdc42, respectively as assessed in cell-based assays [23]. R-ketorolac displays negligible activity against cyclooxygenases (COX) 1 or 2 [26, 29]. S-ketorolac is considered the active component for ketorolac’s FDA-approved indication in pain management with selective activity against COX enzymes [29] and minimal activity against Rac1 and Cdc42 as measured in ovarian tumor cells [27]