Described herein is a new antidote for the rapid elimination of carbon monoxide from hemoglobin, including brain, heart, and red cell hemoglobin. The disclosed therapy involves the use of modified human globins, particularly neuroglobins modified at residue 64 and cytoglobins modified at residue 81, which bind carbon monoxide with extremely high affinity. The monomeric mutant globins are infused into blood, where they rapidly and irreversibly sequester carbon monoxide, and thus limit toxic effects of carbon monoxide on cellular respiration and oxygen transport and utilization.