Methods for treatment of a pathological condition caused by oxidative stress in a patient comprise administering to the patient a mixed metal complex of a compound of Formula I, or a salt thereof, in an amount effective to reduce the oxidative stress. Pharmaceutical compositions are formed by suspending or dissolving a mixed metal complex of a compound of Formula I, or a salt thereof, in a liquid medium, optionally with one or more physiologically acceptable excipients. The mixed metals comprise calcium and manganese in a molar ratio of calcium to manganese in the range of 1-10:wherein X, R1, R2, R3, and R4 are as defined herein.
