Magnesium inhibits the hypertensive but not the cardiotonic actions of low-dose epinephrine.
Prielipp RC, Zaloga GP, Butterworth JF, Robertie PG, Dudas LM, Black KW, Royster RL. Magnesium inhibits the hypertensive but not the cardiotonic actions of low-dose epinephrine. Anesthesiology. 1991 Jun; 74(6):973-9.