<prompt> Which among the following is an early sign of magnesium toxicity? NOT RELATED-MEDICINEDepression of deep tendon reflexesRespiratory depressionCardiac arrestDecreased urine output  <response>: Ref:Drug Facts and Comparisons 2010127 Knee jerk patellar reflex stas diminishing at plasma magnesium concentration of 4mEqL and disappears at 10mEqL, where respiratory paralysis is a potential hazard. 