The nurse is assessing therapeutic blood levels for a client receiving lithium (Lithobid). The nurse should recognize which of the following levels as toxic for this drug?

A. Levels in this range are generally considered therapeutic for lithium. B. Levels in this range are typically below the therapeutic range for lithium. C. Lithium levels in the range of 1.5 mEq/L to 2 mEq/L are considered toxic and require intervention. D. Levels in this range are generally within the therapeutic range for lithium.