Problem: A client comes to the clinic for serum lithium levels. The level is subtherapeutic at 0.1 mEq/L (therapeutic range: 0.6-1.2 mEq/L). Which is the likely cause of the low lithium level? Select all that apply. The dosage may need to be increased. The client may be taking medication that interacts with this drug. The client has a low serum sodium level. The client may not be taking their medication as directed. The dosage needs to be decreased.