This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Unknown
What happens to lithium levels in blood when used with hydrochlorothiazide? 
Select and explain. 
A. Blood levels of lithium rise, B. Blood levels of lithium decrease, C. Blood levels of hydrochlorothiazide rise, D. Blood levels of hydrochlorothiazide fall
A: Blood levels of lithium rise
Answer: A: Blood levels of lithium rise 
Explanation: (Refer: Katzung’s Basic and Clinical Pharmacology, 10thedition,pg no: 244)

Thiazide diuretics act by inhibiting the NaCl channel of DCT resulting in increased solute loss in urine without affecting the negative free water clearance.
This loss of solutes especially sodium is compensated by increased reabsorption in the PCT.
Renal lithium excretion is affected by changes in the sodium balance.
Drugs causing renal loss of sodium causes increased reabsorption of lithium in PCT.
Eg: ACE inhibitors, AT2 receptor blockers, NSAIDS, Thiazides