A patient on lithium therapy developed hypertension

A patient on lithium therapy developed hypertension. He was started on Thiazide for hypertension. After a few days, he developed coarse tremors and other symptoms suggestive of lithium toxicity. What is the probable mechanism of interaction?

A. Thiazide increases the tubular reabsorption of lithium

B. Thiazide inhibits the metabolism of lithium

C. Thiazides act as an add on the drug to lithium

D. All of the above

A. Thiazide increases the tubular absorption of lithium
Explain:- Drug Interaction: Diuretics + Lithium = Decreased excretion—rise in Lithium level - toxicity; Diuretics (thiazide, furosemide) by causing Sodium ion loss to promote proximal tubular reabsorption of Sodium ion as well as Lithium ion → plasma levels of lithium rise. Potassium-sparing diuretics cause milder Lithium ion retention. Management: Reduce dose of lithium and monitor level.