Which of the following antihypeensive drugs should not be used in a patient on Lithium in order to prevent Lithium Toxicity.
Clonidine
Beta blockers
Calcium Channel Blockers
Diuretics
Ans is 'd' i.e. Diuretics Interactions of lithium 1. Diuretics (thiazide, furosemide) by causing Na+ loss promote proximal tubular reabsorption of Na+ as well as Li - Plasma level of lithium rises. Tetracyclines, NSAIDs and ACE inhibitors cause lithium retention. Lithium tends to enhance insulin/sulphonylurea induced hypoglycemia (lithium has insulin like action on glucose metabolism). Lithium inhibits the action of ADH on distal tubules --> causes nephrogenic DI. Lithium reduce thyroxine synthesis by interfering iodination of tyrosine.