Lithium directly affects which ion ?

Ans. is 'a' i.e., Sodium Diuretics (paicularly thiazides) decrease the renal excretion of lithium and thus may result in toxicity. This is due to increased reabsorption of Na' and lithium ions (as a compensatory response to excessive loss of Nat). Interactions of lithium 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.