Lithium's effects are two-fold: the first effect is that it may be absorbed instead of Na+. If it is prescribed, the lithium dose is typically cut by half, because thiazide diuretics boost lithium levels in the blood and could cause toxicity. Diuretics that act at the distal renal tubule, (for example, hydrochlorothiazide [ Hydrodiuril ], spironolactone [ Aldactone ], triamterene [ Dyrenium ; Dyazide, Maxzide]), can increase blood concentrations of lithium. The following medications can increase the levels and effects of lithium: Diuretics, such as: hydrochlorothiazide (Microzide®), furosemide (Lasix®), bumetanide (Bumex®), torsemide (Demadex®), acetazolamide (Diamox®), chlorthiazide (Diuril®), and chlorthalidone (Thalitone®) It's also important to monitor for imbalances of electrolytes, the … Diuretics (water pills) should be used cautiously in patients receiving lithium. There have been many reports of lithium toxicity in patients coadministered thiazide diuretics, and studies looking at drug levels commonly report 20% to 40% increases in plasma lithium levels. The thiazide diuretic hydrochlorothiazide is one of these. Lithium plasma concentrations are known to be increased with concurrent use of diuretics—especially loop diuretics (such as furosemide) and thiazides—and non-steroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen.