Major
Hydrochlorothiazide × Lithium
Thiazide diuretics×Psycholeptics. Lithium
Mechanism
Hydrochlorothiazide increases sodium and lithium reabsorption in the distal tubule. Lithium plasma concentration rises 25–40% (up to 100% in some patients). Lithium toxicity develops within 1–2 weeks.
Symptoms
Tremor, nausea, diarrhea, confusion; in severe cases seizures and coma.
Management
For hypertension in a lithium patient, choose another class: calcium channel blocker (amlodipine) or a potassium-sparing diuretic with caution. If thiazide is required, halve lithium and check level on days 5–7 and at 2 weeks.
Check the full regimen, not just this pair
Opens the checker with these two drugs prefilled. Add the rest of the regimen and recompute additive risks.