Furosemide × Hydrochlorothiazide

Sequential nephron blockade: furosemide acts at the loop of Henle, the thiazide at the distal tubule. Additive diuresis in fluid retention resistant to a single diuretic.

Weakness, dizziness, thirst, reduced urine output, rising creatinine. In older patients, fall risk from orthostatic hypotension. Weakness, muscle cramps, fatigue, palpitations, arrhythmia (particularly dangerous with digoxin). Symptoms appear at potassium below 3.5 mmol/L.

Use only as short courses (3–7 days) with daily weight and creatinine every 1–2 days. Potassium, sodium, magnesium every 2–3 days. When weight loss reaches 1–1.5 kg/day, reduce diuresis pace — return to a single diuretic. For sustained need, consider an SGLT-2 inhibitor or tolvaptan.