Losartan and Metolazone interaction
Losartan and Metolazone: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Metolazone label · effective 2026-01-15
Other Antihypertensive Drugs When metolazone tablets, USP, are used with other antihypertensive drugs, particular care must be taken to avoid excessive reduction of blood pressure, especially during initial therapy.
Dosage adjustments of other antihypertensives may be necessary.
Other Antihypertensives When metolazone tablets, USP, are used with other antihypertensive drugs, care must be taken, especially during initial therapy.
From the Losartan (COZAAR) label · effective 2026-01-20
Hypotension in Volume- or Salt-Depleted Patients In patients with an activated renin-angiotensin system, such as volume- or salt-depleted patients (e.g., those being treated with high doses of diuretics), symptomatic hypotension may occur after initiation of treatment with COZAAR.
NSAIDs: Increased risk of renal impairment and reduced diuretic, natriuretic, and antihypertensive effects.
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) Including Selective Cyclooxygenase-2 Inhibitors (COX-2 Inhibitors) In patients who are elderly, volume-depleted (including those on diuretic therapy), or with compromised renal function, coadministration of NSAIDs, including selective COX-2 inhibitors, with angiotensin II receptor antagonists (including losartan)…
Renal Function Deterioration Changes in renal function including acute renal failure can be caused by drugs that inhibit the renin-angiotensin system and by diuretics.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.