Most diuretics raise uric acid levels, which is a real problem if you have gout or are already running high. The short answer: no commonly prescribed diuretic is truly neutral on uric acid, but SGLT2 inhibitors (a newer class of medication with diuretic properties) actually lower it. Among traditional diuretics, the differences between classes are smaller than many people expect.
Why Most Diuretics Raise Uric Acid
Your kidneys filter uric acid out of the blood and then reabsorb most of it back through specialized transporters in the kidney tubules. The most important of these is a protein called URAT1. Diuretics interfere with this system in two ways. First, they reduce blood volume, which concentrates uric acid in the blood and triggers the kidneys to reabsorb more of it. Second, some diuretics directly compete with uric acid for secretion into the urine through another transporter called hNPT4, effectively blocking one of the routes uric acid uses to leave the body.
This means the problem isn’t limited to one type of diuretic. Thiazides, loop diuretics, and thiazide-like drugs all raise uric acid through overlapping mechanisms.
How Each Diuretic Class Affects Uric Acid
Thiazides and Thiazide-Like Diuretics
Hydrochlorothiazide (HCTZ) is the most commonly prescribed thiazide and one of the biggest offenders for raising uric acid. In comparative trials, HCTZ increased serum uric acid by roughly 26%. Indapamide, sometimes marketed as a gentler alternative, performed almost identically, raising uric acid by about 27% in head-to-head testing. The 2020 American College of Rheumatology gout guidelines conditionally recommend switching off hydrochlorothiazide entirely if you have gout and an alternative blood pressure medication is available.
Loop Diuretics
Furosemide and bumetanide raise uric acid through both volume depletion and direct interaction with the hNPT4 secretion pathway. Torsemide, another loop diuretic sometimes thought to be easier on uric acid, actually increased levels by 0.4 mg/dl over 30 days in a recent comparative study, while furosemide slightly decreased them by 0.2 mg/dl. That finding surprised researchers, and it was likely related to differences in how aggressively each drug was dosed. The bottom line: no loop diuretic reliably spares uric acid.
Potassium-Sparing Diuretics
Spironolactone is sometimes assumed to be safer for uric acid because it works differently from thiazides and loop diuretics. But clinical data tells a different story. In patients with chronic kidney disease, spironolactone increased serum uric acid levels. Amiloride and triamterene are weaker diuretics with less data on uric acid specifically, but neither has been shown to reliably avoid the problem.
Carbonic Anhydrase Inhibitors
Acetazolamide works by a completely different mechanism than other diuretics and is sometimes used to help dissolve uric acid kidney stones by making urine more alkaline. However, it’s a weak diuretic rarely used for blood pressure or fluid management, so it’s not a practical substitute for a thiazide or loop diuretic in most situations.
SGLT2 Inhibitors: A Diuretic That Lowers Uric Acid
SGLT2 inhibitors are the closest thing to a diuretic that actively reduces uric acid. Originally developed for type 2 diabetes, drugs in this class (like empagliflozin and dapagliflozin) block glucose reabsorption in the kidneys, which pulls extra water and sodium into the urine, creating a mild diuretic effect. They’re now widely prescribed for heart failure and kidney protection regardless of diabetes status.
The uric acid benefit is significant. In clinical studies, dapagliflozin dropped plasma uric acid from 5.5 to 4.6 mg/dl. Empagliflozin reduced it by about 1.0 mg/dl. Unlike traditional gout medications that slow uric acid production, SGLT2 inhibitors work by increasing how much uric acid the kidneys excrete. The glucose flooding into the urine appears to interfere with URAT1, the same transporter that normally pulls uric acid back into the blood. The more glucose in the urine, the more uric acid comes along with it.
This makes SGLT2 inhibitors particularly useful for people who need both a mild diuretic effect and uric acid control, especially those with heart failure, diabetes, or chronic kidney disease where these drugs are already indicated.
Losartan: Not a Diuretic, but Worth Knowing About
Losartan is a blood pressure medication (an angiotensin receptor blocker, not a diuretic) that has a unique side benefit: it directly blocks URAT1 in the kidneys, lowering uric acid levels. This effect is specific to losartan. Other drugs in the same class, like candesartan, do not lower uric acid at all. The ACR gout guidelines conditionally recommend choosing losartan preferentially when patients with gout need blood pressure treatment.
For someone taking a thiazide primarily for blood pressure and not for fluid overload, switching to losartan can address both the blood pressure and the uric acid problem at once.
Practical Options if You Need a Diuretic
If you genuinely need a diuretic for fluid retention or heart failure, eliminating the uric acid increase entirely with a traditional diuretic isn’t realistic. Your options come down to managing the tradeoff:
- Switch off the diuretic if possible. If you’re on a thiazide purely for blood pressure, alternatives like losartan or calcium channel blockers don’t raise uric acid.
- Consider an SGLT2 inhibitor. If you have heart failure, diabetes, or chronic kidney disease, these provide mild diuretic action while actively lowering uric acid.
- Add uric acid-lowering therapy. If you must stay on a thiazide or loop diuretic, medications that reduce uric acid production can counteract the increase. Studies show diuretic users typically need higher doses of these medications to reach target uric acid levels.
- Use the lowest effective diuretic dose. The uric acid increase is dose-dependent. Lower doses cause smaller increases.
A historical note worth mentioning: a drug called tienilic acid (ticrynafen) was once marketed as a diuretic that actively lowered uric acid. It was pulled from the U.S. market in 1979, just months after launch, because it caused severe liver damage in about 1 in 1,000 patients, with a 10% fatality rate among those who developed jaundice. No replacement uricosuric diuretic has been developed since.