FDA Approves 12.5 mg Chlorthalidone Tablets for Hypertension

The US Food and Drug Administration (FDA) has approved 12.5 mg chlorthalidone tablets (HemiClor), targeted to lower blood pressure in the treatment of adults with hypertension.1

Announced by PRM Pharma, LLC, on May 6, 2025, 12.5 mg chlorthalidone tablets will be available in pharmacies nationwide beginning this month, providing access to a guideline-recommended formulation supported by the American College of Cardiology (ACC) and American Heart Association (AHA).

“Chlorthalidone has played a key role in hypertension treatment strategies for decades,” said William B. White, MD, a professor emeritus at the University of Connecticut and past president of the American Society of Hypertension, in a statement.1 “Having access to a 12.5 mg dose in the US may offer clinicians additional flexibility when initiating therapy and aligns with current treatment recommendations for many adult patients with stage 1 or stage 2 hypertension.”

Reducing blood pressure can lower the risk of fatal and nonfatal cardiovascular events, including stroke and myocardial infarction. Evidence from randomized controlled trials has demonstrated the benefit of antihypertensive drugs across various pharmacologic classes, including chlorthalidone.1

Chlorthalidone, a thiazide-like diuretic, was labeled the preferred diuretic in the 2017 ACC/AHA Guidelines for Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults, given its apparent cardiovascular outcome benefits and prolonged half-life.2 In the ALLHAT and SHEP trials, stepped-care treatment strategies beginning with 12.5 mg of chlorthalidone effectively reduced the risk of cardiovascular events.3,4

In the release, PRM Pharma indicated these data supported the use of 12.5 mg as the recommended starting dose in current hypertension treatment guidelines when initiating antihypertensive therapy or as an add-on therapy for additional blood pressure reduction.1

With a low-dose chlorthalidone tablet option, alongside 25 and 50 mg doses, the company indicated clinicians may be able to individualize therapy for hypertension and lower the risk of drug-related side effects. Chlorthalidone has been linked to dose-related metabolic adverse effects, including hypokalemia and hyperuricemia, making a lower starting dose attractive to lower these risks when initiating treatment.

“We are proud to introduce HemiClor as a new treatment option for adults with hypertension,” said Joseph T. McDevitt, president and chief executive officer of PRM Pharma, LLC, in a statement.1 “Our mission is to address unmet clinical needs by developing low-dose pharmaceutical products that support evidence-based care. Lower effective doses may offer a more individualized approach to initiating therapies, particularly for elderly patients who are more susceptible to dose-related adverse effects.”

References

1. PRM Pharma L. FDA approves new, low-dose chlorthalidone for the treatment of hypertension in adults: HemiclorTM (12.5 mg chlorthalidone). PR Newswire: press release distribution, targeting, monitoring and marketing. May 6, 2025. Accessed May 6, 2025. https://www.prnewswire.com/news-releases/fda-approves-new-low-dose-chlorthalidone-for-the-treatment-of-hypertension-in-adults-hemiclor-12-5-mg-chlorthalidone-302446420.html.

2. Whelton PK, Carey RM, Aronow WS, et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines. Circulation. 2018;138(17):e426-e483. doi:10.1161/CIR.0000000000000597

3. The ALLHAT Officers and Coordinators for the ALLHAT Collaborative Research Group. Major Outcomes in High-Risk Hypertensive Patients Randomized to Angiotensin-Converting Enzyme Inhibitor or Calcium Channel Blocker vs Diuretic: The Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial (ALLHAT). JAMA. 2002;288(23):2981–2997. doi:10.1001/jama.288.23.2981

4. Prevention of Stroke by Antihypertensive Drug Treatment in Older Persons With Isolated Systolic Hypertension: Final Results of the Systolic Hypertension in the Elderly Program (SHEP). JAMA. 1991;265(24):3255–3264. doi:10.1001/jama.1991.03460240051027