The FDA has approved 12.5 mg chlorthalidone tablets (HemiClor, PRM Pharma, LLC) for the treatment of hypertension in adults to lower blood pressure.
Several studies sponsored by the National Heart, Lung, and Blood Institute have demonstrated that stepped-care treatment strategies, which often began with 12.5 mg of chlorthalidone, were effective in reducing the risk of cardiovascular events.1,2 These findings support the use of 12.5 mg as the recommended starting dose in current hypertension treatment guidelines, either to initiate antihypertensive therapy or to serve as add-on therapy when additional blood pressure reduction is needed.3,4
Until now, only higher-dose chlorthalidone tablets have been available in the United States.
“Chlorthalidone has played a key role in hypertension treatment strategies for decades,” William B. White, MD, professor emeritus at the University of Connecticut School of Medicine and past president of the American Society of Hypertension said in a press release about the approval.5 “Having access to a 12.5 mg dose in the United States 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.”
References
- ALLHAT Collaborative Research Group. Major outcomes in high-risk hypertensive patients randomized to ACE inhibitor or calcium channel blocker vs diuretic. JAMA. 2002;288(23):2981-2997. doi:10.1001/jama.288.23.2981
- SHEP Cooperative Research Group. Prevention of stroke by antihypertensive drug treatment in older patients with isolated systolic hypertension. JAMA. 1991;265(24):3255–3264.
- Whelton PK, Carey RM, Aronow WS, et al. 2017 ACC/AHA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults: Executive Summary. Hypertension. 2018;71(6):1269-1324. doi:10.1161/HYP.0000000000000066
- James PA, Oparil S, Carter BL, et al. 2014 Evidence-Based guideline for the management of high blood pressure in adults. JAMA. 2014;311(5):507–520. doi:10.1001/jama.2013.284427
- PRM Pharma. FDA Approves New, Low-Dose Chlorthalidone for the Treatment of Hypertension in Adults: HemiClor™ (12.5 mg chlorthalidone) [press release]. May 6, 2025. Accessed July 10, 2025. 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#xd_co_f=Y2M4YTVkNGQtMjg2MS00ZDk5LTgxNGUtZjJhMmFmMDJmZTE2~