The Medical Letter on Drugs and Therapeutics
FROM
ISSUE
1733
In Brief: Low-Dose Chlorthalidone (HemiClor) for Hypertension
Download PDF:   US English
Med Lett Drugs Ther. 2025 Jul 21;67(1733):118   doi:10.58347/tml.2025.1733e
Disclosures
Principal Faculty
  • Mark Abramowicz, M.D., President has disclosed no relevant financial relationships.
  • Jean-Marie Pflomm, Pharm.D., Editor in Chief has disclosed no relevant financial relationships.
Objective(s)
Upon completion of this activity, the participant will be able to:
  1. Discuss the efficacy of the new 12.5-mg dose of chlorthalidone (HemiClor) for treatment of hypertension.
 Select a term to see related articles  atenolol   azilsartan   chlorthalidone   HemiClor   hypertension   Tenoretic   Thalitone 

The FDA has approved a 12.5-mg tablet formulation of the thiazide-like diuretic chlorthalidone (HemiClor – Ingenus) for treatment of hypertension. Chlorthalidone has been available for years in 15-, 25-, and 50-mg tablets (Thalitone, and generics) and in fixed-dose combinations with azilsartan medoxomil (Edarbyclor) and atenolol (Tenoretic, and generics).1,2

CHLORTHALIDONE — Chlorthalidone is more potent than the thiazide diuretic hydrochlorothiazide (HCTZ) and it has a longer half-life. Chlorthalidone and HCTZ appear to be similarly effective in improving outcomes in patients with hypertension,3-5 but chlorthalidone is more likely to cause hypokalemia. Current guidelines recommend chlorthalidone at a dose of 12.5-25 mg once daily for treatment of hypertension.6

A CLINICAL STUDY — FDA approval of the 12.5-mg formulation was based on data from an 8-week double-blind trial in 1714 adults with hypertension who were randomized to receive one of six fixed-dose combinations of azilsartan medoxomil and chlorthalidone or the individual components alone. Monotherapy with chlorthalidone 12.5 mg was similar in efficacy to the 25-mg dose with fewer adverse effects.7

COST — The wholesale acquisition cost (WAC) of a 30-day supply of HemiClor is $30; cutting a 25-mg tablet of generic chlorthalidone in half costs much less ($3 for 15 25-mg tablets) but may be difficult for some patients.8

CONCLUSION — The new low-dose formulation of chlorthalidone (HemiClor) offers a convenient way to administer a 12.5-mg dose without having to split a higher-strength tablet.

  1. Edarbyclor: an ARB/chlorthalidone combination for hypertension. Med Lett Drugs Ther 2012; 54:17.
  2. Drugs for hypertension. Med Lett Drugs Ther 2024; 66:81.
  3. A Ishani et al. Chlorthalidone vs. hydrochlorothiazide for hypertension-cardiovascular events. N Engl J Med 2022; 387:2401. doi:10.1056/nejmoa2212270
  4. A Ishani et al. Chlorthalidone vs hydrochlorothiazide and kidney outcomes in patients with hypertension: a secondary analysis of a randomized clinical trial. JAMA Netw Open 2024; 7:e2449576. doi:10.1001/jamanetworkopen.2024.49576
  5. G Hripcsak et al. Comparison of cardiovascular and safety outcomes of chlorthalidone vs hydrochlorothiazide to treat hypertension. JAMA Intern Med 2020; 180:542. doi:10.1001/jamainternmed.2019.7454
  6. PK Whelton 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. J Am Coll Cardiol 2018; 71:2199. doi:10.1016/j.jacc.2017.11.005
  7. D Sica et al. Blood pressure-lowering efficacy of the fixed-dose combination of azilsartan medoxomil and chlorthalidone: a factorial study. J Clin Hypertens (Greenwich) 2012; 14:284. doi:10.1111/j.1751-7176.2012.00616.x
  8. Approximate WAC. WAC = wholesaler acquisition cost or manufacturer's published price to wholesalers; WAC represents a published catalogue or list price and may not represent an actual transactional price. Source: AnalySource® Monthly. June 5, 2025. Reprinted with permission by First Databank, Inc. All rights reserved. ©2025. www.fdbhealth.com/policies/drug-pricing-policy.
© The Medical Letter, Inc. All Rights Reserved.
The Medical Letter, Inc. does not warrant that all the material in this publication is accurate and complete in every respect. The Medical Letter, Inc. and its editors shall not be held responsible for any damage resulting from any error, inaccuracy, or omission.
This article has been freely provided.
arrow to previous article
arrow to next article