The antihypertensive efficacy of a quadruple single-pill combination in patients with resistant hypertension: study protocol for a randomized, open-label, crossover trial

Trials. 2025 Jan 20;26(1):22. doi: 10.1186/s13063-025-08719-8.

Abstract

Background: Resistant hypertension (RH) is defined as uncontrolled blood pressure (BP) despite treatment with at least three or more antihypertensive agents. Compelling evidence has shown that such a population has a greater risk of cardiovascular events as well as mortality. Although mineralocorticoid receptor antagonists (MRAs) have been shown to be an effective fourth-line treatment for RH, a significant proportion of RH patients do not achieve their blood pressure target. Compound reserpine and triamterene tablets, a traditional Chinese quadruple single-pill combination, have been proven to have good antihypertensive effects as well as safety, and are promising effective antihypertensive drugs for treating RH.

Methods: A randomized crossover clinical trial will be conducted to compare the efficacy and safety of compound reserpine and triamterene tablets treatment regimen (two tablets of olmesartan/amlodipine (OA) + one tablet of compound reserpine and triamterene tablets) with those of a standard treatment regimen (two tablets of OA + indapamide 2.5 mg + spironolactone 20 mg) in patients with RH. Forty patients will be recruited and randomly assigned in a 1:1 ratio to 2 crossover groups. The two groups will receive different combination therapies for 6 weeks and will then switch to the other combination therapy for 6 weeks, with a 4-week wash-out. The primary outcome will be the reduction in average 24-h systolic blood pressure after 6 weeks of intervention between the two groups.

Discussion: This study aimed to evaluate whether the compound reserpine and triamterene tablets treatment regimen (A + C + 0) results in a greater reduction in blood pressure in RH patients than the standard treatment regimen (A + C + D + spironolactone).

Trial registration: Chinese Clinical Trial Registry ChiCTR2400081878. Registered on March 14, 2024 ( http://www.chictr.org.cn ).

Keywords: Compound reserpine and triamterene tablets; Randomized crossover trial; Resistant hypertension; Spironolactone.

Publication types

  • Clinical Trial Protocol

MeSH terms

  • Adult
  • Aged
  • Amlodipine / administration & dosage
  • Amlodipine / adverse effects
  • Amlodipine / therapeutic use
  • Antihypertensive Agents* / administration & dosage
  • Antihypertensive Agents* / adverse effects
  • Antihypertensive Agents* / therapeutic use
  • Blood Pressure* / drug effects
  • China
  • Cross-Over Studies*
  • Drug Combinations*
  • Drug Resistance
  • Drug Therapy, Combination
  • Female
  • Humans
  • Hypertension* / drug therapy
  • Hypertension* / physiopathology
  • Imidazoles
  • Male
  • Middle Aged
  • Randomized Controlled Trials as Topic*
  • Reserpine / administration & dosage
  • Reserpine / adverse effects
  • Tetrazoles
  • Treatment Outcome
  • Triamterene / administration & dosage
  • Triamterene / adverse effects
  • Young Adult

Substances

  • Antihypertensive Agents
  • Drug Combinations
  • Reserpine
  • Triamterene
  • Amlodipine
  • olmesartan
  • Imidazoles
  • Tetrazoles