The following is a summary of “Initial treatment with a single capsule containing half-dose quadruple therapy vs. standard-dose dual therapy in hypertensive patients (QUADUAL): Study protocol for a randomized, blinded, crossover trial,” published in the October 2023  issue of Heart Journal by Zhao, et al.

Combined antihypertensive medication is superior to hypertension treatment with a single agent. Guidelines for hypertension treatment unanimously support the use of dual combination therapy as an effective first antihypertensive treatment. Recent research has shown that a quadruple combination of antihypertensive medications that are administered in extremely low doses is preferable to using a single medication to treat hypertension. On the other hand, it is still being determined if low-dose quadruple therapy is superior to dual combination treatment. To assess and compare the effectiveness and safety of half-dose quadruple therapy vs. standard-dose dual therapy in the first treatment of hypertensive patients with systolic/diastolic blood pressure in the range of 140-179/90-109 mm Hg. 

The purpose of this study is to determine whether or not half-dose quadruple therapy is superior to standard-dose dual therapy. A randomized, double-blind crossover clinical trial will be conducted to compare the efficacy and safety of low-dose quadruple antihypertensives (irbesartan 75 mg + metoprolol 23.75 mg + amlodipine 2.5 mg + indapamide 1.25 mg) with standard-dose dual antihypertensives (irbesartan 150 mg + amlodipine 5 mg) in the initial treatment of patients with mild to moderate hypertension (140-179/90-109 mm Hg). 

The study requires ninety patients, who will then be recruited and randomly allocated in a ratio of 1:1 to each of the two crossover groups. Two groups will each be given a different combination treatment for four weeks, after which they will switch to the other combination therapy for a period of four weeks, followed by a wash-out period of two weeks. The patients will be monitored for four weeks to compare the antihypertensive effectiveness of the two different antihypertensive combination medications, as well as any associated side effects.

Source: sciencedirect.com/science/article/abs/pii/S0002870323001424