Combining losartan with amlodipine or hydrochlorothiazide – which is more effective in managing central blood pressure?

This study investigated the effect of losartan (Cozaar) in combination with amlodipine (Norvasc) or hydrochlorothiazide (Aquazide) in lowering blood pressure. They found that both combinations were similarly effective in lowering central blood pressure (cBP). 

High blood pressure (BP) or hypertension is a common condition. Managing BP levels is crucial to prevent organ damage and major events like heart attacks. There are many different types of anti-hypertensive (AHT) drugs. BP is usually measured in the arm. This represents peripheral BP (pBP). pBP can be easily monitored to determine if the AHT regimen is managing your BP. Most patients will have their medication adjusted based on pBP readings.

Some research suggests that measuring central BP (cBP) is more important. cBP is the pressure in the aorta. This vessel is directly connected to the heart. The effect of AHTs on cBP may be different to the effect on pBP. cBP may be a better indicator of organ damage. Losartan is an angiotensin receptor blocker (ARB). It is often used in combination with amlodipine. AML is a calcium channel blocker (CCB). Losartan is also commonly prescribed with hydrochlorothiazide. Hydrochlorothiazide is a diuretic. It is unclear which combination is more effective in lowering cBP.

This study included 187 patients. Patients were randomly assigned to either losartan and amlodipine (LA) or losartan and hydrochlorothiazide (LH). The dose was increased after 4 weeks if pBP was above 140 mmHg systolic (the first reading of BP). cBP was measured using an automated device. pBP and cBP were measured after 20 weeks of combined treatment. Other measurements were also taken to assess for any complications of hypertension.

At 20 weeks, there was no difference in the pBP reductions with either LA or LH. cBP was not significantly different between the groups. Pulse pressure (PP) was significantly reduced in LA-treated patients compared to LH. PP is the numeric difference between the two readings of BP. A larger than 60 PP can predict heart disease or a risk of a heart attack.

The authors concluded that both LA and LH combination lowered cBP.

70.6% patients were male. The findings in women alone may be different. Patients in this study were young with low risk for organ damage. The importance of cBP in more severe hypertension is unclear. 

If you have any concerns regarding hypertension please consult with your doctor.