Low-Dose Combinations of Anti-Hypertensive Drugs May Reduce Side Effects

Quarter-doses of 2 hypertension drugs more effective than a standard dose of 1 drug.

Typically, providers tend to prescribe as few drugs as possible to achieve disease control, as multiple medications can significantly increase the risk of drug-drug interactions. These interactions can result in serious adverse events and even hospitalization.

Findings from a new study published by Hypertension suggest that lower-dose combinations of drugs may effectively control high blood pressure. The authors found that administering quarter-doses of a combination of blood pressure-lowering drugs was able to reduce side effects for patients compared with a standard dose of 1 drug.

This is the first study to examine the risks and benefits of quarter-dose therapy to full-dose and placebo.

“Widespread control of blood pressure is generally low, even in high-income countries. The largest global survey of hypertension patients showed 88% of those aware of hypertension are treated with medications, but only 1 in 3 were able to gain control of their blood pressure,” said study author Anthony Rodgers, MBChB, PhD. “Because high blood pressure is so common and serious, even small improvements in management can have a large impact on public health.”

While there are multiple different types of hypertension drugs, each includes side effects, such as weakness, dizziness, insomnia, headache, muscle cramps. Reducing the likelihood of these side effects could lead to improved quality of life for patients with hypertension.

Included in the meta-analysis were findings from 42 previously conducted trials, which included 20,284 patients with hypertension.

All patients included were taking various doses of medications or were not on a therapy. Patients were treated with ACE inhibitors, angiotensin receptor blockers, beta blockers, calcium channel blockers, and thiazides.

Interestingly, the authors discovered that a combination of 2 drugs administered at quarter-doses were just as effective as 1 drug at the standard dose, according to the study.

When 4 drugs at a quarter-dose were administered, the authors found that the therapy was nearly twice as effective compared with 1 drug at the standard dose.

In addition to the improvements in efficacy, the authors discovered that the 1 drug at a quarter-dose and 2 drugs at quarter-doses resulted in similar numbers of side effects, according to the study. The authors reported there was not substantial information about side effects resulting from the combination of 4 drugs.

Although these results are promising, the authors warn that there is not enough information to direct physicians to change prescribing habits, especially for patients who have achieved disease control. Additionally, the authors said that there are few low dose combinations of drugs currently available.

If further studies find this method is safe, it could reduce the occurrence of adverse events and related costs for patients with hypertension.

“This new approach to treatment needs more research before it can be recommended more widely,” Dr Rodgers said. “The findings have not yet been tested in large long-term trials. People should not reduce the doses of their current medications.”