Half of treatment-resistant hypertension cases may be due to suboptimal therapy.

This study investigated possible reasons why some patients with high blood pressure appear to have treatment-resistant hypertension and have uncontrolled blood pressure levels. 

Hypertension (high blood pressure) is when pressure in blood vessels is too high. This can cause a number a health problems such as a heart attack, heart failure or stroke.

Antihypertensive drugs are used to treat hypertension. However, some patients have treatment-resistant hypertension which is when they have received more than 3 different types of antihypertensive drugs but none have successfully reduced their blood pressure.

However, it is not known whether these patients have been receiving the right or ‘optimal’ drug dose which may account for their ‘apparent’ treatment-resistant hypertension. 

This study investigated whether patients with apparent treatment-resistant hypertension were receiving the right drug dose for hypertension. The study included 468,877 hypertensive patients.

The study found that 32% of the patients had uncontrolled hypertension. Of these patients, 30% were considered to have treatment-resistant hypertension as they had taken >3 different types of blood pressure drugs.

Of these patients, only 15% were prescribed optimal therapy. Optimal therapy for patients with treatment-resistant hypertension was defined as taking a diuretic (a type of antihypertensive drug e.g. Chlorothiazide (Diuril) and two or more other blood pressure drugs (such as beta blockers, angiotensin-converting enzyme (ACE) inhibitors, or calcium channel blockers), with each drug being prescribed at a dose that is >50% of the maximum recommended or approved dose for hypertension. 

The study concluded that prescribing more optimal drug therapy for uncontrolled hypertensives could improve hypertension control.  

Many other factors can contribute to apparent treatment-resistant hypertension, such as patients not complying with taking their correct dose due to side effects, expensive cost of the drug, or forgetting to take them. Also doctors should rule out ‘white-coat hypertension’, which is when a person’s blood pressure may be higher when it is measured at a clinic than it is for the rest of the day – measuring blood pressure regularly throughout the day at home can rule this out.  

If you or someone you know are receiving antihypertensive drugs and have apparent treatment-resistant hypertension, talk to a doctor about increasing the dose, regular home blood pressure monitoring, or whether you are struggling to take the drugs on a regular basis.