Refractory hypertension is high blood pressure that cannot be managed even after the use of 5 or more antihypertensive medications.

Refectory hypertension is high blood pressure that can’t be managed despite using five or more medications.

This is different from other types of hypertension, where you may use several medications or none at all. Hypertension is classed as refractory only when factors that can influence blood pressure — smoking, diet, incorrect medication dosage, white-coat effect, and alcohol usage — are ruled out as causes.

This article explains more about refractory hypertension, how it varies from other hypertension, what treatment may look like, and what you may need to discuss with your healthcare team.

Refractory hypertension is high blood pressure that cannot be managed even using five or more blood pressure medications.

To be considered refractory hypertension, the five medications tried need to be in different medication classes and have included a long-acting thiazide diuretic, such as chlorthalidone, and a mineralocorticoid receptor antagonist (MRA), such as spironolactone.

These medications also need to have been taken at their maximum doses or at the maximum amounts you can tolerate.

It’s also important that any factors interfering with treatment or blood pressure measurement are ruled out. These factors can make it appear as if you have refractory hypertension when you do not.

Factors that can cause pseudo-refractory hypertension include:

  • The white-coat effect: Many people have higher blood pressure readings at the doctor’s office than at home. This is called the white-coat effect or white coat syndrome. It’s linked to the stress and anxiety that being at a medical appointment can produce.
  • Wrong medication dose: Hypertension isn’t classed as refractory if adjusting the dosage of a medication helps to manage it.
  • Wrong medication: Refectory hypertension is resistant to classes of medications, not specific medications. If going from one medication to another within a medication class helps manage hypertension, it is not refractory.
  • Other medications: Some medications can raise blood pressure or interfere with how blood pressure medications work.
  • Supplements: This may include prescription medications or other types of supplements. They can interfere with blood pressure medications and spike blood pressure.
  • Skipping medications: Not taking your blood pressure medications can make it appear as if those medications aren’t working correctly. This can look like refractory hypertension, but true refractory hypertension means that blood pressure can’t be managed even when medications are taken correctly and at the highest tolerable doses.
  • Smoking: Smoking increases blood pressure because it narrows the arteries. Smokers aren’t considered to have refractory hypertension unless they quit and no changes to blood pressure occur.
  • Consuming excess sodium: High levels of sodium in your diet increase your blood pressure. Eliminating them can lower your pressure. Someone needs to be on a low sodium diet without changes to blood pressure before hypertension can be called refractory.
  • Lack of physical exercise: Exercise decreases blood pressure. Someone who isn’t getting some physical activity in their week isn’t considered to have refractory hypertension.
  • Consuming too much alcohol: Frequently consuming large amounts of alcohol raises blood pressure.
  • Inadequate measurement: Sometimes, blood pressure is simply measured incorrectly due to factors such as the device, the placement of the cuff on the arm, or your arm’s position during measurement. Ensuring that accurate measurements are being taken is important in diagnosing refractory hypertension.
  • Arterial stiffening: The arteries in your arm can stiffen and prevent blood pressure cuffs from gathering an accurate reading.

You may hear other terms referring to different types of hypertension. These can include:

Resistant hypertension:This type of hypertension cannot be managed despite treatment with three or more medications. This means someone could be diagnosed with resistant hypertension before trials with additional medications change their diagnosis to refractory hypertension. You can read more here.

Uncontrolled hypertension: This type means an individual has blood pressure above 140/90 mmHg. It can refer to when high blood pressure has been untreated or when treatments have been ineffective.

Hypertension doesn’t always cause symptoms. Many people have hypertension without ever knowing it. Of course, refractory hypertension is defined by its response to treatment, so people with this condition will likely know that they have high blood pressure. However, that doesn’t mean they’ll have noticeable symptoms.

When refractory blood pressure does cause symptoms, they can include:

Often, there’s no identifiable cause for refractory hypertension. When there is a cause, that cause typically needs to be treated first before the hypertension can be addressed. Some potential underlying causes of refractory hypertension include:

Treatment options depend on underlying conditions, co-occurring conditions, and overall health. Many treatments for refractory hypertension are still in the clinical trial phase.

This is because refractory hypertension is, by definition, resistant to common and available hypertension medications. Newer treatments are being developed and might be readily available in the future. Your doctor might be able to suggest trials that are a good fit for you and your specific medical profile. Possible options include:

  • Alternate medications: One of the first treatment options for refractory hypertension is the use of medications that aren’t typically used to treat blood pressure, but that can help some people successfully manage hypertension. Factors such as your overall heart health will influence which of these medications your doctor orders.
  • Baroreflex Activation Therapy (BAT): BAT is a device that uses electrical impulses to help control nerve activity and slow down heart rate. It’s currently being trialed as a way to help reduce blood pressure for people with refractory hypertension.
  • Continuous Positive Airway Pressure (CPAP): A CPAP device is commonly used for people with obstructive sleep apnea (OSA). It’s being trialed as a way to help manage blood pressure for people with refractory hypertension.
  • Renal denervation: Renal denervation decreases the activity of kidney nerves and is thought to reduce overall central nerve activity. Trials are underway to see if this treatment could help lower blood pressure in people with refractory hypertension.

Refectory hypertension is high blood pressure that can’t be managed even after five medications have been tried. To be considered refractory hypertension, factors that can influence blood pressure, such as diet, smoking status, medication dosage, and white-coat effect, also need to be ruled out.

There’s often not a known cause for refractory hypertension, but possible causes include conditions that affect the adrenal and thyroid glands and kidney health conditions.

Treatment depends on any co-occurring health conditions or underlying causes. Many treatments for refractory hypertension are still in clinical trials. Options start with alternate medications to help manage blood pressure. Trials are studying new options such as BAT and CPAP devices.