Side Effect: High Blood Pressure

What is high blood pressure, or hypertension?

High blood pressure, also known as hypertension, is a condition where the force of blood against the walls of blood vessels is consistently too high. Normal blood pressure is defined as having a systolic blood pressure (the top number) of 120 mmHg (pronounced “millimeters of mercury”) or lower and a diastolic blood pressure (the bottom number) of 80 mmHg or lower. Hypertension is diagnosed when a person’s systolic blood pressure throughout the day is on average 130 mmHg or higher, or if diastolic blood pressure throughout the day is on average 80 mmHg or higher.

When checking blood pressure at home, it is important to check it at the same time each day to determine a consistent, accurate measurement. Many patients check their blood pressure using a home blood pressure machine first thing in the morning when they wake up. They then record these values and report them to their clinic to determine if a change in blood pressure medication is needed.

Importantly, having one or a few blood pressure measurements above the normal limits does not necessarily mean you have high blood pressure problems, especially if there is a known cause such as pain, or “white coat syndrome” which is a high blood pressure reading in the doctor’s office. If you do not know, and are concerned, ask your doctor if you have high blood pressure.

What does high blood pressure, or hypertension look like?

High blood pressure often has no obvious symptoms, even at very high levels. However, some people with hypertension may experience symptoms such as headaches, shortness of breath, chest pain, and rarely nosebleeds. If left untreated, hypertension may lead to significant complications such as heart failure, atrial fibrillation, a stroke, heart attack, or chronic kidney disease.

Who gets high blood pressure, or hypertension?

Risk factors for high blood pressure include age, obesity, physical inactivity, smoking, drinking alcohol, high salt diet, stress, chronic pain, or having a family history of high blood pressure. Some medical conditions that may increase risk include kidney disease, diabetes, and sleep apnea. Certain cancer therapies may also increase the risk of developing high blood pressure. The most common class of medications to cause high blood pressure are vascular endothelial growth factor (VEGF) inhibitors such as bevacizumab, various classes of oral tyrosine kinase inhibitors (TKI’s), anti-estrogen/testosterone agents, and supportive care medications such as corticosteroids (prednisone or dexamethasone) and tacrolimus (also known as Prograf®).

How do you prevent high blood pressure, or hypertension in patients with cancer?

Lifestyle changes, such as maintaining a healthy weight, exercising regularly, limiting alcohol consumption, quitting smoking, managing stress, and reducing salt intake can help prevent or treat high blood pressure when it is already present.

How is high blood pressure, or hypertension in patients with cancer treated?

The treatment of high blood pressure in cancer patients can be complex. Treatment should be tailored to the individual patient and may include lifestyle modifications (as discussed above), antihypertensive medications (also known simply as “blood pressure medications”), and treatment of any underlying medical conditions that may be contributing to increased blood pressure. Some common antihypertensive drug classes, and corresponding medications include:

• Angiotensin-converting enzyme inhibitors (ACEI) – lisinopril (Prinivil®, Zestril®), enalapril (Vasotec®), ramipril (Altace®)
• Angiotensin II receptor blockers (ARB) – losartan (Cozaar®), valsartan (Diovan®), irbesartan (Avapro®)
• Calcium channel blockers (CCB) – amlodipine (Norvasc®), nifedipine (Procardia®), diltiazem (Cardizem®), verapamil (Calan®)
• Thiazide diuretics – hydrochlorothiazide (HCTZ), metolazone (Zaroxolin®), chlorthalidone (Thalitone®)
• Beta blockers – metoprolol (Troprol®, Lopressor®), atenolol (Tenormin®), carvedilol (Coreg®)

Blood pressure medication doses often require adjustment over time to achieve the desired effect. If one blood pressure medication is not enough to bring the blood pressure to the normal range despite maximally tolerated doses, additional medications from different drug classes may need to be combined as well. For example, if someone starts by taking chlorthalidone, and ACE inhibitor may also need to be added if blood pressure is not at goal within a predefined period of time by your doctor.

If high blood pressure is a direct result of cancer treatment, its important that once the treatment is stopped, that blood pressure is monitored closely after stopping cancer therapy as the dosage of antihypertension medications may need to be lowered or they may need to be stopped completely to avoid experiencing too low blood pressure (hypotension).