Can Tuberculosis Cause High Blood Pressure?

Tuberculosis (TB) is a well-known infectious disease primarily affecting the lungs, but its potential impact on other bodily systems, including cardiovascular health, has raised questions among patients and healthcare professionals alike. Many patients report experiencing high blood pressure only after being diagnosed with TB, even if they had no prior history of hypertension. Some note that their blood pressure rises shortly after taking anti-TB medications, while others—already managing hypertension with medication—find their blood pressure becomes erratic and difficult to control after developing TB. So, what is the connection between these two conditions? And why does blood pressure seem to spiral out of control when TB is involved?

Can TB Cause Hypertension?

Scientific research indicates that most forms of TB—such as pulmonary TB or bone TB—do not directly cause high blood pressure. However, when TB affects the kidneys, known as renal tuberculosis, a link with hypertension may exist. This connection can be better understood through two related terms: hypertensive kidney disease and renal hypertension.

Hypertensive kidney disease refers to kidney damage caused by long-standing high blood pressure, eventually leading to chronic kidney disease or failure. Conversely, renal hypertension is a type of secondary hypertension caused by kidney disease, and renal TB can be one of the underlying causes.

In some cases, renal TB may resolve on its own without noticeable symptoms, referred to as pathological renal TB. However, if the infection progresses, it may lead to significant hypertension. It's also possible for TB and hypertension to coexist independently without any direct relationship. Therefore, both conditions should be treated separately and effectively.

Some recent studies suggest that TB infection might contribute to the development of hypertension, though this theory has not yet been widely accepted or conclusively proven.

Can Anti-TB Medications Raise Blood Pressure?

Common first-line anti-TB drugs include isoniazid, rifampin, ethambutol, pyrazinamide, and streptomycin. Generally, these medications are not known to directly elevate blood pressure. However, some reports indicate that rifampin and related drugs (like rifamycin and rifapentine) may cause temporary increases in blood pressure in individuals without a prior history of hypertension. Once these medications are discontinued, blood pressure often returns to normal, possibly due to increased sympathetic nervous system activity.

For patients already on antihypertensive therapy, anti-TB drugs—especially rifampin—can accelerate the metabolism of blood pressure medications in the liver. This can reduce the effectiveness of drugs like calcium channel blockers, particularly nifedipine, leading to poor blood pressure control and greater fluctuations.

To manage this interaction, it may be advisable to avoid nifedipine and consider alternative calcium channel blockers or switch to rifabutin, which has a weaker effect on liver enzymes. Additionally, long-term anti-TB treatment can lead to liver or kidney damage, and medications like diammonium glycyrrhizinate—used to protect liver function—can sometimes raise blood pressure. In such cases, safer alternatives like tiopronin or reduced glutathione may be more appropriate for liver support.

Common Side Effects of Anti-TB Drugs and How to Minimize Them

Isoniazid

Isoniazid is a liver enzyme inhibitor, which means it can slow the metabolism of other medications. Dose adjustments may be necessary to avoid toxicity. Common side effects include liver dysfunction, peripheral neuropathy (tingling or numbness in limbs), psychiatric symptoms, and seizure induction.

Rifampin

As a potent liver enzyme inducer, rifampin can decrease the effectiveness of other drugs, including antihypertensives and hormonal therapies. It may also cause allergic reactions such as rash or flu-like symptoms and liver damage.

Streptomycin

This drug can damage the kidneys and cranial nerves, leading to dizziness, tinnitus, hearing loss, and numbness around the mouth.

Pyrazinamide

In addition to liver toxicity, pyrazinamide can elevate uric acid levels, potentially triggering gout. It should not be used alongside diuretics like furosemide.

Ethambutol

Ethambutol can cause optic neuritis, leading to blurred vision or difficulty distinguishing colors.

Managing Side Effects and Preventing Drug Resistance

Drug-resistant TB has become a growing global health concern, making it more difficult to treat. To combat this, medical professionals emphasize the "eight-character principle" of TB treatment: early initiation, combination therapy, adequate dosage, and full course completion.

Modern treatment options include standardized chemotherapy and shorter treatment regimens, both of which must be tailored by a physician. Patients should be closely monitored for any signs of drug-related side effects, and protective measures for liver and kidney function should be prioritized throughout treatment.