Side Effect: Increased Risk of Tuberculosis

What is Increased Risk of Tuberculosis?

Tuberculosis (TB) is a contagious bacterial infection by a certain bug, mycobacterium tuberculosis. TB primarily affects the lungs, but it can also affect other organs including the brain, kidneys, and bones. TB can be given to another person through the air when an infected person sneezes or coughs. This releases droplets that contain the bacteria. TB is a global health problem, affecting patients all around the world.

What does Increased Risk of Tuberculosis look like?

Patients can experience symptoms including:

• Persistent cough
• Chest pain
• Fever
• Night sweats
• weight loss
• Tiredness or fatigue

In some cases, there may be no symptoms present, especially patients that have latent TB where the bacteria are present, but inactive (not causing any acute symptoms). The appearance can depend on where TB is located. In pulmonary or lung TB, the most common form, the lungs may show up abnormal on a chest X-ray. This could mean showing nodules or cavities. A patient’s sputum may contain blood or pus when coughing as well. In extrapulmonary TB, or non-lung TB, the appearance can also vary depending on location. For example, if TB is in the spine, a patient may have spine deformity and fall down/collapse.

Who gets Increased Risk of Tuberculosis?

There are certain populations that are at increased risk of TB infection, including patients with cancer. This is because of weakened immune systems from therapy or their disease. Chemotherapy decreases the immune system’s ability to fight infection, and therefore puts patients at an increased risk of getting a TB infection. Additionally, TB in patients with cancer can be associated with the use of immunotherapy (immune checkpoint inhibitors, or ICIs) or tumor necrosis factor-alpha inhibitors (TNF-alpha inhibitors) as well. Other factors that can weaken the immune system should be monitored as well. Some are listed below:

• Smoking
• Drug abuse
• Alcohol
• Living in crowded or poorly ventilated environments.
• HIV
• Malnutrition
• Diabetes

How to prevent Increased Risk of Tuberculosis

Preventing TB in patients with cancer includes screening for TB infection before starting cancer treatment. There are certain labs that are run and must result before patients can begin therapy. Another prevention tactic is treating latent (non-symptomatic) TB infection in those who’s lab work tests return positive. One medication offered to treat latent TB is called isoniazid (Hydra®), which is an oral medication taken for a few months. This helps reduce the risk of developing active TB.

How to treat Increased Risk of Tuberculosis

TB treatment usually involves a combination of antibiotics taken over a period of several months. The exact medications will depend on the type and severity of the TB infection, and the patient’s overall health. Some options are listed below for convenience:

• Isoniazid (Hydra®)
• Rifampin (Rifadin®)
• Pyrazinamide (Tebrazid®, Rifater®)
• Ethambutol (Myambutol®)
• Other options depending on resistance: levofloxacin (Levaquin®), moxifloxacin (Avelox®), streptomycin, amikacin

Example Regimen:

• Intensive phase (months 1 – 4) = isoniazid, rifampin, pyrazinamide, and ethambutol
• Continuation phase (months 5 – 6) = isoniazid and rifampin

Of note, TB treatment in patients with cancer requires careful monitoring due to potential drug interactions with cancer treatment. It is important to discuss any new medications or treatments with a provider, to ensure all medications are optimized while minimizing the risk for adverse reactions, drug resistance, and treatment failure.