Side effects of Latent Tuberculosis Infection treatment

The decision to screened and treat LTBI is based on age and risk factors (Pai & Menzies, 2009). Age is a component of the decision because risk of liver toxicity from LTBI medication increases with age. For example, increasing Isoniazid (INH) induced liver toxicity is found in those over the age of 35 and greatly in those over the age of 50. Furthermore, some researches have found the cumulative risk of LTBI reactivation and medication benefits decreases with age. The following is a current suggested guideline for LTBI testing and treatment according to patient’s age and risk factors,

LTBI treatment is composed of 3 main drugs: Isoniazid (INH), Rifampin, and Pyrazinamide. Some providers may choose to combine two of types of drugs to meet patient’s specific needs such as adherence, baseline liver enzyme level, and existence of other illness/diseases (Horsburgh, 2009). The below table lists the recommended LTBI medications in order of preference, side effects, drug interactions, contraindications, and monitoring (click on image),

In certain situations a patient might be taken off a certain medication therapy and put on a different therapy due to adverse side effects. The following are examples of such situations.
Isoniazid (INH): Isoniazid should be stop immediately if s/sx of liver toxicity occurs (Lehne, 2007). Health care provider must be notified immediately and liver function panel tests requested. Furthermore, INH may not be resumed if the serum liver enzyme aspartate aminotransferase (AST) is 3 to 5 times above upper limit of normal (Lehne, 2007).
Pyrazinamide: Pyrazinamide should be stopped if significant liver injury occurs. Furthermore, Rifampin and Pyrazinamide used for short-term therapy has been found to cause high incidences of hospitalizations and deaths from liver injury (Lehne, 2007). Hence Rifampin and Pyrazinamide co-usage should never be used in patient with acute liver disease or a history of Isoniazid-induced liver injury.

The more I delve into Tuberculosis, the more I feel as if I am in a quagmire. Tuberculosis disease screening protocols and diagnostics is different from that of latent Tuberculosis infection (LTBI). One of my cohorts told me, "When you are talking about TB, you have to specified which one you are talking about. Are you talking about TB disease, LTBI, or TB infection?" He is darn right. Not only do I have to specified which one I am talking about, I have to differentiate among the existing 3 or 4 classes of TB. A work in TB business is definitely cut out for me. Please, tell me that the end of the tunnel is near!

References

Horsburgh, C.R., (2009). Treatment of latent tuberculosis infection in HIV-seronegative adults. In B. Rose (Ed.),UpToDate. Available from http://www.uptodateonline.com/

Lehne, R. A. (2007). Antimycobacterial Agents: Drugs for Tuberculosis, Leprosy, and Mycobacterium avium Complex Infection. In K. Geen & L. Borstell (Eds.), Pharmacology for nursing care (pp. 1014-1028). St. Louis, Mo: Saunders Elsevier.

Pai, M., & Menzies, R., (2009). Diagnosis of latent tuberculosis infection in adults. In B. Rose (Ed.),UpToDate. Available from http://www.uptodateonline.com

Recommended Tuberculosis treatment guidelines

The Center for Disease Control and Prevention, the American Thoracic Society, and the Infectious Diseases Society of America (Centers for Disease Control and Prevention [CDC], 2003) recommends a 2-month chemotherapy of isoniazid, rifampin, pyrazinamide, and ethambutol for the treatment of Tuberculosis followed by a 4-month continuation phase of isoniazid and rifampin. The CDC also added that those who are on antivirals for HIV infection seek care from a healthcare provider who is experienced in treating patients with HIV/TB co-infections due to the two diseases' numerous drug interactions and disease dynamics. Below are flow diagrams of the guideline recommendations (click on images),


Similarly Washington State Department of Health (Washington State Department of Health [DOH], 2009) recommend 2 months phase of isoniazid, rifampin, pyrazinamide, and ethambutol followed by a 4-month continuation phase of isoniazid and rifampin. Below is a flow diagram I made that represents DOH's TB treatment recommendation (click on image),

While on TB treatment therapy, the side effects that are most important to monitor are liver function, hypersensitivity, malaise, headache, fatigue, loss of appetite, dizziness, numbness, tingling, decline in visual acuity (with Ethambutol), blood disorders such as blood in urine and increase bruising (with Rifampin), and of course drug interactions!

As you could see from the flow diagrams, managing TB can be quite complicated due to the complexity of the disease. As a nursing student whose focus area is in infectious disease and who is interested in refugee/immigrant health, I feel a sense of pressure to understand and memorize these guidelines in order to provide quality nursing care to my future TB patients.

Centers for Disease Control and Prevention. (2003). MMWR weekly report: Treatment of Tuberculosis. American Thoracic Society, CDC, and Infectious Diseases Society of America. Retrieved November 2, 2009 from http://www.cdc.gov/mmwr/PDF/rr/rr5211.pdf

Washington State Department of Health. (2009). Washington State: Tuberculosis Service Manual (DOH Publication No. 373-071). Retrieved from
http://www.doh.wa.gov/cfh/TB/Manual/Sections/CompleteManual.pdf

Major signs and symptoms of TB disease

Primary Tuberculosis infection usually does not have symptoms. However, if symptoms due occur they may include cough (sometimes producing phlegm), coughing up blood, excessive sweating especially at night, fatigue, fever, and unintentional weight loss. Also breathing difficulty, chest pain, and wheezing may occur.
In a prospective cohort study of “new TB converters” living in Faroe Islands off the coast of Norway from 1932 to 1946, the following s/sx and their respective frequencies were found,

• Low grade fever, 70%
  a. Could be as high as 39ºC
  b. Lasted for an average of 2 to 3 weeks
  c. Resolved by 10 weeks in 98% of patients
• Chest pain and painful respiration, 25%
  a. One-half of those with painful respiration
• Pain worsen upon swallowing , Some
• Fatigue, Rare
• Cough, Rare
• Arthralgias, Rare
• Pharyngitis, Rare
  

With primary TB disease, the most common chest X-ray findings in the order of frequencies are, 1) hilar adenopathy, 2) pleural effusion, and 3) pulmonary infiltrates. It is worthwhile to note here that cases with pulmonary infiltrates, 43% have pleural effusion and 33% have lower lobes infiltrates.

References

http://www.cdc.gov/tb/topic/basics/default.htm#difference

Medline Plus: http://www.nlm.nih.gov/medlineplus/ency/article/000077.htm