M. tuberculosis is the causative agent of tuberculosis (TB), a disease that primarily impacts the lungs but can infect other parts of the body as well. It has been estimated that one third of the world’s population has been infected with M. tuberculosis, and millions of new infections occur each year. Treatment of M. tuberculosis is challenging and requires patients to take a combination of drugs for an extended time. Complicating treatment even further is the development and spread of multidrug-resistant strains of this pathogen.[1]
Mechanism of Action: They work by impacting the synthesis or transcription of mycobacteria RNA or inhibiting the synthesis of mycolic acids in the cellular wall. Mycobacteria can develop resistance to antitubercular medications; therefore, strict compliance to drug regimen must be emphasized.
Indications: Antitubercular medications are selective for mycobacteria work by inhibiting growth or selectively destroying mycobacteria.[2]
Nursing Considerations: Antitubercular medications require at least six months of treatment. Many antitubercular medications may impact liver function, and liver enzymes should be monitored carefully. Other side effects to medication administration include GI symptoms, peripheral neuropathy, and vision changes.[3]
Side Effects/Adverse Effects: Common side effects of antitubercular medications include GI upset. Adverse effects include hepatotoxicity. Antitubercular medications can also decrease the effectiveness of oral contraceptives, so backup methods should be used.
Patient Teaching & Education: Advise patients that medications must be taken as directed. It is important that patients understand the significance of continuing drug therapy even after symptoms have resolved to prevent the spread of disease. Drug therapy may be continued for six months to two years. If a patient notices any change in visual acuity or eye discomfort, it should be reported immediately to the health care provider. Patients should also be advised to avoid alcohol during antitubercular therapy because of the increased risk of liver toxicity. Foods containing tyramine such as tuna and Swiss cheese should be avoided.[4]
Now let’s take a closer look at the medication grid on isoniazid in Table 3.19a and rifampin in Table 3.19b.[5]
Table 3.19a Isoniazid Medication Grid
| Class/Subclass | Prototype/Generic | Administration Considerations | Therapeutic Effects | Side/Adverse Effects |
|---|---|---|---|---|
| Antitubercular (also known as antimycobacterials) | isoniazid | Direct observed therapy (DOT) may be initiated to ensure compliance with long-term therapeutic regimen
Multiple-drug resistant tuberculosis (i.e., resistance to at least isoniazid and rifampin) presents difficult treatment problems. Treatment must be individualized and based on susceptibility studies May decrease effectiveness of oral contraceptives. Patients should be counseled to use alternate form of oral contraception Vitamin B6 supplementation is necessary in some patients for prevention of peripheral neuropathy |
Negative sputum smears
Prevention or elimination of TB symptoms: Productive cough, fever, and night sweats |
GI upset
Hepatotoxicity May decrease effectiveness of oral contraceptives |
Table 3.19b Rifampin Medication Grid
| Class/Subclass | Prototype/Generic | Administration Considerations | Therapeutic Effects | Side/Adverse Effects |
|---|---|---|---|---|
| Antitubercular (also known as antimycobacterials) | rifampin | Direct observed therapy (DOT) may be initiated to ensure compliance with long-term therapeutic regimen
Multiple-drug resistant tuberculosis (i.e., resistance to at least isoniazid and rifampin) presents difficult treatment problems. Treatment must be individualized and based on susceptibility studies May decrease effectiveness of oral contraceptives. Patients should be counseled to use alternate form of oral contraception Vitamin B6 supplementation is necessary in some patients for prevention of peripheral neuropathy |
Negative sputum smears
Prevention or elimination of TB symptoms: Productive cough, fever, and night sweats Rifampin can also be used to treat meningitis, staph infections, chronic bacterial infections (such as leprosy), and as prophylaxis for meningococcal disease. |
GI upset
Hepatotoxicity May decrease effectiveness of oral contraceptives |
Critical Thinking Activity 3.19
Using the above grid information, consider the following clinical scenario question:
A patient has been prescribed isoniazid as part of a multidrug regimen for resistant TB. Direct observed therapy (DOT) has been initiated. The patient asks the nurse, “What does direct observed therapy mean?” What is the nurse’s best response?
Note: Answers to the Critical Thinking activities can be found in the “Answer Key” sections at the end of the book.
- This work is a derivative of Microbiology by OpenStax licensed under CC BY 4.0. Access for free at https://openstax.org/books/microbiology/pages/1-introduction ↵
- This work is a derivative of Microbiology by OpenStax licensed under CC BY 4.0. Access for free at https://openstax.org/books/microbiology/pages/1-introduction ↵
- This work is a derivative of Microbiology by OpenStax licensed under CC BY 4.0. Access for free at https://openstax.org/books/microbiology/pages/1-introduction ↵
- uCentral from Unbound Medicine. https://www.unboundmedicine.com/ucentral ↵
- This work is a derivative of DailyMed by U.S. National Library of Medicine in the Public Domain. ↵
