3.19 Antituberculars

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]

Indications: Antitubercular medications are selective for mycobacteria work by inhibiting growth or selectively destroying mycobacteria.^[2]

Mechanism of Action: They work 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.

Special Administration Considerations:  Antitubicular 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]

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 healthcare 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 3.19.^[5],[6]

Table 3.19 Isoniazid Medication Grid

Critical Thinking Activity 3.19a

Using the above grid information, consider the following clinical scenario question:

A patient has been prescribed isoniazid as part of a multi-drug 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.