Multidrug-resistant tuberculosis (MDR-TB) is a critical health care problem calling out for effective treatment plans to prevent the increasing incidence of this disease. MDR-TB is a type of tuberculosis that is resistant to 2 or more of the drugs used in the treatment of the disease, such as isoniazid (INH) or rifampin.
Clinicians report that the 2 primary risk factors for MDR-TB are lack of patient compliance with the entire prescribed antibiotic regimen or failure of the physician to prescribe the appropriate therapy to treat TB (Table 1). Improper treatment enables single TB bacilli, which usually have a tendency toward a natural resistance to drug therapy, to multiply, thus increasing the likelihood of resistance. According to the World Health Organization (WHO), approximately 400,000 new cases of MDR-TB appear yearly in more than 100 countries. The disease is more prevalent in these countries due to insufficient drug supplies and a shortage of trained health care professionals. More than half of the patients with MDR-TB in the United States were born in other countries.
Treatment of MDR-TB
Because MDR-TB is usually resistant to the agents generally prescribed to treat TB, the first lines of defense in effectively treating MDR-TB are the antibiotics capreo-mycin (Capastat) and cy-closerine (Seromycin). Cap-reomycin is a polypeptide antibiotic that is used in combination with other TB agents when a case of MDR-TB is diagnosed. This agent is generally not recommended for use in HIV patients diagnosed with TB. Cycloserine belongs to the class of agents called antimy-cobacterials. Successful therapy for the treatment of MDR-TB sometimes requires a daily dose of capreomycin and twice-a-day dosing of cycloserine over a time period of 18 to 24 months. Table 2 lists specific characteristics for each agent.
In order for treatments to be effective, they must be individualized based on the patient?s medical history. Clinicians believe that the spread of MDR-TB can be effectively controlled if WHO?s Directly Observed Treatment, Short Course (DOTS) program is used universally. DOTS aids in preventing MDR-TB by guaranteeing that patients comply and complete the entire course of first-line antibiotic treatment. DOTS is successful due to the direct involvement of trained workers who observe patients taking their medications. DOTS-Plus is another program that aids in an attempt to cure cases of MDR-TB by using the second-line agents, capreo-mycin and cylcoserine.
The Role of the Pharmacist and Clinician
It is essential that pharmacists counsel all patients receiving any type of TB medications for the treatment to be successful. Most important, they must stress the importance of completing the antibiotic therapy even if they feel better. Without the proper interventions of health care professionals, MDR-TB could become a worldwide crisis.