SAN DIEGO – Health care workers with latent tuberculosis infection (LTBI) were significantly more likely to continue a shorter course of weekly rifapentine plus isoniazid (INH) than daily INH monotherapy, researchers reported at an annual scientific meeting on infectious diseases.
“Consideration should be given to no longer routinely recommending INH for the treatment of LTBI among health care workers,” said Dr. Esther Arguello Perez of Memorial Sloan Kettering Cancer Center, New York.
©CDC/Elizabeth "Libby" White
Health care workers face a greater risk of TB infection than the general population, regardless of the income level in the country where they live; patients with undiagnosed laryngeal or pulmonary TB usually pose the greatest risk, especially during procedures that cause coughing, such as sputum induction and bronchoscopy (Int J Tuberc Lung Dis. 2007;11[6]:593-605).
Although occupational TB testing is routine in U.S. health care organizations, more than half of health care workers who start treatment for LTBI historically have failed to finish (Chest. 2010;137[2]:401-9. doi: 10.1378/chest.09-0394). The standard LTBI regimen – 300 mg INH daily for 9 months – has been linked to potentially intolerable adverse effects such as hepatotoxicity, persistent gastrointestinal symptoms, rash, and neuropsychiatric problems (Drug Healthc Patient Saf. 2014;6:145-9. doi: 10.2147/DHPS.S68837).
In a 2011 multicenter trial, investigators reported a significantly higher completion rate for weekly rifapentine plus INH (900 mg each; 82% vs. 69% for daily INH; P < .001). Rates of adverse effects were significantly lower with weekly rifapentine plus INH, although grade 3-4 events and risk of death did not differ between the groups (N Engl J Med. 2011;365:2155-66. doi: 10.1056/NEJMoa1104875). The results of that trial quickly transformed recommendations for LTBI treatment (MMWR. 2011:60(48);1650-53).
Memorial Sloan Kettering implemented weekly rifapentine plus INH for its LTBI personnel in 2011. By 2014, about three-quarters of personnel with LTBI received rifapentine plus INH, while the rest were evenly split between rifampin and INH monotherapy, Dr. Arguello Perez reported at the combined annual meetings of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, and the Pediatric Infectious Diseases Society.
To understand how health care workers’ attitudes and treatment acceptance shifted along with practice, the investigators reviewed records from all health care workers at Memorial Sloan Kettering who were diagnosed with LTBI for 2005-2014. Among 930 patients, only 357 (38%) accepted treatment, although 76% of these individuals finished the regimen they started, she noted. Rifapentine plus INH had the highest completion rate (88%), significantly exceeding rates for a 4-month course of daily rifampin (84%) and for 9 months of INH monotherapy (70%; P < .01 for both differences). In contrast, completion rates for rifampin and INH did not significantly differ, Dr. Arguello Perez said.
Notably, LTBI treatment completion rates among health care workers rose by 26% between 2013, when most prescriptions were for rifampin or INH monotherapy, and 2014, when most were for rifapentine plus INH. “Health care workers might be more likely to accept treatment for LTBI if they know about alternatives to INH,” she concluded.
Dr. Arguello Perez and her associates reported no funding sources and had no financial disclosures.