What are the characteristics of Tuberculosis (TB) in adolescents?

From the Guidelines

Tuberculosis (TB) in adolescents requires prompt diagnosis and treatment with a standard four-drug regimen consisting of isoniazid (INH), rifampin (RIF), pyrazinamide (PZA), and ethambutol (EMB) for the first two months, followed by INH and RIF for an additional four months, totaling six months of therapy. For drug-susceptible pulmonary TB, the typical adult dosing applies to adolescents: INH 5 mg/kg daily (max 300 mg), RIF 10 mg/kg daily (max 600 mg), PZA 15-30 mg/kg daily (max 2000 mg), and EMB 15-25 mg/kg daily (max 1600 mg) 1. Directly observed therapy (DOT) is recommended to ensure adherence. Adolescents present unique challenges including potential delayed diagnosis due to atypical presentations, concerns about medication adherence, and psychosocial issues that may affect treatment success.

Some key points to consider in the treatment of TB in adolescents include:

• Screening for latent TB infection is also important in high-risk adolescents using either tuberculin skin testing or interferon-gamma release assays 1.
• Treatment for latent TB typically involves INH daily for 9 months or a shorter 3-4 month regimen of INH plus rifapentine weekly 1.
• Adolescents with TB require comprehensive care addressing both medical and psychosocial needs, with attention to potential drug interactions, especially with contraceptives in sexually active female patients.
• The use of pyridoxine is recommended for adolescents with TB, especially those who are HIV infected, malnourished, breast fed, or are being given terizidone, cycloserine, or high-dose isoniazid 1.
• Steroids have been demonstrated to improve outcome in children with TBM and are additionally advised for airway obstruction and pericardial TB 1.

It is essential to note that the treatment of TB in adolescents should be individualized, taking into account the specific needs and circumstances of each patient. The treatment regimen should be tailored to the patient's age, weight, and medical history, as well as the severity and extent of the disease. Regular monitoring and follow-up are crucial to ensure that the patient is responding to treatment and to address any potential side effects or complications.

From the Research

Treatment of TB in Adolescents

• The treatment of tuberculosis (TB) in adolescents has seen significant advances in recent years, with the development of new drugs and regimens 2.
• The World Health Organization (WHO) recommends two new regimens lasting for only 4 months for the treatment of drug-susceptible TB, as well as a shortened 6-month regimen for treatment of drug-susceptible TB meningitis 2.
• The development of child-friendly formulations for many of these drugs has further enhanced the ability to safely and effectively treat drug-susceptible and drug-resistant TB in children and adolescents 2.

Diagnosis and Testing

• The diagnosis of latent tuberculosis infection (LTBI) in children and adolescents can be challenging, with the tuberculin skin test (TST) having many limitations, including difficulty in administration and interpretation, and false-positive results 3.
• Interferon-gamma release assays (IGRAs) are blood tests that use antigens specific for M tuberculosis, and yield fewer false-positive results than the TST 3.
• Both IGRAs and the TST have reduced sensitivity in immunocompromised children, including children with severe TB disease 3.

Treatment Regimens

• First-line therapy for active tuberculosis has remained unchanged for nearly 40 years, with isoniazid, rifampin, pyrazinamide, and ethambutol for the initial two-month phase followed by isoniazid and rifampin for 4 to 7 months being the standard treatment for people at low risk for drug-resistant disease 4.
• Rifamycin-based regimens for latent TB infection have been successful in preventing progression to TB disease, with once-weekly isoniazid and rifapentine for 12 weeks by directly observed therapy (DOT) being shown to be safe and effective 4.
• The treatment of isoniazid-resistant tuberculosis with isoniazid, rifampin, ethambutol, and pyrazinamide for 6 months has been shown to be effective, with successful outcomes in a public health tuberculosis clinic 5.

Pharmacokinetics and Determinants

• The pharmacokinetics of rifampin, isoniazid, pyrazinamide, and ethambutol in a cohort of tuberculosis patients have been evaluated, with several factors independently associated with variations in antituberculosis drug concentrations, including human immunodeficiency virus infection, formulation factors, and patient demographics 6.
• Further studies are required to assess the implications of variations in antituberculosis drug concentrations for efficacy and safety before decisions are made to change the dosing strategy in patients at risk 6.