What is the recommended treatment for HIV (Human Immunodeficiency Virus) and TB (Tuberculosis) co-infection?

Treatment of HIV and TB Co-infection

For patients co-infected with HIV and TB, treatment should include a rifabutin-based regimen for TB when the patient is receiving antiretroviral therapy with protease inhibitors or non-nucleoside reverse transcriptase inhibitors, along with early initiation of antiretroviral therapy within 2-8 weeks of TB treatment, particularly within 2 weeks for those with CD4 counts below 50 cells/mm³. 1

TB Treatment Regimens for HIV Co-infected Patients

For Patients Already on Antiretroviral Therapy:

1. Rifabutin-based regimen (preferred) 2, 1:

   • Initial phase (2 months): Isoniazid, rifabutin, pyrazinamide, and ethambutol
   • Continuation phase (4 months): Isoniazid and rifabutin
   • Dosage adjustment for rifabutin:
     • 150 mg daily when used with indinavir, nelfinavir, or amprenavir
     • 450 mg daily when used with efavirenz
     • 300 mg twice weekly regardless of antiretroviral medication

2. Alternative non-rifamycin regimen (when rifamycins are contraindicated) 2, 1:

   • Initial phase (2 months): Isoniazid, streptomycin, pyrazinamide, and ethambutol
   • Continuation phase (7 months): Isoniazid, streptomycin, and pyrazinamide
   • Total duration: 9 months

For Patients Not Yet on Antiretroviral Therapy:

• Standard rifampin-based regimen can be used initially 2
• Initial phase (2 months): Isoniazid, rifampin, pyrazinamide, and ethambutol
• Continuation phase (4 months): Isoniazid and rifampin

Timing of Antiretroviral Therapy Initiation

The optimal timing for starting antiretroviral therapy depends on CD4 count 1, 3:

• CD4 < 50 cells/mm³: Start ART within 2 weeks of TB treatment (reduces mortality by 6%) 3
• CD4 > 50 cells/mm³: Start ART within 8 weeks of TB treatment 1, 3
• TB meningitis: Consider delaying ART regardless of CD4 count due to increased risk of adverse events 4

Monitoring and Management

1. Directly observed therapy (DOT) is strongly recommended for all HIV-TB co-infected patients 2, 1

2. Regular monitoring 1:

   • Monthly clinical evaluation
   • Sputum microscopy at 2 months, 5 months, and end of treatment
   • Monitor for drug interactions and adverse effects
   • Follow-up of viral load and CD4 count

3. Management of paradoxical reactions 1:

   • More common in HIV-infected patients starting ART
   • Symptoms: fever, increased lymphadenopathy, worsening pulmonary infiltrates
   • Mild cases: symptomatic treatment
   • Severe cases: consider prednisone or methylprednisolone (1 mg/kg)

Drug Interactions and Special Considerations

1. Pyridoxine supplementation (25-50 mg daily) for all patients receiving isoniazid to prevent neurological side effects 1

2. Drug-resistant TB 1:

   • Assess likelihood of drug resistance based on history and community prevalence
   • For MDR-TB, use at least four drugs to which organisms are susceptible for 18-24 months

3. Pregnant women 1, 5:

   • Treat without delay using rifamycin-based regimens
   • Pyrazinamide can be used despite previous concerns about teratogenicity
   • Avoid aminoglycosides due to risk of congenital deafness

Common Pitfalls and Caveats

1. Do not exclude rifamycins from TB treatment regimens solely due to concerns about drug interactions, as this may worsen outcomes 1

2. Beware of malabsorption issues in advanced HIV disease, which may affect drug levels 1

3. Watch for immune reconstitution inflammatory syndrome (IRIS) when starting ART, especially in patients with low CD4 counts (increased risk by 6%) 3

4. Avoid delaying ART initiation beyond recommended timeframes, as this increases mortality risk in patients with low CD4 counts 6

5. Consider integrated TB-HIV care using a single facility and healthcare provider to improve outcomes and reduce delays in treatment 7

By following these guidelines, clinicians can effectively manage the complex treatment needs of patients co-infected with HIV and TB, reducing mortality and improving long-term outcomes.