Treatment Protocol for Tuberculosis (TB) Meningitis
For TB meningitis, treatment should consist of rifampicin and isoniazid for 12 months, supplemented by pyrazinamide and a fourth drug (either streptomycin or ethambutol) for at least the first two months, along with adjunctive corticosteroid therapy for moderate to severe disease. 1
Initial Treatment Regimen
The treatment of TB meningitis requires a longer duration compared to pulmonary TB due to the severity of the disease and CNS penetration considerations:
Initial intensive phase (first 2 months):
Continuation phase (10 additional months):
- Isoniazid and rifampicin for a total treatment duration of 12 months 1
Drug Penetration Considerations
Drug selection for TB meningitis is influenced by CNS penetration:
- Isoniazid, pyrazinamide, and ethionamide penetrate well into the cerebrospinal fluid 1
- Rifampicin penetrates less well but is still essential for treatment 1
- Streptomycin and ethambutol only penetrate adequately when meninges are inflamed in early treatment stages 1
Adjunctive Therapy
Corticosteroids play a crucial role in reducing mortality and neurological sequelae:
- Recommended for moderate to severe disease (stages II and III) 1, 4
- Dexamethasone (6-12 mg/day) or prednisone (60-80 mg/day) for 6-8 weeks with gradual tapering 1, 4
- Benefits include reduced mortality, decreased neurological sequelae, and prevention of complications 1, 4
Disease Staging and Management
TB meningitis severity classification (British Medical Research Council system) guides management:
- Stage I: Fully conscious, rational, no neurological signs 4
- Stage II: Confused or has neurological signs (cranial nerve palsy, hemiparesis) 4
- Stage III: Comatose or stuporous with severe neurological signs 4
Corticosteroids are particularly beneficial for Stage II and III disease 4
Special Populations
Children
- Treatment should be for a minimum of 12 months with rifampicin and isoniazid 1
- Initial 2 months should include pyrazinamide and a fourth drug (streptomycin or ethambutol) 1
- Dosing should be weight-based and may need recalculation with weight gain 1
Pregnant Women
- Streptomycin should be avoided as it may cause congenital deafness 2
- Pyrazinamide is generally not recommended due to inadequate teratogenicity data 2
- Initial treatment should consist of isoniazid and rifampicin with ethambutol added if primary isoniazid resistance is a concern 2
Drug Resistance Considerations
- If drug resistance is suspected or confirmed, treatment must be individualized based on susceptibility testing 2, 5
- In areas with high drug resistance (>4%), a fourth drug should be added to the initial regimen 4
- For multidrug-resistant TB meningitis, consultation with an expert is strongly recommended 2
Monitoring and Follow-up
- Regular clinical assessment for neurological improvement or deterioration 1
- Monitor for drug-related adverse effects, particularly hepatotoxicity with isoniazid, rifampicin, and pyrazinamide 1
- Watch for complications such as hydrocephalus, which may require neurosurgical intervention 4
Common Pitfalls to Avoid
- Delaying treatment while awaiting confirmatory tests - treatment should begin as soon as clinical suspicion is supported by initial CSF studies 5
- Inadequate duration of therapy - TB meningitis requires longer treatment than pulmonary TB 1
- Premature or rapid tapering of corticosteroids, which may lead to recurrence of CNS inflammation 4
- Failure to consider drug resistance, especially in high-prevalence areas 4, 5
- Inadequate monitoring for complications like hydrocephalus, which may require specific interventions 4
While some studies have explored shorter treatment regimens for TB meningitis 6, 7, the current standard remains 12 months of therapy due to the severity of the disease and risk of neurological sequelae 1.