Chemotherapy of osteoarticular tuberculosis

Tuberculosis (TB) of the bones and joints is rampant in India with the dorsolumbar spine as the most common site of osseous involvement. For diagnosis, clinical suspicion needs to be confirmed through appropriate laboratory and imaging investigations, and increasingly nowadays, nucleic acid amplification techniques. Chemotherapy remains the cornerstone of management complemented by rest, nutritional support and splinting, as necessary. Operative intervention is required if response to chemotherapy is unsatisfactory and for spinal stabilization. The drugs and regimens are fundamentally similar to those for pulmonary TB. However, there is lack of consensus on the appropriate duration of treatment. The prevailing practice of extending treatment till radiological evidence of healing is complete, may be unnecessary in view of recent reports that 6-9 months of therapy is sufficient for the majority of cases. Relapse rates are not drastically improved by extending treatment to 12 months or even longer, except perhaps in pediatric cases. However, prolonged treatment may be required if surgical debridement is indicated but cannot be done. Multidrugresistant TB should be suspected if disease activity shows no signs of abating after 4-6 months of uninterrupted therapy. These cases are therapeutically challenging and will require second line or experimental antiTB drugs, supported by resistance testing where feasible. Coexistent HIV/AIDS may also necessitate prolonged treatment. Interactions between first line antiTB drugs and antiretroviral medication can complicate matters. Close monitoring is essential in all cases, with dechallenge and cautious reinstitution of drugs in the event of toxicity. While awaiting the arrival of long overdue new antiTB medication, existing drugs and regimens must be used in an informed manner with emphasis on patient compliance.