Duration of Treatment
The optimal duration of therapy for MDR-TB has not been clearly established and duration remains questionable. However, several authorities including the WHO recommend treatment with anti-tubercular Drugs for a
period of at least 1 8-24 months after sputum conversion or 12 months after
sputum culture becomes negative to prevent relapse. Injectables are preferably
used for at least six months and at least four months after the patients first
become and remain sputum smear or culture negative.
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Monitoring Response to Treatment
Patients receiving treatment for MDR-
TB should be
closely followed up. Sputum specimens should be obtained for smear and culture
monthly during intensive phase of therapy. After sputum conversion, smear
examination and culture are done once in three months till the end of therapy.
Markers of response in order of reliability are bacteriology of sputum,
radiology followed by the clinical picture.'
The following parameters should be frequently reviewed to assess the response to
treatment:'
- Clinical (e.g., fever, cough, sputum production, weight gain)
β’ Radiological (e.g., chest radiograph)
- Laboratory (erythrocyte sedimentation rate)
- Microbiological (e.g., sputum smear and culture)
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In addition, considerable attention must be focused on monitoring the adverse drug reactions, which often develop with the second-line antituberculosis drugs .
Majority of the patients who respond to treatment begin to show favourable signs
of improvement by about four to six weeks following initiation of treatment.
Failure to show positive trend may alert the clinician to resort to other
measures.
Extra- Pulmonary MDR-TB Treatment
The treatment strategy is the same for patients with pulmonary and extra-
pulmonary MDR-
TB. If the patient has symptoms suggestive of central nervous system involvement and is infected with MDR-
TB, the regimen should use drugs that have adequate penetration into the central nervous system. Rifampicin, isoniazid, pyrazinamide, prothionamide/ ethionamide and cycloserine have good penetration; kanamycin, amikacin and capreomycin penetrate effectively only in the presence of meningeal inflammation; PAS and ethambutol have poor or no penetration.
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Surgery
Surgery should be considered in patient with persistent culture positive MDR-
TB despite effective medical treatment. If the patient has localized disease, reasonable lung function and only two or three (weak) drugs
available, surgery should be seriously considered. Resectional surgery is done
as an adjunct to medical treatment. Feasibility and success of surgery appear to
be substantially enhanced by nutritional support. In one of the recent studies
use of resection surgery and fluoroquinolone therapy was associated with
improved microbiological and clinical outcome.16 Even with successful resection,
additional 12-24 months of chemotherapy should be given.