Drug protocols in extra pulmonary TB
Extrapulmonary TB is a paucibacillary condition and the yield of positive smear or culture may be low (30-50%). Conventionally, extra pulmonary tuberculosis is classified into severe and non- severe forms. Meningeal tuberculosis, neurouberculosis, spinal tuberculosis, abdominal tuberculosis, bilateral pleural effusion, pericardial effusion, and bone and joint tubersulosis at more than one site are classified as severe forms of the diseases. Disease occurring at other sites are classified as non-severe forms.
Diagnosis of extrapulmonary tuberculosis demands a high index of suspicion. In developing countries the problems of diagnosis are compounded by a lack of diagnostic resources. Thus, tuberculosis may not be considered in differential diagnosis and this may result in delay or deprivation of treatment. On the other hand, empirical treatment without pathological and/or bacteriological confirmation is also common.
Any treatment effective for pulmonary tuberculosis is effective for extrapulmonary TB. Short course chemotherapy regimens containing 3 or 4 powerful bactericidal drugs in the initial 2 or 3 months, followed by 2 or 3 drugs in the following 4 to 6 months, have been found to be very effective in all forms of extra pulmonary TB. Short course regimens consisting of sterilizing drugs such as rifampicin (R) and pyrazinamide (Z) are now universal in the treatment of extra pulmonary tuberculosis. In the past 20 years a large number of highly effective regimens with different drug combinations for treating pulmonary and extrapulmonary forms of tuberculosis have been evolved through controlled clinical trials. Similarly studies done at the Tuberculosis Research Centre, Madras, on TB lymphadenitis, TB meningitis, TB abdomen, TB spine, Pott’s paraplegia, TB skin and brain tuberculoma have given excellent results with regimens containing rifampicin, isoniazid and pyrazinamide for 6 to 9 months (see Table). Based on the findings of various trials, 6 to 9 months of treatment is recommended in immunocompetent individuals. Thus rifampicin, INH and pyrazinamide with either ethambutol or streptomycin are recommended in the frist phase for 2 months followed by rifampicin and INH for 4 to 7 months in the follow-up phase. Chemotherapy is given for 9 or 12 months in meningitis and in some cases of lymphadenitis and bone and joint TB. If initial drug resistance is suspected, or the disease is severe, either stremptomycin or ethambutol, should be added to the first phase of treatment.
Treatment of extrapulmonary tuberculosis yields good results in most cases. However, in meningitis and spinal tuberculosis (Pott’s disease) the outcome usually depends on early diagnosis. In tuberculous meningitis outcome is related to the stage of the disease at the start of treatment even when short course chemotherapy is used.
In the RNTCP, severe forms of extrapulmonary disease are classified as category I and therefore received treatment exactly as smear positive pulmonary tuberculosis patients. Other forms of extrapulmonary disease are usually classified as category III which uses only three drugs in the intensive phase.
Other treatment considerations:
Corticosteroids are not recommended for routine use, but have been shown to be valuable massive tuberculous pleural effusion, meningitis, pericarditis and brain tuberculoma. In TB meningitis, steroids given in the initial phase have been shown to have a significant effect on mortality rate and neurologic sequelae. In TB affecting serosal surfaces, steroids help in faster reabsorption of fluid and in preventing adhesions.
A number of surgical procedures were practiced for TB spine and TB lymphadenitis in the prechemotheraphy era. However with the introduction of short course chemotherapy medical treatment is the method of choice for most forms of extrapulmonary tuberculosis. Only a minority of cases need surgical intervention nut surgical diagnostic procedures are often useful. Surgery is indicated in selected few who are not responding to medical treatment and in patients with complications.
Treatment Regimens recommended for extrapulmonary TB
|TRC studies||Regimens|| Duration
|TB Spine||6RH7 OR 9RH7||6 or 9|
|American Academy of Ped||2SHRZ/10RH||9 or 12*|
|American Thoracic Society||2HRZ/4RH||6 or 12*|
* For Bone and Joint and miliary TB
** Numbers preceding drug names indicate duration in months;
subscripts indicate rhythm of administration/Number of days per week
(H=Isoniazid, S=Streptomycin; R=Rifampicin; E=Ethambutol; Z=Pyrazinamide)
Dr. V. Kumaraswami
Email : [email protected]