INH is the single most effective drug. It can be given in a single daily dose of 5 mg/kg in adults and 10 mg/kg in children. Its most important adverse effects are neuropathy and hepatitis, particularly in alcoholics. Neuropathy can be prevented by the administration of 50 mg pyridoxine daily. In patients who develop the symptoms of hepatitis or who have abnormal liver function tests, INH should be discontinued. The usual dose of RMP is 10 mg/kg daily for adults, 15 mg/kg for children. Ethambutol is given in a single daily dose of 15 mg/kg. The dosage of ETA is 15 to 25 mg/kg daily for adults; because of its tendency to produce gastric irritation, it is given in divided doses, after meals. The latter two drugs (EMB and ETA) may cause optic neuropathy, so that patients taking them should have regular examinations of visual acuity and red-green color discrimination. Ethambutol dependably causes optic neuropathy when used in doses above 20 m/kg and is a major cause of preventable optic neuropathy in developing countries. Renal failure and weight loss are risks for toxic levels of the drug. Pyrazinamide is given once daily in doses of 20 to 35 mg/kg. Rash, gastrointestinal disturbances, and hepatitis are the main adverse effects. Except for INH, all these drugs can be given only orally or by stomach tube. INH and rifampin may be given parenterally.
Corticosteroids may be used in patients whose lives are threatened by the effects of subarachnoid block or raised intracranial pressure but only in conjunction with antituberculous drugs. A randomized study conducted in Vietnam, including patients with and without HIV, showed that the addition of intravenous dexamethasone (0.4 mg/kg daily for a week and then tapering doses for 3 to 6 weeks) reduced mortality from 41 percent to 32 percent but had no effect on residual disability (Thwaites et al).
Intracranial tuberculoma calls for a similar course of antibiotics, as outlined above. Under the influence of these drugs, the tuberculoma(s) may decrease in size and small ones ultimately disappear or calcify, as judged by the CT scan; if they do not, and especially if there is “mass effect,” excision may be necessary. Patients with spinal osteomyelitis or localized granulomas with instability or spinal cord compression (Pott paraplegia) should be explored surgically after an initial course of chemotherapy, and an attempt should be made to excise the tuberculous focus. We have, however, dealt successfully with tuberculous osteomyelitis of the cervical spine (without significant abscess or cord compression) by immobilizing our patient in a hard collar and administering triple-drug therapy (at the suggestion of the patient’s father, who was a physician in India), once it was established that the spinal column was stable, the collar could be removed. Thus, flexion–extension x-rays can be valuable if they can be obtained safely.