The people identified to be most at risk of major adverse side effects in this study were:

age >60,
females,
HIV positive patients, and
Asians.It can be extremely difficult identifying which drug is responsible for which side effect, but the relative frequency of each is known. The offending drugs are given in decreasing order of frequency:

Thrombocytopenia: Rifampicin (RMP)
Neuropathy: Isoniazid (INH)
Vertigo: Streptomycin (STM)
Hepatitis: Pyrazinamide (PZA), RMP, INH
Rash: PZA, RMP, Ethambutol (EMB)Thrombocytopenia is only caused by RMP and no test dosing need be done. Regimens omitting RMP are discussed below. Please refer to the entry on rifampicin for further details. The most frequent cause of neuropathy is INH. The peripheral neuropathy of INH is always a pure sensory neuropathy and finding a motor component to the peripheral neuropathy should always prompt a search for an alternative cause. Once a peripheral neuropathy has occurred, INH must be stopped and pyridoxine should be given at a dose of 50 mg thrice daily. Simply adding high dose pyridoxine to the regimen once neuropathy has occurred will not stop the neuropathy from progressing. Patients at risk of peripheral neuropathy from other causes (diabetes mellitus, alcoholism, renal failure, malnutrition, pregnancy, etc.) should all be given pyridoxine 10 mg daily at the start of treatment. Please refer to the entry on isoniazid for details on other neurological side effects of INH. Rashes are most frequently due to PZA, but can occur with any of the TB drugs. Test dosing using the same regimen as detailed below for hepatitis may be necessary to determine which drug is responsible.
The dose for TB meningitis is dexamethasone 8 to 12 mg daily tapered off over six weeks (for those who prefer more precise dosing should refer to Thwaites et al., 2004). The dose for pericarditis is prednisolone 60 mg daily tapered off over four to eight weeks.Steroids may be of temporary benefit in pleurisy, extremely advanced TB, and TB in children:
Pleurisy: prednisolone 20 to 40 mg daily tapered off over 4 to 8 weeks
Extremely advanced TB: 40 to 60 mg daily tapered off over 4 to 8 weeks
TB in children: 2 to 5 mg/kg/day for one week, 1 mg/kg/day the next week, then tapered off over 5 weeksSteroids may be of benefit in peritonitis, miliary disease, tubercular osteomyelitis, TB osteomyelitis, laryngeal TB, lymphadenitis and genitourinary disease, but the evidence is scant and the routine use of steroids cannot be recommended. Steroid treatment in these patients should be considered on a case-by-case basis by the attending physician. The long-term impact of pleural TB on respiratory function is unknown. Therefore, such impact should be quantified first before assessing the need of further clinical trials of corticosteroids with pleural TB.Thalidomide may be of benefit in TB meningitis and has been used in cases where patients have failed to respond to steroid treatment. Non-compliance
Patients who take their TB treatment in an irregular and unreliable way are at greatly increased risk of treatment failure, relapse and the development of drug-resistant TB strains.There are variety of reasons why patients fail to take their medication.