| Side Effects | Definition |
| Gastro-intestinal | Nausea, vomiting or pain abdomen |
| Diarrhoea arthralgia | Documented by physician Joint pains with or without arthritis |
| Nephrotoxicity | Elevation of Serum creatinine levels above the normal values* |
| Oto-vestibular toxicity | 1) Hearing loss confirmed by physical examination or audiometry 2) Vestibular side effects like dizziness/vertigo/tinnitus. |
| Dermatologic | Any drug reaction felt to be related to anti-tuberulous medication, as documented by TB physician/dermatologist |
| Peripheral neuropathy | Symptoms & findings consistent with neuropathy eg: numbness, tingling or burning in trunks or extremities, diagnosed by physician or nerve conduction studies |
| Seizure | Seizure activities witnessed or unwitnessed |
| Hypothyroidism | Serum TSH levels >10 micro IU/ml |
| Hepatotoxicity | Elevation of transaminases thrice the upper normal limit or/and bilirubin twice the upper normal limit* |
| Ocular | Visual changes suggestive of optic neuritis or loss of color vision confirmed by an ophthalmologist |
| Psychiatric | Presence of one or more of the following Depression, adjustment disorders, anxiety/psychosis suicidal tendencies as diagnosed by psychiatrist |