Therapeutic drug monitoring (TDM) indications**
| TDM indication (n=80) | N (%) | Effects on pharmacokinetics of anti-TB drugs |
| Diabetes mellitus | 6 (7.5) | Diabetes induced gastroparesis leading to either delayed absorption, malabsorption or altered clearance of anti-TB drugs |
| Concurrent HIV infection | 6 (7.5) | Reduced exposure of anti-TB drugs |
| Gastric ulcer | 1 (1.3) | Interference with absorption of anti-TB drugs |
| Liver cirrhosis | 1 (1.3) | Altered drug metabolism, prolonged effect of parent drug, reduced effect of prodrugs, increase in toxic metabolites |
| Impaired renal clearance | 1 (1.25) | Over exposure of renally cleared drugs, increased toxicity, require dose reduction |
| Slow treatment response (n=73) | 8 (11) | Possibly suboptimal exposure of anti-TB drugs due to interindividual variabilities |
*Indications based on references 16 21.
TB, tuberculosis.