Table 5.

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.