Pharmacogenomics is application of genetic testings and gene expression data to improve the efficacy and safety of drugs. Currently, some adverse reactions exhibit strong genetic risks and genetic information are useful to stratify patients to receive better tolerate drug while maintain its efficacy and avoid the shift of the drugs choice to higher cost better profile drugs. 

The pharmacovigilance is benefit from availability of PGx testing. 

A randomized trial in Japanese demonstrated that NAT2 genotype status enable avoidance of DILI from anti-tuberculosis in slow acetylators and reduce failure rate in TB cases with rapid acetylators status by adjusting the INH dosage according to patients acetylator genotype status. (Azuma et al , Eur J Clin Pharmacol (2013) 69: 1091-1101