Table 4.

Summary of studies applying metabolomics for biomarker search of drug addiction.

Parent compound	Changed endogenous metabolites	Involved biological pathways	Experimental setup	Sample prep	Analytical conditions	Data evaluation	Reference
Cocaine	N-methylserotonin Guanine Hypoxanthine Anthranilate Xanthine	Tryptophan metabolism Purine metabolism	Targeted Human plasma Cocaine-dependent (n = 18) vs. healthy controls (n = 10)	PP	Electrochemical detection electrochemical array platform LCECA	R	Patkar et al., 2009
Crack	Lactate Long chain fatty acids acylated carnitines Histidine and tyrosine	Nutritial behavior	Untargeted Human serum Crack-dependent vs. control group n = 44 per group	Dilution	NMR 1H-NMR (1D, 600.173 MHz) T2-edited spectra of 1H NMR HSQC experiments for 1H–13C correlations		Costa et al., 2018
Heroin	myo-inositol-1-P threonate 9-z-hexadecenoic acid hydroxyproline		Untargeted Rat serum/urine Control vs. heroin-treated n = 6 per group	PP Derivatization CH3-O-NH2 MSTFA	GC-MS DB5-MS (10 m × 0.18 mm) He EI/TOF Fullscan	SIMCAP 11	Zheng et al., 2013
MA	Acute: Alanine Glycine Ornithine Asparagine Valine Isoleucine Leucine Serine Proline Threonine Methionine Citrulline Tryptophan Glutamine Glutamate Asparate Lysine Citrate 2-ketoglutarate Succinate Fumarate Malate Pyruvate Long term (5 days): Alanine Glycine Lysine Threonine Ornithine, hydroxyproline citrulline Fumarate Pyruvate Succinate Citrate 3-hydroxybutyrate 5-hydroxyindoleacetic 2 days after withdrawal Isoleucine Palmitic acid Creatinine Citrate 2-ketoglutarate Lactate	Energy metabolism Amino acid metabolism TCA cycle Lipids and free fatty acids	Untargeted Rat serum/urine Control vs. MA-treated n = 6 per group	PP Derivatization CH3-O-NH2 MSTFA	GC-MS RTx-5MS column (30 m × 0.25 mm) He EI Fullscan	SIMCA-P 13	Zheng et al., 2014