Use of Ultra High Performance Liquid Chromatography-Tandem Mass Spectrometry to Demonstrate Decreased Serum Statin Levels after Extracorporeal LDL-Cholesterol Elimination

Table 2

Atorvastatin and its metabolites in waste fluids.

Samples from the procedure	Compound	Number of samples	Average (nmol/L)	Standard deviation	Median (nmol/L) (range)
LDL-apheresis	AT	15	0.28	0.20	0.22 (0.00–0.77)
	p-OH-AT	15	0.07	0.07	0.06 (0.00–0.25)
	o-OH-AT	15	0.09	0.11	0.06 (0.00–0.39)
	ATL	15	0.15	0.18	0.12 (0.00–0.74)
Hemorheopheresis	AT	7	3.04	3.58	2.57 (0.21–12.05)
	p-OH-AT	7	0.37	0.37	0.29 (0.00–1.06)
	o-OH-AT	7	1.72	1.33	1.38 (0.05– 4.11)
	ATL	7	2.52	1.85	2.23 (0.96–6.38)
Both procedures (Hemorheopheresis +LDL-apheresis)	AT	22	1.34	2.51	0.34 (0.00–12.05)
	p-OH-AT	22	0.19	0.27	0.08 (0.00–1.06)
	o-OH-AT	22	0.71	1.13	0.12 (0.00–4.11)
	ATL	22	0.91	1.51	0.18 (0.00–6.38)

p-OH-AT: p-hydroxyatorvastatin, o-OH-AT: o-hydroxyatorvastatin, AT: atorvastatin, ATL: atorvastatin lactone.