Table 4.

Alterations in drug metabolizing enzymes observed with various liver diseases.

Phase of metabolism	Enzyme	Observed changes	References
Phase 1	CYP1A2	↓	[George et al. 1995a, 1995b; Verbeeck and Horsmans, 1998; Elbekai et al. 2004; Parkinson et al. 2004; Villeneuve and Pichette, 2004; Frye et al. 2006; Nakai et al. 2008]
	CYP2C9	↔/↓	[George et al. 1995a, 1995b; Verbeeck and Horsmans, 1998; Hasler et al. 1999; Rodighiero, 1999; Elbekai et al. 2004; Villeneuve and Pichette, 2004]
	CYP2C19	↓	[Villeneuve and Pichette, 2004; Areberg et al. 2006]
	CYP2E1	↓	[Guengerich and Turvy, 1991; George et al. 1995a; Hasler et al. 1999; Elbekai et al. 2004; Parkinson et al. 2004; Villeneuve and Pichette, et al. 2004]
	CYP3A4	↓	[George et al. 1995a, 1995b; Rodighiero, 1999; Yang et al. 2003; Elbekai et al. 2004; Villeneuve and Pichette, 2004; Nakai et al. 2008; McConn et al. 2009]
	Alcohol Dehydrogenase	↓	[Nuutinen, 1986; Vidal et al. 1990]
	Aldehyde Dehydrogenase	↓	[Nuutinen, 1986; Vidal et al. 1998]
Phase 2	Sulfation	↓	[Iqbal et al. 1990; Pacifici et al. 1990; Klaassen and Boles, 1997; Choo et al. 1999; Elbekai et al. 2004]
	Glucuronidation	↔/↓	[Hoyumpa and Schenker, 1991; Congiu et al. 2002; Elbekai et al. 2004]

CYP, cytochrome P450.