Table 1

Benzydamine metabolism by liver preparations

Species	System	Reference	K_m	V_max^1-a	V/K^1-b	In vitro t_1/2	CL_int′	Well-stirred CL_b
			μM		ml/min/mg	min	ml/min/kg
Human	FMO3	Lang and Rettie, 2000	80 ± 8	36 ± 2	0.04		34.0	12.6
	HLM	Stormer et al., 2000	64 ± 17	6.9 ± 3.6	0.11		101.9	16.7
Rat	RLM	Kawaji et al., 1993	15 ± 1	37 ± 3	2.47		4446.0	68.9
Human	hepatocytes					145	51.7	14.4
	HLM⁺NADPH^1-c					8.9	38.4	13.2
	HLM-NADPH					15.1	22.6	10.6
Rat	hepatocytes					2.3	3254.1	68.5

Benzydamine in vivo CL = 2.4 ml/min/kg (Chasseud and Catanese, 1985; Schoenwald et al., 1987) assuming a 70 kg human.

RLM, rat liver microsomes; HLM, human liver microsomes.
↵1-a V_max in nmol/min/mg, except FMO3 in nmol/min/nmol.
↵1-b FMO3 V/K, in ml/min/nmol, was converted to ml/min/mg assuming 80 pmol/mg human liver microsomes (Haining et al., 1997).
↵1-c HLM were prewarmed with or without NADPH present, and reaction was initiated with either NADPH or substrate.