Table 1.

Plasma and urinary concentrations of nicotine and cotinine in users of nicotine delivery systems (with comparison to conventional cigarettes).

	Blood concentration range (ng/ml)		Urinary concentration range (ng/ml)
Nicotine-containing product	Nicotine	Cotinine	Nicotine	Cotinine
NRT
Dermal patch	6–28*,†,‡,¶	161–170‡	–	–
	7–25¶	80–300¶		300–1300¶
Sublingual tablet	7–30*,†	–	–	–
Nasal spray	3–20*,†	170 ± 95§	–	–
Gum	7–43*,†	–	–	900∥
Inhaler	2–40*,†	–	–	–
Lozenge	35†	–	–	900∥
ENDS	9–24#,**,††,‡‡	99–156¶¶	604–1250§§	1420–2480§§
Conventional cigarette	10–50*	184 ± 106∥∥	1191 ± 1145∥∥	1149 ± 736∥∥

*From Schneider et al. (2001) (review article).

†From Shiffman et al. (2005) (review article; maximum concentrations).

‡From Gourlay and Benowitz (1996) (after 4–6 h of patch application).

¶From Lawson et al. (1998a, 1998b) (approximate values for 11-mg to 44-mg patch users).

§From Benowitz et al. (1997) (mean ± SD).

∥From Kotlyar et al. (2011) (approximate values, 4-mg lozenges or gums).

#From Ramoa et al. (2015).

**From Lopez et al. (2015).

††From D'Ruiz et al. (2015) (after 90 min of ad libitum use).

‡‡From Dawkins and Corcoran (2014) (ad libitum).

¶¶From Pacifici et al. (2015) (switched to e-cigarette for 1–8 months).

§§From Hecht et al. (2015) (95% confidence interval).

∥∥From Roethig et al. (2009) (population estimates; urine data previously unpublished; mean ± SD).