Table 3.
Nicotine intake and pharmacokinetics by e-liquid flavor during a 90-minute period of ad libitum access to e-cigarettes
| Variable | Usual brand | Test Flavors | Strawberry vs Tobacco | ||
|---|---|---|---|---|---|
|
| |||||
| Strawberry | Tobacco | ‡ Mean ratio or difference (95% CI) | F (p value) | ||
| Amount of e-liquid used (mg) | 689 (103) | 316 (53) | 242 (56) | 1.43 (0.91, 2.26) | 3.14 (0.11) |
| Amount of nicotine inhaled (mg) | 3.4 (0.5) | 5.4 (0.9) | 4.1 (0.9) | 1.45 (0.92, 2.29) | 3.41 (0.10) |
| T max (min) | 79 (5) | 80 (4) | 84 (3) | −3 (−13, 7) † | 0.56 (0.47) |
| Cmax (ng/mL) | 11.5 (1.7) | 17.1 (3.1) | 11.5 (2.3) | 1.57 (0.89, 2.77) | 3.19 (0.11) |
| C90 min (ng/mL) | 11.2 (1.7) | 16.5 (3.1) | 11.3 (2.3) | 1.56 (0.91, 2.68) | 3.43 (0.10) |
| AUC(0→90) (ng/mL•min) | 628 (102) | 951 (153) | 624 (120) | 1.66 (0.94, 2.95) | 4.07 (0.07) |
| Cmax/NIC inhaled (ng/mL/mg) | 3.5 (0.2) | 3.2 (0.3) | 3.0 (0.2) | 1.08 (0.93, 1.26 | 1.33 (0.28) |
| C90 min/NIC inhaled (ng/mL/mg) | 3.4 (0.2) | 3.1 (0.3) | 2.9 (0.2) | 1.07 (0.95, 1.21) | 1.76 (0.22) |
| AUC(0→90) per NIC inhaled (ng/mL•min/mg) | 190 (12) | 183 (12) | 164 (14) | 1.15 (0.94, 1.40) | 2.38 (0.16) |
| AUC(0→90)/e-liquid NIC (ng/mL•min/mg/mL) | 105.4 (13.8) | 47.8 (7.7) | 32.3 (6.2) | 1.61 (0.91, 2.86) | 3.59 (0.09) |
Values are presented as mean and standard error of the mean (SEM);
‡
Comparisons between the two test flavors are presented as mean ratios of strawberry to tobacco obtained from back-transform of least-square mean differences of log-transformed variables;
†
Comparisons are differences rather than ratios.