Table 2.
Change from baseline in weekly average pain scores.
| TTX Dosage | |||||
|---|---|---|---|---|---|
| Time Period | 7.5 µg BID (N = 25) |
15 µg BID (N = 24) |
30 µg QD (N = 25) |
30 µg BID (N = 26) |
Placebo (N = 25) |
| Days 1–7, n | 25 | 24 | 24 | 25 | 25 |
| Mean change in NPRS (±SD) | −0.8 (±1.0) | −0.9 (±0.8) | −1.0 (±1.6) | −1.2 (±1.6) | −0.9 (±1.1) |
| p-value for Difference in LSM vs. Placebo | 0.84 | 0.84 | 0.66 | 0.35 | |
| Days 8–14, n | 23 | 24 | 24 | 25 | 24 |
| Mean change in NPRS (±SD) | −1.2 (±1.4) | −1.2 (±1.1) | −1.5 (±1.8) | −1.4 (±1.8) | −1.4 (±1.7) |
| p-value for Difference in LSM vs. Placebo | 0.57 | 0.61 | 0.69 | 0.94 | |
| Days 15–21, n | 22 | 22 | 23 | 23 | 25 |
| Mean change in NPRS (±SD) | −1.2 (±1.5) | −1.3 (±1.6) | −1.7 (±2.0) | −1.6 (±1.6) | −1.4 (±1.9) |
| p-value for Difference in LSM vs. Placebo | 0.90 | 0.85 | 0.58 | 0.90 | |
| Days 22–28, n | 21 | 21 | 23 | 24 | 25 |
| Mean change in NPRS (±SD) | −1.3 (±1.4) | −1.1 (±1.6) | −1.7 (±2.3) | −1.5 (±1.8) | −1.3 (±2.1) |
| p-value for Difference in LSM vs. Placebo | 1.0 | 0.68 | 0.58 | 0.92 | |
NPRS: Numerical Pain Rating Scale; LSM: least squares mean; SD: standard deviation; TTX: tetrodotoxin; BID: twice daily; QD: once daily; n: number of subjects. A comparison of least squares mean differences (treatment—placebo) using a mixed-effect model repeated measure model (with treatment as the main effect, gender, baseline NPRS score, week and treatment-by-week interaction as covariates) found no statistically significant differences.