TABLE 1.
RESPONSE THRESHOLD FOR THE VARIOUS TUSSIVE CHALLENGES IN 10 NORMAL SUBJECTS
| Tussive Agent | Response | Baseline | At 1 Hour | After Subthreshold Cinnamaldehyde | After Diluent |
|---|---|---|---|---|---|
| Cinnamaldehyde (mM) | C2 | 200 | 275 | n/a | n/a |
| C5 | 313 | 388 | n/a | n/a | |
| Citric acid (mM) | C2 | 125 | 125 | 125 | 94 |
| C5 | 200 | 250 | 250 | 250 | |
| Capsaicin (μM) | C2 | 4 | 4 | 8 | 4 |
| C5 |
12 |
16 |
16 |
16 |
Shown are median C2 and C5 values at baseline and 1 hour after baseline for cinnamaldehyde, citric acid, and capsaicin as well as median C2 and C5 values after inhalation of subthreshold TRPA1 agonist and diluent. C2 is the concentration inhaled at which two or more coughs were recorded and C5 is the concentration at which five or more coughs were recorded. In the citric acid group the concentration needed to induce cough was significantly greater at 1 hour (P = 0.02).