Binding affinities and dissociation half-lives (t1/2) of tiotropium and ipratropium
| Receptor | Tiotropium | Ipratropium | ||
| KD nM | t1/2 h | KD nM | t1/2 h | |
| M1 | 0.041 | 14.6 | 0.183 | 0.110 |
| M2 | 0.021 | 3.6 | 0.195 | 0.035 |
| M3 | 0.014 | 34.7 | 0.204 | 0.260 |
KD: kinetically determined dissociation constant. Reprinted from [16] with permission from the publisher.