Plasma AVP after intravenous chlorpropamide.

The proposed ADH-releasing capacity of chlorpropamide was tested after intravenous administration of the drug to nine healthy fasted volunteers. When compared with the placebo experiment, no evidence for increased ADH release was found. On the contrary, the AVP values measured after chlorpropamide injection were slightly lower during the first 2 h than after the saline injection. Serum chlorpropamide concentration was also measured. After a rapid distribution phase, a slow elimination phase followed. The calculated t 1/2 for distribution phase was 1.00 +/- 0.26 hrs (mean +/- s.e.m.).