Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
Pain tolerance in the Cold Pressor Test at baseline and the three testing periods during pharmacokinetically tailored IV infusion of fentanyl on pre- (closed symbol) and post- (open symbol) treatment days in the placebo (blue squares) and St. John’s wort (red circles) groups (n = 8 in each). Results are the mean ± SD.
