Pain at the intravenous injection site is least with which agent?

Pain at the intravenous injection site is least with which agent?

• A. Diazepam
• B. Etomidate
• C. Propofol
• D. Thiopental

Answer: (D)

Pain at an IV injection site depends on how irritating the drug solution is to the venous endothelium and surrounding tissues. Propofol is well known for causing significant injection pain because its lipid emulsion and components readily irritate the vein and can trigger local mediator release, leading to a burning sensation. Etomidate can cause some venous irritation as well, though typically less than propofol. Diazepam given IV often uses solvent systems that can irritate the vein and can be painful in some patients. Thiopental, by contrast, tends to be relatively non-irritating to the vein, so it produces the least pain on injection among these options.

Pain at an IV injection site depends on how irritating the drug solution is to the venous endothelium and surrounding tissues. Propofol is well known for causing significant injection pain because its lipid emulsion and components readily irritate the vein and can trigger local mediator release, leading to a burning sensation. Etomidate can cause some venous irritation as well, though typically less than propofol. Diazepam given IV often uses solvent systems that can irritate the vein and can be painful in some patients. Thiopental, by contrast, tends to be relatively non-irritating to the vein, so it produces the least pain on injection among these options.