Pharmacological properties : תכונות פרמקולוגיות

Pharmacodynamic Properties

5.1.      Pharmacodynamic properties
Pharmacotherapeutic group: DIAGNOSTIC AGENTS, COLOURING AGENTS; ATC code: S01JA01.
When exposed to blue light (465-490 nm) fluorescein sodium emits a yellow-green fluorescence (520- 530 nm). This fluorescence allows the detection of pathological changes in the retinal circulation.

Pharmacokinetic Properties

5.2.      Pharmacokinetic properties
Distribution
After intravenous injection, fluorescein is quickly distributed and appears in the retinal tissue within 15- 20 seconds.
Approximately 80% of fluorescein is bound to plasmatic proteins (mainly to albumin) and 15 to 17% to erythrocytes.
Biotransformation
After intravenous administration, fluorescein is quickly transformed into fluorescein glucuronide which also has fluorescent properties.
After 4 to 5 hours, almost all plasma fluorescence is due to fluorescein glucuronide.
Plasma pharmacokinetics of fluorescein are the same in diabetic and non-diabetic patients.
Elimination
Fluorescein is excreted in the urine, as unchanged fluorescein glucuronide metabolite, within 24-36 hours after administration. The urine may attain a bright yellow colour during this period.

Plasma elimination half-lives of fluorescein and fluorescein glucuronide are about 23.5 and 264 minutes respectively.