The Science behind the Tip

Knowledge of the washout periods for topical medications is crucial for the evaluation of the effects of their withdrawal, of switching medications, or of filtration surgery and subsequent discontinuation of medical therapy. It also allows optimal timing of follow-up visits. Surprisingly few studies have been done. Generally, standard drugs have been studied and it is assumed that other drugs belonging to the same class of medication behave similarly. A wide variation among individuals exists in washout times for the longer acting topical medications.

It is important to note that prostaglandin analogues are extremely long acting. It can take 8 weeks before Xalatan® completely loses its activity.

Contributor: Ann Hoste, Antwerp

Tip Reviewer: Roger Hitchings
Tip Editors: Ann Hoste, John Salmon and John Thygesen