[Absorption of diphenhydramine through the urethra (author's transl)].

A new lubricant containing diphenhydramine hydrochloride has been recently introduced for catheterization procedures. Absorption of the active agent through the urethra was assessed by means of blood sample determinations. The results were compared with the already-known values after oral intake and were very low. The maximum concentration was 0.4 microgram.