After a course of treatment for neurosyphilis, do you administer an additional IM dose of penicillin G one week after finishing the course of IV penicillin therapy?

Excellent question. This has been the topic of a never-ending (if somewhat behind-the-scenes) debate among syphilis experts for decades. In fact, it came up for discussion just a few days ago after a presentation on syphilis at IDWeek in Boston, the Infectious Disease Society of America's annual conference.

There are no data at all on whether there is benefit (e.g. in preventing later relapse) in adding low-dose but long-acting penicillin, i.e. benzathine pen G, following 10-14 days of IV penici...