Probenecid is a uricosuric drug, which inhibits the renal excretion of procaine penicillin via inhibition of the organic anion transporter (OAT-1) system in the proximal renal tubule producing higher plasma and cerebrospinal fluid (CSF) penicillin levels.1 2 Oral probenecid is recommended to be used with intramuscular procaine penicillin for the treatment of neurosyphilis.

Rates of syphilis and neurosyphilis have increased significantly over the past 20 years particularly in men who have sex with men (MSM). There …