Adverse toxic reaction to aqueous procaine penicillin G

Aqueous procaine penicillin G therapy is frequently used in ambulatory care settings and clinicians have long been alerted to the potential allergic reactions that may occur with this therapy; however, the nonallergic toxic reaction has not been as widely publicized. A possible psychotic-like, pseudoanaphylactic reaction may occur within 60 seconds following an injection of aqueous procaine penicillin G. Two case reports and a review of the literature will be presented to alert clinicians to this reaction. Suggestions for management will also be offered.