What is a procaine reaction to neurosyphilis therapy and how is it prevented?

Updated: Jul 17, 2018
  • Author: Richard P Knudsen, MD, FAAN, FAAP; Chief Editor: Niranjan N Singh, MBBS, MD, DM, FAHS, FAANEM  more...
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Prevention of this rare and alarming reaction involves aspiration into the syringe following insertion of the needle prior to intramuscular injection. Should any blood be present, the needle should be re-placed in a different site. In that the onset of symptoms is early, exclude anaphylaxis. If the patient is experiencing anaphylaxis, administer epinephrine and antihistamines. Advise the patient to calm down, and offer verbal reassurance. Restrain the patient if necessary. Prescribe diazepam at 10 mg per rectum, intramuscularly, or intravenously as needed for convulsions and/or overarousal.

Inadvertent intravenous injection of procaine PCN can induce manifestations of psychological disturbance. The pathogenesis of the reaction is not well understood. It is characterized by fever and severe anxiety, including fear of impending death. Hallucinosis, mania, or convulsions may occur immediately after injection and last less than 20 minutes. Hyperventilation and circulatory collapse have been reported. This reaction can be minimized by using the aspiration technique.

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