NEUROSYPHILIS - CURRENT DRUG-TREATMENT RECOMMENDATIONS

Neurosyphilis is a symptom of the tertiary stages of syphilis (a chron ic systemic infection of Treponema pallinum subspecies pallidum). Clas sical neurosyphilis has become a rare condition in Western countries b ecause of the use of penicillin for the treatment of early or latent s yphilis. Although textbook neurosyphilis is now uncommon, modified neu rosyphilis as a consequence of intercurrent antibiotic use for other c onditions may be more common. This latter condition is harder to diagn ose than classical neurosyphilis because of atypical clinical and cere brospinal fluid (CSF) findings. The coexistence of HIV infection and s yphilis has further complicated the picture. There have been no well c ontrolled trials of treatments for neurosyphilis. Nevertheless, the tr eatment of choice for established neurosyphilis has been shown to be b enzylpenicillin (penicillin G). The drug is administered as an intensi ve therapy of frequent intravenous high doses or high doses of an intr amuscular repository formulation with probenecid, Other agents that ca n be used include high dose amoxicillin (amoxycillin) with probenecid (but compliance cannot be monitored), tetracyclines, macrolides or cef triaxone. If the individual is HIV-positive or of unknown serostatus, benzylpenicillin should be used to prevent or treat neurosyphilis. In patients who are allergic to penicillin, rush desensitisation can be u sed to allow administration of benzylpenicillin. Alternatively, non-pe nicillin antibiotics can be used. Much work has been performed to esta blish the bactericidal concentrations of penicillin and other antibiot ics in serum and CSF. However, the significance of these values is unc ertain because the causative pathology of neurosyphilis may lie in the perivascular space. Follow-up and counselling of patients with neuros yphilis, and repeat lumbar puncture for analysis of CSF where initiall y abnormal, are recommended.