Oral amoxycillin, an alternative treatment for neurosyphilis

Area of Science:

• Infectious Diseases
• Pharmacology
• Neurology

Background:

• Neurosyphilis, a late-stage manifestation of syphilis infection, requires effective treatment to prevent severe neurological damage.
• Penicillin G has been the standard treatment, but concerns about resistance and administration routes exist.

Purpose of the Study:

• To evaluate the efficacy of oral amoxycillin in achieving treponemicidal concentrations in cerebrospinal fluid (CSF) for treating neurosyphilis.

Main Methods:

• A rabbit model with experimental orchitis was used to establish a treponemicidal serum amoxycillin concentration (0.11 g/l).
• Seventeen neurosyphilis patients received oral amoxycillin (2 g TID) plus probenecid (500 mg BID).
• CSF amoxycillin concentrations were measured to assess therapeutic levels.

Main Results:

• The established treponemicidal serum amoxycillin concentration was 0.11 g/l.
• Patients treated with oral amoxycillin and probenecid achieved treponemicidal amoxycillin concentrations in their CSF.
• This indicates successful penetration and sustained therapeutic levels in the central nervous system.

Conclusions:

• Oral amoxycillin, when administered with probenecid, can achieve effective CSF concentrations for treating neurosyphilis.
• This regimen presents a viable and potentially more accessible alternative to traditional intravenous treatments for neurosyphilis.