What is the treatment for syphilis?

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Last updated: March 11, 2025View editorial policy

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From the Guidelines

Syphilis is treated with antibiotics, primarily penicillin, with the most recent and highest quality study 1 supporting the use of benzathine penicillin G as the preferred treatment for all stages of syphilis.

Treatment Recommendations

For primary, secondary, or early latent syphilis (less than one year duration), a single intramuscular injection of benzathine penicillin G 2.4 million units is the recommended treatment 1. For late latent syphilis (more than one year duration) or syphilis of unknown duration, the treatment consists of three weekly intramuscular injections of benzathine penicillin G 2.4 million units 1. For neurosyphilis or ocular syphilis, intravenous aqueous crystalline penicillin G 3-4 million units every 4 hours for 10-14 days is recommended 1.

Alternative Treatments

For patients allergic to penicillin, doxycycline 100 mg orally twice daily for 14 days (early syphilis) or 28 days (late syphilis) can be used, though it's less effective 1. Pregnant women with penicillin allergies should undergo desensitization as penicillin is the only proven effective therapy during pregnancy 1.

Follow-up and Partner Treatment

After treatment, follow-up blood tests are necessary to ensure the infection is clearing 1. Sexual partners should also be tested and treated if necessary 1. Penicillin works by interfering with the cell wall synthesis of the Treponema pallidum bacteria that causes syphilis, effectively killing the organism and stopping the progression of the disease 1.

Key Considerations

The most recent study 1 provides the strongest evidence for the treatment of syphilis, and its recommendations should be followed to ensure the best outcomes for patients. It's essential to note that while alternative treatments are available, penicillin remains the preferred treatment for all stages of syphilis 1. By following these treatment recommendations and considering the latest evidence, healthcare providers can effectively manage syphilis and improve patient outcomes.

From the FDA Drug Label

Syphilis–early: Patients who are allergic to penicillin should be treated with doxycycline 100 mg, by mouth, twice a day for 2 weeks Syphilis of more than one year’s duration: Patients who are allergic to penicillin should be treated with doxycycline 100 mg, by mouth, twice a day for 4 weeks.

The treatment for syphilis is doxycycline 100 mg, by mouth, twice a day for 2 weeks for early syphilis and for 4 weeks for syphilis of more than one year’s duration in patients who are allergic to penicillin 2.

From the Research

Treatment Options for Syphilis

The treatment for syphilis typically involves the use of antibiotics, with penicillin being the primary choice [ 3 ]. The specific type of penicillin used can vary, with benzathine penicillin G being a common option for early and late syphilis [ 3 ].

Alternative Treatments

For patients who are allergic to penicillin or cannot take it for other reasons, alternative treatments are available. These can include:

  • Doxycycline, which has been shown to be effective in treating early syphilis [ 4, 5 ]
  • Tetracycline, which can be used as a second-line treatment [ 5 ]
  • Other antibiotics, such as erythromycin or ceftriaxone, may also be considered in certain cases [ 6, 7 ]

Treatment Schedules and Follow-up

The treatment schedule for syphilis can vary depending on the stage of the disease and the specific antibiotic being used. Follow-up care is an essential part of treatment, with patients typically being monitored for at least 24 months after treatment [ 6 ]. This can include regular blood tests to check for signs of the infection, as well as monitoring for any potential side effects of treatment.

Key Considerations

Some key considerations in the treatment of syphilis include:

  • The importance of prompt treatment to prevent long-term complications [ 3 ]
  • The need for careful monitoring and follow-up care to ensure that the infection is fully cleared [ 6 ]
  • The potential for alternative treatments to be used in cases where penicillin is not suitable [ 4, 5,7 ]

References

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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