After having been diagnosed with syphilis, treatment for syphilis cure has to be initiated and the full course of antibiotic therapy should be taken.

Syphilis can be cured with full treatment. Any halfway treatment is inviting syphilis complications, which in years to come can affect the heart and the brain. This is one of those sexually transmitted diseases (STDs) that have long-term and dangerous complications. Treatment, therefore, has to be complete.

These damages to the major organs of the body, which develop during the tertiary stage of syphilis are irreversible. Hence the importance of taking complete treatment as advised by your physician is necessary.

You can take the treatment at your general practitioner or any hospital on an OPD basis (without getting admitted).

Antibiotics for syphilis treatment

When diagnosed and treated in its early stages, syphilis can be cured easily. The preferred drug of choice at all stages is penicillin, an antibiotic that can kill the organism that causes syphilis.

If you’re allergic to penicillin, your doctor may prescribe another antibiotic or may recommend penicillin desensitization. Desensitization is a process of giving medication in a controlled and gradual manner so that the person is able to tolerate it temporarily without an allergic reaction.


To cure syphilis, treatment primarily consists of antibiotics. The antibiotic of choice is benzathine penicillin G in a single intramuscular dose if the infection is less than one year old. If you are allergic to penicillin, your doctor will use other antibiotics. Penicillin is also the treatment of choice for congenital syphilis.

Doses of penicillin stage wise

  • Primary and secondary syphilis: Benzathine penicillin G, 2.4 million units in a single intramuscular (IM) dose
  • Early latent syphilis: Benzathine penicillin G, 2.4 million units in a single intramuscular dose
  • Late latent syphilis or tertiary syphilis: Benzathine penicillin G, 2.4 million units IM three doses at one weekly interval can cure syphilis of this late stage. However, penicillin cannot reverse any organ damage that has been caused by syphilis.


In case of penicillin sensitivity, other antibiotics are used. For primary and secondary syphilis, other antibiotics that can be given are Azithromycin, a derivative of erythromycin, in a single dose.

A single, 2 g dose of oral Azithromycin is as effective as intramuscular benzathine penicillin G for the treatment of early syphilis, regardless of HIV status.


Amoxycillin is a safe and effective oral agent for the treatment of all stages of syphilis in men. In primary, secondary, early latent, late latent, and latent syphilis, 1.5 g/day amoxicillin without probenecid is effective in patients with and without HIV.

The combination of high-dose oral amoxicillin 3 g with 750 mg probenecid is highly effective and tolerable for the treatment of syphilis in patients with or without HIV infection.

Researchers recommend for patients with early syphilis, 2 weeks of treatment with the above-mentioned dose.

For patients with late latent and syphilis of unknown duration, they recommend 4 weeks of therapy with the same dose.

Doxycyclin and Tetracycline

Oral Doxycycline (100 mg 2 times/day for 14 days) and oral tetracycline (500 mg orally 4 times/day for 14 days) can be effective.

Doxycyclin and tetracycline can also be given but there is a possibility of drug resistance. Additionally, they are also contraindicated in pregnancy.

Treatment of neurosyphilis

According to NIH,

“According to international guidelines, aqueous crystalline penicillin is the first‐line treatment for neurosyphilis, while procaine penicillin plus probenecid, amoxicillin, ceftriaxone, and doxycycline could be used as alternative regimes when parenteral administration is not feasible” 

Neurosyphilis is treated with intravenous crystalline penicillin administered in doses of 24 million units for 10 to 14 days.

In case of penicillin allergy, penicillin desensitization can be done. Alternately, a third-generation antibiotic, ceftriaxone, can be used in a dose of 2 g daily either IM or IV for 10 days. It is also effective for treating primary and secondary syphilis.

Tetracycline or doxycycline can also be used but require a longer duration of treatment.

Treatment of syphilis in pregnancy

Syphilis in pregnancy continues to be a worldwide issue. In the United States, the incidence of congenital syphilis continues to increase rapidly with the highest number of cases reported in 2017.

Pregnant women are treated with penicillin on an appropriate dose for their stage of infection. Parenteral (IM or IV) penicillin G is the only drug of choice with reported safety and efficacy for both mother and fetus.

Penicillin, therefore becomes the drug of choice in pregnancy and should be used. It is the only known effective antimicrobial for treating the infection in the fetus and preventing congenital syphilis. Pregnant women can undergo a desensitization process, if sensitive to penicillin.

The current standard of the treatment of syphilis acquired during pregnancy is benzathine penicillin G in a single intramuscular injection of 2.4 million units. The success rate of this therapy is 98.2% in the prevention of congenital syphilis

Azithromycin can also be used but should be reserved as the second line of treatment. Even if the pregnant woman is treated, the newborn child must be treated with antibiotics.

During and after syphilis treatment

  • All sexual partners of the infected person must also be tested and treated.
  • The patient should avoid sexual contact with any other person until his doctor gives him the go-ahead. This could be 14 days after starting the treatment with intramuscular penicillin.
  • After a penicillin shot, the patient must stay in the clinic for 15 minutes to wait out for an anaphylactic reaction to the penicillin injection, if any.

Follow-Up testing after syphilis treatment

The CDC (Center for Disease Control) lays out the following guidelines for follow-up after treatment

Primary, secondary, early latent syphilis:

  • HIV-negative clients: Repeat RPR test at 6 and 12 months post-treatment and every 6 months for 24 months
  • HIV-positive clients: Repeat RPR at 3, 6, 9, and 12 months post-treatment and every 3 months for 24 months
  • For clients with incomplete or interrupted treatment: Repeat RPR and monitor as per physician/NP recommendations.

Syphilis can be cured but if treatment is taken too late, there may be irreversible damage to the heart, eyes, brain, and other organs. Preventing syphilis has never been so crucial.