As a bacterial infection, syphilis canonlybe treated with antibacterial drugs known asantibiotics.
Penicillin G
Penicillin Gis the antibiotic of choice in almost all cases.
Penicillin G, also known asbenzylpenicillin, is used to treat many different types of bacterial infections.
Illustration by Joshua Seong. © Verywell, 2018.
It is sometimes called a “peanut butter shot” because of its thick consistency.
The drug is typically delivered by a singleintramuscular injectioninto a large muscle, usually the buttocks.
In severe cases, penicillin may be given intravenously (by injection into a vein).
Each progressive stage has different symptoms and may need to be treated differently.
Alternatives to Penicillin
Other antibiotics may be used for people with syphilis who areallergic to penicillin.
These include the antibioticsceftriaxone, doxycycline, and tetracycline.
Drug Desensitization for Penicillin
Penicillin desensitization is used to make a person less sensitive to penicillin.
It involves exposing the individual to gradually increasing doses of penicillin every 15 to 20 minutes in a hospital.
When the optimal dose is reached without triggering an allergic reaction, the treatment can begin.
There are cases where penicillin G is theonlyoption and the benefits of treatment may outweigh the risks.
This includes the treatment of congenital syphilis in which theT.
pallidumis passed from mother to child during pregnancy.
This would be the case even if the partner’ssyphilis testis negative.
If the test result is negative, no treatment is required.
If left untreated, fungating gummas become infected and lead tosepsis(blood poisoning).
Summary
Penicillin G is the mainstay of treatment for syphilis.
If penicillin G cannot be used due to a penicillin allergy, other antibiotics may be prescribed.
The sexual partners of someone with syphilis should also be treated.
A Word From Verywell
Many people with syphilis have no idea that they’ve been infected.
Because of this, the CDC recommends routine screening for people at high risk of infection or disease complications.
These include pregnant persons,men who have sex with men (MSM), andpeople with HIV.
Frequently Asked Questions
An intramuscular injection of penicillin G is the preferred treatment.
Late latent and tertiary syphilis are treated with three doses of penicillin G given at one-week intervals.
Even if there is an allergy, penicillin G is still the treatment of choice.
Your healthcare provider may do allergy testing to verify if you are at true risk.
Penicillin G is the only recommended treatment during pregnancy.
Pregnant persons who are allergic to penicillin would need to undergo penicillin desensitization in a hospital.
You would need to abstain from sex until the syphilis sores (calledchancres) are fully healed.
A four-fold decrease in antibodies after one year is considered a treatment success.
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Centers for Disease Control and Prevention.Sexually transmitted infections treatment guidelines, 2021.
Ramchandani MS, Litvack JR, Marra CM.Otosyphilis: a review of the literature.Sex Transm Dis.
2020 May;47(5):296300. doi:10.1097/OLQ.0000000000001155
Centers for Disease Control and Prevention.Primary and secondary syphilis.
Centers for Disease Control and Prevention.Syphilis during pregnancy.
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