There is one drug approved in the United States for treating syphilis during pregnancy, one company makes it, and there is no substitute that prevents a baby from being born infected. That combination is now a supply problem that runs into late 2027.
King Pharmaceuticals, a Pfizer subsidiary, has extended the next delivery of 1.2 million-unit and 2.4 million-unit prefilled syringes of Bicillin L-A to October 2026, and pushed the anticipated recovery date to the fourth quarter of 2027, according to CDC. State health departments have been issuing rolling provider advisories ever since, including a Minnesota Department of Health update in July and a Maine CDC advisory in June.
The household consequence is narrow but severe. A pregnant patient who tests positive for syphilis needs benzathine penicillin G on a specific schedule, and treatment that comes too late in pregnancy does not reliably protect the fetus.
Why There Is No Backup Drug
For most infections, a shortage means switching antibiotics. Syphilis in pregnancy does not work that way.
Maine CDC describes Bicillin L-A as the only U.S.-approved drug "recommended for treatment of syphilis in pregnancy and preventing congenital syphilis." Doxycycline, the standard alternative for non-pregnant adults, is contraindicated in pregnancy and has not been shown to prevent fetal infection. Bicillin C-R, which contains a different penicillin combination, is not an alternative for syphilis at all.
Patients with a documented penicillin allergy are not switched to something else either. The standard of care is desensitization followed by penicillin, which requires a clinical setting equipped to do it.
CDC has therefore asked jurisdictions to preserve benzathine penicillin G for pregnant patients, and to use doxycycline for non-pregnant adults specifically to protect that supply. FDA has authorized temporary importation of Lentocilin to help fill the gap. A second imported product, Extencilline, stopped being available for distribution in January.
How the Shortage Started
The shortage predates 2026 but worsened after Pfizer's voluntary recall in July 2025 of certain lots of penicillin G benzathine injectable suspension for particulate matter contamination. CDC said at the time it was not aware of adverse events tied to that issue.
The timeline since has moved repeatedly. Earlier state notices anticipated deliveries in July 2026 and recovery in the third or fourth quarter of 2026. The current guidance from the manufacturer places the next wholesaler delivery in October 2026 and full recovery a full year later. California's health department has said the pediatric 600,000-unit prefilled syringes, used to treat infants, are not expected until December 2026.
Local health departments have been tracking each revision. San Diego County issued its fifth advisory update on the shortage in February, and New York City's health department issued its own advisory in April.
What Is Happening to Congenital Syphilis at the Same Time
The supply problem is arriving against a rising baseline.
Nearly 4,000 cases of congenital syphilis were reported in 2024, a 12th consecutive annual increase, according to CDC's provisional STI surveillance. That is up nearly 700 percent from 2015, when 495 cases were reported. The rate of increase slowed sharply in 2024, which officials called encouraging, but the absolute number did not fall.
The maternal side of the equation is still climbing. A National Center for Health Statistics report found the maternal syphilis rate rose 28 percent between 2022 and 2024, from 280.4 to 357.9 per 100,000 births, with a 52 percent increase among American Indian and Alaska Native mothers and a 31 percent increase among Hispanic mothers.
Earlier CDC analysis found that missing or delayed testing and inadequate treatment during pregnancy accounted for roughly 90 percent of congenital syphilis cases. In other words, the bottleneck has historically been access and timing rather than the drug itself. A supply constraint stacks a second bottleneck on top of the first.
Who Carries the Most Risk
The people most exposed are pregnant patients who enter prenatal care late or not at all, patients in rural areas where the nearest clinic stocking benzathine penicillin G may be a long drive, and patients who rely on public health clinics that receive allocated rather than open supply.
Congenital syphilis can cause stillbirth, miscarriage and neonatal death. Infants who survive without adequate treatment can develop blindness, deafness, developmental delays and bone abnormalities.
Adults on chronic benzathine penicillin injections for rheumatic fever prophylaxis are a second affected group, and clinicians have been advised to consult cardiology or infectious disease about schedule modifications rather than simply stopping.
What Patients Should Do Now
Ask about syphilis testing at the first prenatal visit and again in the third trimester, and ask for the result rather than assuming no news means negative. Many states require third-trimester and delivery testing, and requirements vary.
Anyone who tests positive during pregnancy should ask directly whether the clinic has benzathine penicillin G on hand or needs to source it, and how quickly. Treatment timing relative to delivery determines whether the fetus is protected, so a two-week delay is not a neutral scheduling issue.
Patients with a reported penicillin allergy should ask about allergy evaluation and desensitization early rather than at the point of treatment. Many reported penicillin allergies are not confirmed on testing.
If a clinic cannot obtain supply, local and state health departments maintain allocated stock for priority patients and should be contacted directly. Do not accept an oral substitute for syphilis in pregnancy without an explicit conversation about why.
What Happens Next
The next verifiable milestone is the October 2026 wholesaler delivery. Whether that arrives on schedule will determine how much longer jurisdictions ration supply, and the manufacturer's own recovery estimate has been revised more than once.
CDC continues to publish updates on availability, and FDA maintains the drug shortage listing. State health departments are the most current source for local allocation rules, since stock levels differ substantially by jurisdiction. MedicalDaily will track the October delivery and any further revision to the recovery date.
Frequently Asked Questions
What is Bicillin L-A used for? It is a long-acting injectable penicillin used to treat syphilis, and it is the only recommended treatment for syphilis during pregnancy and for preventing congenital syphilis.
How long will the shortage last? The manufacturer has extended the next delivery to October 2026 and anticipates full recovery to the fourth quarter of 2027.
Is there an alternative for pregnant patients? No equivalent substitute exists. Imported benzathine penicillin products authorized by the FDA are used where available. Doxycycline is not appropriate during pregnancy.
What if I am allergic to penicillin? The standard approach is allergy evaluation and desensitization followed by penicillin, not a different drug. Raise this early in prenatal care.
Why are newborn syphilis cases rising? Cases rose for a 12th straight year in 2024. CDC analysis has attributed most cases to missed or delayed testing and inadequate treatment during pregnancy.
Where can I get tested? Prenatal providers, local health department STI clinics, and federally qualified health centers offer testing, often at low or no cost.
Does this shortage affect strep throat treatment? Providers have been advised to use oral alternatives such as amoxicillin or penicillin V for strep throat to preserve injectable supply.
