Japan is continuing to face a shortage of penicillin, the first-choice treatment for syphilis, amid persistently high infection levels, with production halted after an equipment failure at a manufacturer’s plant not expected to resume until the latter half of next year.
The drug is also the only treatment recommended for preventing mother-to-child transmission of syphilis, prompting the Japanese Society for Sexually Transmitted Infections to urge medical professionals to prioritise its use for pregnant women.
Syphilis, a sexually transmitted infection, has been increasingly reported since around the end of the coronavirus pandemic. Cases rose from about 6,000 in 2020 to more than 13,000 in 2025.
If syphilis is transmitted to a fetus through the placenta, it can result in stillbirth or premature birth, as well as congenital syphilis, which can cause neurological and bone abnormalities in children.
Production halted after equipment failure
Pfizer’s syphilis treatment was voluntarily recalled in July 2025 after foreign matter was found in the product.
A manufacturing equipment failure occurred at the company’s plant in November that year, further affecting production.
Pfizer said it expects shipments to resume around the “latter half of next year”, citing the time required to prepare its facilities and complete regulatory checks.
The prolonged shortage has raised concerns over access to the treatment, particularly for patients who have limited alternatives.
Medical institutions urged to prioritise supplies
The Japanese Society for Sexually Transmitted Infections issued guidance to medical institutions on Aug. 24, urging them to avoid unnecessary prescriptions after assessing patients’ conditions.
It also asked pharmacies not to place large orders because of concerns over supplies.
The organisation proposed prioritising penicillin for pregnant women and patients for whom alternative drugs are not suitable.
Hiroshige Mikamo, a professor at Asahi University in Gifu Prefecture, described the guidance as “a preventive step to protect patients’ treatment opportunities”.
Mikamo, who chairs the organisation’s syphilis committee, also advised patients to continue seeking medical care despite the shortage.
