The supply interruption is the result of a combination of factors, including significant increases in demand, an increase in syphilis infection rates, as well as competitive shortages.
Pfizer notified the FDA and its customers that it will soon have limited supply on certain Bicillin formulations. Select formulations of Bicillin L-A (penicillin G benzathine) and BicillinC-R (penicillin G benzathine and penicillin G procaine) prefilled syringes are expected to be in limited supply and out-of-stock by the end of the second quarter, Pfizer said.
The supply interruption is the result of “a complex combination of factors, including significant increases in demand, an increase in syphilis infection rates, as well as competitive shortages,” Pfizer said in the letter. Syphilis infections are on the rise and pregnant women who contract the disease are at risk of the fetus dying without treatment. Syphilis rates surged 32% between 2020 and 2021, according to CDC’s most recent data. Cases of congenital syphilis also surged by an 32% and resulted in 220 stillbirths and infant deaths, the agency said.
“The U.S. sexually transmitted infection epidemic shows no signs of slowing. The reasons for the ongoing increases are multifaceted – and so are the solutions. It will take many of us working together to effectively use new and existing tools, to increase access to quality sexual healthcare services for more people, and to encourage ongoing innovation and prioritization of STI prevention and treatment in this country,” Leandro Mena, M.D., MPH, director of CDC’s Division of STD Prevention, said on the CDC’s site.
The increased demand for Bicillin came about not long after the amoxicillin shortage, which began last fall. The amoxicillin shortages were a result of increases in respiratory syncytial virus (RSV), flu, and strep cases, as well as COVID-19 infections. The FDA officially listed amoxicillin oral powder for suspension in shortage on its website in early November and healthcare facilities unable to obtain amoxicillin switched to certain formulations of Bicillin for pediatric use. Pfizer is the only Bicillin manufacturer in the United States.
To address the shortage of Bicillin, Pfizer is prioritizing two formulations— Bicillin L-A 1.2 million units/2 mL and 2.4 million units/4 mL — for the treatment of syphilis and deprioritizing other Bicillin presentations where there are other options for patients, a spokesperson told Formulary Watch.
Supply of amoxicillin — the preferred treatment for pediatric infections such as RSV — is now available from several manufacturers even though it is still listed on FDA’s Drug Shortages. Healthcare facilities, as a result, are expected to decrease their use of Bicillin formulations specifically for pediatric use.
“Overall, I think it’s a good move if discontinuing the little-used products lets them focus on Bicillin L-A, which is the only product you can use for pregnant patients with syphilis,” Erin R. Fox, Pharm.D., MHA, associate chief pharmacy officer, Shared Services, at the University of Utah Health, and adjunct professor at the University of Utah College of Pharmacy, told Formulary Watch. “These products are frequently in short supply. I’m hopeful this action will prevent a complete stockout of the Bicillin L-A.”
Pfizer does not expect full recovery of Bicillin L-A and Bicillin C-R until the third quarter of 2024.