Lentocilin Shortage: What Providers and Prescribers Need to Know in 2026

The shortage of penicillin G benzathine — including both Bicillin L-A and its imported equivalent Lentocilin — continues to pose significant clinical challenges through 2026. With Pfizer's Bicillin L-A recovery now projected for Q4 2027, and Lentocilin's supply remaining intermittent, providers need a clear picture of the current situation, clinical prescribing guidance, and how to help their patients navigate access issues. This article provides a comprehensive briefing.

Current Supply Status (As of Mid-2026)

Key supply facts providers need to know:

Bicillin L-A (Pfizer/King Pharmaceuticals): In shortage since mid-2023. July 2025 voluntary recall of 1.2 MU and 2.4 MU prefilled syringes for particulates. Next delivery of 1.2/2.4 MU PFS extended to October 2026; full recovery projected Q4 2027. Direct physician medical request for congenital syphilis prevention: PISupplyContinuity@pfizer.com

Lentocilin (Laboratórios Atral S.A., Portugal): Imported under FDA enforcement discretion since July 2024; re-authorized March 6, 2026. Distributed in the U.S. by TopRx (800-542-8677; STDmeds@toprx.com) and through Cost Plus Drug Company marketplace. Supply is intermittent — order early and maintain backup supply where possible.

Extencilline: No longer available for distribution as of January 5, 2026. Lentocilin is the only currently available imported alternative.

Critical Clinical Differences: Lentocilin vs. Bicillin L-A

Lentocilin contains the same active ingredient (penicillin G benzathine) as Bicillin L-A, but there are important formulation differences your clinical staff must be aware of:

Formulation: Lentocilin is a powder that requires reconstitution with a provided 4 mL lidocaine 1.5% diluent. Bicillin L-A comes as a prefilled syringe. Train staff on proper reconstitution technique before first use.

Lidocaine content: The diluent for Lentocilin contains lidocaine 1.5% (60 mg per vial). Bicillin L-A does not contain lidocaine. Screen patients for lidocaine/amide-type local anesthetic hypersensitivity. Patients with cardiac dysfunction, hepatic or renal impairment require caution.

Volume: Reconstituted Lentocilin 1,200,000 units = 4 mL total volume (vs. 2 mL for Bicillin L-A 1,200,000 units). For 2,400,000 unit doses, Lentocilin requires two separate injection sites.

Soy phospholipids: Lentocilin contains soy phospholipids. Screen patients for soy allergy — reactions including anaphylaxis have been reported.

No FDA boxed warning on carton: Lentocilin's carton does not carry the Bicillin L-A boxed warning ("Fatal if given by other routes"), but the prescribing information clearly states it must only be given by deep intramuscular injection. Refer staff to the Bicillin L-A boxed warning for safety guidance.

Barcode scanning: Lentocilin is not registered in the U.S. GS1 barcode system. Manually enter product information into pharmacy systems; do not rely on barcode scanning alone.

Reconstitution and Administration Protocol

Lentocilin must be prepared and administered with rigorous technique. Key steps:

Draw up 4 mL of lidocaine diluent using an 18-gauge filter needle (or blunt needle per institutional protocol).

Disinfect rubber stopper of powder vial with alcohol. Insert needle and inject diluent toward the side of the vial — do not inject directly into the powder.

Rotate vial tightly between hands for ~20-60 seconds to homogenize. Do not shake.

Transfer suspension immediately to a syringe. Administer as soon as possible after reconstitution — do not store.

Administer by DEEP INTRAMUSCULAR INJECTION ONLY into the upper outer quadrant of the buttock (adults) or midlateral thigh (children/infants). Use minimum 18-gauge needle. Aspirate before injecting — if blood appears, withdraw and select a new site.

CRITICAL: Never administer Lentocilin intravenously, intraarterially, or subcutaneously. Inadvertent IV administration has been associated with cardiorespiratory arrest and death. Always have epinephrine and emergency equipment available when administering penicillin.

Patient Prioritization Guidance

When supply is limited, the CDC recommends prioritizing penicillin G benzathine products in the following order:

Pregnant patients with syphilis (highest priority): Penicillin is the only recommended treatment; no acceptable alternative in pregnancy.

Neonates and infants with suspected or confirmed congenital syphilis

Patients contraindicated for all alternatives: Including patients with documented doxycycline allergy or inability to adhere to oral therapy

Patients already on a multi-dose benzathine penicillin G course: Complete initiated regimens before starting new patients

Patients on rheumatic fever prophylaxis — consider oral Penicillin V as an interim alternative if supply is critically low

Alternative Regimens When Lentocilin Is Unavailable

Early syphilis (non-pregnant): Doxycycline 100 mg PO BID × 14 days

Late latent or unknown duration (non-pregnant): Doxycycline 100 mg PO BID × 28 days

Primary/secondary syphilis (limited data): Ceftriaxone 1–2 g IM or IV daily × 10–14 days (use with shared decision-making and close follow-up)

Group A strep / strep pharyngitis: Use oral amoxicillin 500 mg BID × 10 days or Penicillin VK — conserve injectable supply for syphilis patients

Rheumatic fever prophylaxis: Oral Penicillin V 250 mg PO BID; sulfadiazine for penicillin-allergic patients

How to Help Your Patients Access Lentocilin

Direct your patients to medfinder for providers — a service that helps patients locate pharmacies and clinics that have their medication in stock. For patients unable to locate Lentocilin, refer them to your local health department, which often maintains emergency supplies. For congenital syphilis cases, contact Pfizer's medical request line directly: PISupplyContinuity@pfizer.com.

Reporting Adverse Events

Report adverse events associated with Lentocilin to Mark Cuban Cost Plus Drug Company at 682-428-8081 or dtc_quality@costplusdrugs.com, and to the FDA MedWatch program at 1-800-FDA-1088. Also notify your state health department of any shortage or low inventory so the CDC can continue monitoring availability.