Imipenem/Cilastatin Shortage Update: What Patients Need to Know in 2026

If you or someone you care for needs Imipenem/Cilastatin — the powerful carbapenem antibiotic sold as Primaxin — and you're being told it's unavailable, this article is for you. We'll give you the most up-to-date picture of the shortage, explain what it means for your treatment, and outline the concrete steps you can take right now.

Current Shortage Status (2026)

As of 2026, Imipenem and Cilastatin for Injection is listed as "Currently in Shortage" in the FDA Drug Shortage Database. The ASHP (American Society of Health-System Pharmacists) also lists this drug on its active shortage tracking system. This means the shortage is federally recognized, and the FDA is actively working with manufacturers to mitigate supply disruptions — but there is no confirmed resolution date.

The shortage affects all manufacturers of the injectable formulation. Key manufacturers — Fresenius Kabi and Pfizer (Hospira) — have both faced supply constraints, Fresenius due to increased demand and Hospira due to manufacturing delays. The brand name Primaxin IV (manufactured by Merck) may have different availability than generic presentations.

A Brief History of the Imipenem/Cilastatin Shortage

This is not the first time Imipenem/Cilastatin has been in shortage. The drug has appeared on ASHP shortage lists multiple times dating back to at least 2015. The recurring nature of this shortage reflects structural vulnerabilities in the sterile injectable antibiotic market — concentrated manufacturing, thin margins, and complex production requirements that make rapid scale-up difficult.

The COVID-19 pandemic compounded these vulnerabilities, disrupting supply chains and causing demand surges for injectable antibiotics. As a result, shortages that might have been brief in previous years have stretched on much longer.

Who Does the Shortage Affect Most?

Because Imipenem/Cilastatin is given intravenously, the shortage primarily affects:

• Hospitalized patients with serious polymicrobial infections, sepsis, or intra-abdominal infections

• Patients with infections caused by drug-resistant bacteria, including ESBL-producing Enterobacteriaceae and certain Pseudomonas strains

• Immunocompromised patients (transplant recipients, cancer patients on chemotherapy) who need broad-spectrum coverage

• Post-surgical patients at risk for polymicrobial wound infections

• Patients transitioning from hospital to outpatient IV therapy (OPAT) programs

What Does the Shortage Mean for My Treatment?

If you are currently on Imipenem/Cilastatin and your hospital or infusion pharmacy is having trouble sourcing it, your medical team has several options:

1. Switch to meropenem: This is the most common approach. Meropenem has very similar clinical activity and is often more readily available. For most infections, the clinical outcome is equivalent.

2. Source from alternate supplier: Hospital pharmacies can often access Imipenem/Cilastatin from a different manufacturer or distributor than the one experiencing the shortage. Different vial strengths may be available even when the primary strength is not.

3. Extended infusion protocols: Some institutions extend the infusion time of available doses to maximize antibiotic exposure, allowing conservation of supply while maintaining therapeutic efficacy.

Will the Shortage Affect the Safety of My Treatment?

The existence of a shortage is stressful, but it does not mean your infection will go untreated. Hospital antibiotic stewardship programs and infectious disease specialists are well-versed in managing carbapenem shortages. They have established protocols to ensure patients receive clinically appropriate therapy even when the primary agent isn't available.

That said, switching antibiotics introduces additional considerations — your culture results, allergy history, and organ function all need to be rechecked before starting a new agent. This is why it's important to communicate clearly with your healthcare team about any concerns.

What Patients Should Do Right Now

• Don't stop your antibiotic course: If you are already receiving Imipenem/Cilastatin, do not stop taking it without medical supervision, even if it becomes harder to find.

• Tell your healthcare team immediately: If your pharmacy tells you they can't fill the prescription, contact your prescribing physician or hospital pharmacy right away. Don't wait.

• Use medfinder to check nearby locations: medfinder calls pharmacies and infusion centers in your area to find which ones have Imipenem/Cilastatin in stock, saving you hours of calling around.

• Ask about alternatives proactively: Discuss with your physician whether meropenem or ertapenem could be an appropriate substitute for your infection, so you have a backup plan ready if the drug becomes unavailable.

How medfinder Can Help

medfinder is a paid service that calls pharmacies and infusion centers near you to check which ones have Imipenem/Cilastatin in stock. When an antibiotic shortage is active, knowing which facility has stock in real time can be the difference between getting your treatment on schedule and facing a dangerous gap. Submit your request online, and medfinder will text you the results.

For more on what to do if you can't find this medication, see our complete guide on alternatives to Imipenem/Cilastatin.