How to Help Your Patients Find Colistin in Stock: A Provider's Guide

Helping Patients Access Colistin: A Clinical Guide

When you prescribe Colistin (Colistimethate Sodium) for a patient with a multidrug-resistant gram-negative infection, you expect the pharmacy to have it. Unfortunately, in 2026, that expectation often goes unmet. Colistin shortages have become a recurring challenge, and patients are increasingly coming back to their providers frustrated, anxious, and without their prescribed medication.

As a prescriber, you have more tools and leverage than your patients do when it comes to sourcing medications. This guide outlines practical steps you can take to help patients access Colistin, even during supply disruptions.

Current Availability

Colistimethate Sodium for injection (150 mg colistin base activity per vial) remains intermittently available in the U.S. market. Key manufacturers include Xellia Pharmaceuticals, Par Pharmaceutical, and Hikma Pharmaceuticals. Supply fluctuates on a week-to-week basis, with some hospital systems maintaining adequate stock while others experience gaps.

The root causes haven't changed: too few manufacturers, rising demand from MDR gram-negative infections, complex fermentation-based manufacturing, and minimal financial incentive for new market entrants at approximately $31-44 per vial wholesale.

For a detailed timeline and context, refer to our provider shortage briefing.

Why Patients Can't Find Colistin

Understanding your patients' perspective is important. Unlike oral medications they can pick up at a corner pharmacy, Colistin presents unique access barriers:

• Not stocked at retail pharmacies: Chain pharmacies (CVS, Walgreens, Rite Aid) don't typically carry injectable antibiotics like Colistimethate Sodium.
• Hospital pharmacy dependence: Patients transitioning from inpatient to outpatient parenteral antibiotic therapy (OPAT) often can't find a home infusion pharmacy with stock.
• No patient-facing search tools: Until recently, patients had no way to check pharmacy inventory for injectable medications. Most rely on phone calls — a time-consuming and unreliable approach.
• Insurance complexity: Colistin is typically billed under the medical benefit, not pharmacy. Patients may encounter prior authorization requirements, formulary restrictions, or high cost-sharing for outpatient infusion.

What Providers Can Do: 5 Actionable Steps

Step 1: Coordinate With Your Hospital Pharmacy Early

Don't wait until discharge to address medication access. As soon as you prescribe Colistin — especially for OPAT — loop in the hospital pharmacist to:

• Confirm current hospital stock levels
• Check availability through the institution's wholesaler and GPO contracts
• Identify backup supply channels (manufacturer direct, specialty distributors)
• Secure enough supply for the full treatment course before the patient transitions to outpatient

Step 2: Use Medfinder for Providers

Medfinder for Providers allows clinical teams to search pharmacy inventories in real time. Instead of calling pharmacies individually, you can quickly identify which locations have Colistin in stock and coordinate with them directly.

Share this tool with your case management and social work teams so they can assist with medication sourcing as part of discharge planning.

Step 3: Establish Relationships With Specialty Infusion Pharmacies

For patients on OPAT, specialty home infusion pharmacies are often better positioned than hospital outpatient pharmacies to source limited-supply injectables. Build relationships with 2-3 infusion pharmacies in your area and verify their ability to access Colistin before prescribing OPAT regimens that include it.

Some national specialty pharmacy networks include:

• BioScrip/Option Care Health
• PharMerica
• Orsini Specialty Pharmacy

Step 4: Explore Alternative Agents Proactively

When culture data suggests susceptibility to alternatives, consider whether a non-polymyxin option might serve the patient equally well:

• Polymyxin B: Closest substitute — same class, similar spectrum. May be available when Colistin is not.
• Ceftazidime-Avibactam (Avycaz): More expensive (~$500-1,000+/day) but more widely available and less nephrotoxic.
• Cefiderocol (Fetroja): Active against some Colistin-resistant organisms. ~$400-600/day.
• Amikacin or Tobramycin: Aminoglycosides with activity against some MDR gram-negatives. Established safety profiles with therapeutic drug monitoring.

For a clinical comparison, see our alternatives overview.

Step 5: Address Cost Barriers

Even when Colistin is found, cost can be a barrier — particularly for uninsured or underinsured patients. At approximately $1,306 for 30 vials without insurance, a full treatment course can be prohibitive.

Steps to mitigate cost:

• Verify insurance coverage and obtain prior authorization early in the treatment course
• Connect patients with hospital financial assistance / charity care programs
• Check NeedyMeds and RxAssist for assistance programs that may cover injectable antibiotics
• Explore discount programs — SingleCare coupons can reduce the price to approximately $207-265 for 30 vials

For detailed patient cost guidance, refer patients to: How to Save Money on Colistin.

Alternatives at a Glance

Quick reference for therapeutic interchange during Colistin shortages:

• Polymyxin B — Same class, comparable efficacy. Check local availability. Also subject to intermittent shortages.
• Ceftazidime-Avibactam — Preferred for KPC-producing CRE when susceptible. More available, less toxic, higher cost.
• Cefiderocol — Broad MDR gram-negative coverage. Newer agent with growing clinical experience.
• Meropenem-Vaborbactam (Vabomere) — Another option for certain KPC-producing infections.
• High-dose Meropenem + Colistin combination — When Colistin is available but supply is limited, combination therapy may allow dose reduction.

Workflow Tips

Integrate shortage management into your clinical workflow:

1. Check availability before prescribing: A 30-second Medfinder search can save hours of downstream frustration.
2. Include pharmacy in multidisciplinary rounds: Pharmacists can flag supply issues in real time during patient care discussions.
3. Develop institutional shortage protocols: Work with your antimicrobial stewardship team to create Colistin shortage response plans that include automatic therapeutic interchange pathways.
4. Educate case managers: Ensure discharge planning teams understand that Colistin is a high-risk medication for post-discharge access and should start sourcing early.
5. Document alternative rationale: When switching from Colistin to an alternative due to shortage, document the clinical rationale clearly for insurance and medical-legal purposes.

Final Thoughts

The Colistin shortage is a systems problem, but individual providers can make an enormous difference for their patients through proactive planning, early pharmacy engagement, and smart use of tools like Medfinder for Providers.

The patients who need Colistin are fighting life-threatening infections. They need their clinical teams fighting just as hard to get them their medication. By building shortage-resilient workflows and maintaining awareness of alternatives, you can ensure that supply constraints don't become barriers to effective treatment.

Related provider resources:

• Colistin Shortage: What Providers Need to Know in 2026
• How to Help Patients Save Money on Colistin