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

Fosfomycin (Monurol; fosfomycin tromethamine) continues to be a widely recommended first-line agent for uncomplicated urinary tract infections (UTIs) per IDSA guidelines. However, prescribers are increasingly hearing from patients who cannot fill the prescription at their preferred pharmacy. This guide summarizes the current supply situation, provides evidence-based alternatives, and offers practical tools to help your patients access treatment.

Current Supply Status: National vs. Local Availability

As of 2026, oral fosfomycin tromethamine is NOT listed in the FDA Drug Shortage Database as a national shortage. At the manufacturer and distributor levels, overall supply is considered adequate. Generic fosfomycin tromethamine is now FDA-approved and commercially available, complementing the brand Monurol.

However, individual retail pharmacies frequently carry low stock quantities — often fewer than 10 packets on hand — due to fosfomycin's single-dose nature and the resulting slow per-unit inventory turnover. A handful of prescriptions can deplete a pharmacy's entire supply within days. These are localized gaps, not a systemic shortage, but they generate significant patient friction.

The IV Formulation: Contepo (Fosfomycin for Injection)

In November 2025, the FDA approved intravenous fosfomycin (Contepo; Meitheal Pharmaceuticals) for adults with complicated UTIs (cUTIs) including acute pyelonephritis caused by susceptible E. coli and Klebsiella pneumoniae. This approval was supported by the phase 2/3 ZEUS trial, which demonstrated non-inferiority to piperacillin-tazobactam with an overall success rate of 63.5% versus 55.6%. This hospital-administered IV product is separate from the retail oral supply chain and does not affect outpatient availability.

Contepo is relevant for inpatient infectious disease and hospitalist providers managing resistant cUTIs, but does not alter the ambulatory prescribing landscape for oral fosfomycin.

When to Prescribe Fosfomycin: Clinical Indications and Stewardship

Oral fosfomycin (3g single dose) is FDA-approved for uncomplicated UTI (acute cystitis) in women caused by susceptible E. coli and E. faecalis. Key prescribing considerations include:

First-line preference: Particularly valuable in patients with known sulfa allergy (ruling out TMP-SMX), penicillin allergy, renal impairment that contraindicates nitrofurantoin, or documented resistance to other first-line agents.

MDR organisms: Fosfomycin retains activity against many ESBL-producing E. coli and other multidrug-resistant pathogens. Susceptibility testing should be specifically requested, as many laboratory panels do not include fosfomycin as a default.

Pregnancy: IDSA guidelines list fosfomycin as an acceptable option for UTIs during pregnancy. The oral bioavailability is 37%, concentrating in the urine.

NOT for pyelonephritis: Oral fosfomycin does not achieve adequate serum concentrations for upper tract infections. Reserve pyelonephritis treatment for fluoroquinolones (where susceptible) or IV agents.

Evidence-Based Alternatives When Fosfomycin Is Unavailable

IDSA 2011 guidelines (the most recent comprehensive UTI guidelines) designate three first-line agents for uncomplicated cystitis in women:

Nitrofurantoin macrocrystals/monohydrate (Macrobid): 100 mg BID × 5 days. Bacterial eradication rates consistently above 90% for E. coli. Avoid if CrCl < 30 mL/min.

TMP-SMX (Bactrim DS): 160/800 mg BID × 3 days. Appropriate when local resistance rates <20%. Not for sulfa allergy or near delivery in pregnancy.

Fosfomycin: 3g oral single dose. The drug in question; see alternatives above when unavailable.

Second-line alternatives include cephalexin 500 mg BID × 7 days. Fluoroquinolones should be reserved for complicated UTIs or culture-directed therapy due to resistance concerns and FDA safety warnings.

Practical Steps for Providers: Reducing Patient Burden

Specify generic substitution acceptable: Write "fosfomycin tromethamine 3g" and indicate generic substitution is acceptable, since some pharmacies stock only generic and not brand Monurol.

Send an alternate Rx concurrently: Consider sending a nitrofurantoin or TMP-SMX prescription alongside fosfomycin with instructions to fill only one, so the patient doesn't need to call back if fosfomycin is unavailable.

Direct patients to medfinder: medfinder for Providers (medfinder.com/providers) is a tool that contacts pharmacies near your patient to identify which ones have the medication in stock, eliminating the need for patients to make multiple calls.

Drug Interactions and Prescribing Alerts

Metoclopramide: Reduces fosfomycin absorption by increasing GI motility. Separate dosing or use an alternative antibiotic if metoclopramide is being used.

Live bacterial vaccines: Contraindicated concurrently with fosfomycin (BCG, cholera, typhoid). Complete antibiotic therapy before vaccine administration.

QTc prolongation (IV Contepo only): The IV formulation has interactions with QTc-prolonging agents (amiodarone, azithromycin, etc.). This is not a concern for the standard oral dose.

For a full provider guide on helping your patients locate fosfomycin, see our resource: How to Help Your Patients Find Fosfomycin In Stock. You can also enroll your practice at medfinder.com/providers