Oseltamivir Shortage: A Clinical Update for Providers

The ongoing Oseltamivir shortage during the 2025–2026 influenza season is creating real challenges in clinical practice. As of February 2026, the ASHP lists multiple Oseltamivir formulations in shortage, and several generic manufacturers report back orders with no firm resolution dates.

This guide provides an evidence-based overview for prescribers — including shortage scope, CDC triage guidance, alternative antivirals, compounding considerations, and tools to help your patients locate available supply.

Current Shortage Scope

The ASHP drug shortage database (updated January 7, 2026) confirms active shortages across multiple Oseltamivir presentations:

• Capsules (30 mg, 45 mg, 75 mg) — back-ordered from Amneal, Alvogen, and other generics
• Oral suspension (6 mg/mL) — Teva has 60 mL bottles on back order; no estimated release date
• Brand Tamiflu — two presentations discontinued by Genentech, though some brand stock remains in the channel

The FDA has not listed Oseltamivir on its own shortage database, which may cause confusion for providers checking only the FDA site. The ASHP database is the more reliable real-time source for this shortage.

Driving Factors

The primary driver is the severity of the 2025–2026 flu season, which has produced some of the highest influenza-like illness (ILI) rates in over a decade. Contributing factors include:

• Higher-than-average influenza A (H3N2) circulation with significant morbidity
• Prescription volume exceeding seasonal manufacturing forecasts
• Limited buffer stock — generic manufacturers do not typically overproduce seasonal medications
• Oral suspension manufacturing constraints (separate production line from capsules)

CDC Interim Guidance on Prioritization

During previous Oseltamivir shortages (notably 2022–2023), the CDC issued interim guidance recommending prioritized allocation. While providers should check for updated 2026 guidance, the general framework recommends prioritizing Oseltamivir for:

1. Hospitalized patients with confirmed or suspected influenza
2. Patients with severe or progressive illness regardless of setting
3. High-risk outpatients — including adults ≥65, children <2, pregnant/postpartum women, immunocompromised patients, residents of long-term care facilities, and patients with chronic medical conditions

For otherwise healthy adults and children with uncomplicated influenza, the CDC has suggested considering alternative antivirals when Oseltamivir is unavailable.

Alternative Antivirals: Clinical Considerations

Three FDA-approved alternatives are available. Here's a clinical comparison to inform prescribing decisions:

Baloxavir Marboxil (Xofluza)

• Mechanism: Cap-dependent endonuclease inhibitor
• Dosing: Single oral dose (weight-based: 40 mg for 40–<80 kg; 80 mg for ≥80 kg)
• Approved ages: ≥5 years (treatment); ≥1 year (post-exposure prophylaxis)
• Key advantage: Single-dose adherence; different mechanism may address neuraminidase inhibitor resistance
• Key concern: Treatment-emergent resistance (I38T substitution) reported in ~10% of influenza A patients in clinical trials, though clinical significance remains debated
• Cost: ~$100–$180 brand-only; manufacturer savings card available

Zanamivir (Relenza)

• Mechanism: Inhaled neuraminidase inhibitor
• Dosing: 10 mg (2 inhalations) twice daily × 5 days via Diskhaler
• Approved ages: ≥7 years (treatment); ≥5 years (prophylaxis)
• Key advantage: Different supply chain from oral Oseltamivir; may be available when capsules are not
• Contraindication: Do not prescribe for patients with underlying airway disease (asthma, COPD) — risk of bronchospasm
• Practical note: Diskhaler technique can be challenging for some patients; ensure adequate counseling

Peramivir (Rapivab)

• Mechanism: IV neuraminidase inhibitor
• Dosing: Single 600 mg IV infusion over 15–30 minutes (adults); weight-based in pediatrics
• Approved ages: ≥6 months
• Best for: Hospitalized patients, patients unable to tolerate oral/inhaled medications
• Practical note: Requires healthcare facility administration; not stocked in most outpatient settings

Compounding Considerations

When the oral suspension is unavailable for pediatric patients, pharmacists can compound an oral suspension from Oseltamivir 75 mg capsules. The FDA has published stability data and compounding instructions. Key points:

• Compounded suspension is stable for up to 35 days when refrigerated (in Ora-Sweet SF)
• Providers should coordinate with the dispensing pharmacy to ensure compounding capability
• Document the compounding instructions on or with the prescription

Helping Patients Locate Supply

Stock availability varies significantly by pharmacy and region. To help your patients:

• Direct them to MedFinder for real-time pharmacy stock searches
• Suggest calling independent and grocery store pharmacies, which may have different wholesaler relationships
• Consider e-prescribing to multiple pharmacies if the first is out of stock (where regulations allow)
• For your practice, consider using MedFinder for Providers to streamline the process of locating in-stock pharmacies for your patients

Prescribing Tips During the Shortage

• Specify "dispense as written" carefully. If you write for brand Tamiflu, the pharmacy cannot substitute generic (and vice versa in some states). During a shortage, allowing generic substitution maximizes the chance of the patient getting filled.
• Consider Baloxavir first-line for low-risk patients. Single-dose convenience and different supply chain may improve patient access.
• Document shortage-related decisions. If deviating from your usual prescribing patterns, note the clinical rationale.
• Remind patients about the 48-hour window. Emphasize urgency — patients who can't find Oseltamivir should call back immediately for an alternative, not wait for a restock.

Resources

• ASHP Oseltamivir Shortage Detail
• CDC: Influenza Antiviral Medications — Summary for Clinicians
• MedFinder for Providers

For the patient-facing version of this article, see our Oseltamivir shortage update for patients. For guidance on helping patients save on costs, see our provider's guide to Oseltamivir cost savings.