Your Patients Are Struggling to Find Ethosuximide—Here's How to Help

As a prescriber, you've likely received calls from patients or their parents asking for help locating Ethosuximide. This first-line absence seizure medication is highly effective but notoriously difficult to find at retail pharmacies. While there is no formal shortage in 2026, the practical reality is that many patients face repeated stockouts and delays when trying to fill their prescriptions.

This guide provides a structured, five-step approach you can integrate into your clinical workflow to help patients maintain uninterrupted access to Ethosuximide.

Current Availability: What You Need to Know

Ethosuximide is available in two formulations:

• 250 mg capsules (generic, multiple manufacturers)
• 250 mg/5 mL oral solution (brand Zarontin by Pfizer, and generic)

Neither formulation is currently on the FDA or ASHP shortage lists. However, the following market conditions create functional availability gaps:

• Very small patient population (absence epilepsy primarily affects children)
• Limited number of generic manufacturers
• Low dispensing volume at most retail pharmacies, leading to minimal or no stocking
• Wholesaler allocation practices that favor high-volume accounts

For the broader shortage context, see our companion briefing: Ethosuximide Shortage: What Providers Need to Know in 2026.

Why Patients Can't Find Ethosuximide

Understanding the patient experience helps frame your response:

• Chain pharmacies: CVS, Walgreens, and similar chains stock based on dispensing algorithms. If a store fills fewer than 1–2 Ethosuximide prescriptions per month, it likely won't maintain stock.
• Special-order delays: Even when a pharmacy agrees to order Ethosuximide, delivery can take 2–5 business days—or longer if the wholesaler is also out.
• Rural and underserved areas: Patients in areas with fewer pharmacy options face compounded difficulty.
• Formulation confusion: Some prescriptions specify capsules when only the solution is available locally, or vice versa. A formulation-locked prescription can prevent dispensing.

What Providers Can Do: 5 Actionable Steps

Step 1: Write Formulation-Flexible Prescriptions

When clinically appropriate, write prescriptions that allow pharmacist discretion between the 250 mg capsules and the 250 mg/5 mL oral solution. This doubles the chance that a pharmacy can fill the prescription from existing stock. Note on the prescription: "May dispense capsules or oral solution per patient preference."

Step 2: Direct Patients to Medfinder

Medfinder provides real-time pharmacy availability data that patients can use to locate Ethosuximide in stock near them. Consider adding Medfinder to your practice's patient resource list or post-visit handouts. This saves your staff from fielding repeated "where can I find my medication?" calls.

Step 3: Build a Pharmacy Network

Identify 2–3 pharmacies in your area that reliably stock or can quickly obtain Ethosuximide. Good candidates include:

• Independent pharmacies that serve neurology patients
• Hospital outpatient pharmacies associated with epilepsy centers
• Specialty pharmacies focused on neurology or pediatric medications
• Mail-order pharmacies with large central warehouses

Maintain a list of these pharmacies and share it with patients at the point of prescribing. Update the list quarterly to ensure accuracy.

Step 4: Implement Proactive Refill Reminders

Encourage patients (or their parents) to request refills 7–14 days before their supply runs out. This buffer gives pharmacies time to order Ethosuximide if it's not in stock. Consider:

• Setting up EHR-based refill reminders
• Discussing refill timing at every visit
• Having your medical assistant or nurse include refill planning in pre-visit calls

Step 5: Document a Backup Plan

For every Ethosuximide patient, document a medication backup plan in the chart. This should include:

• The preferred alternative medication (typically Valproic Acid or Lamotrigine)
• The transition protocol (dosing, titration schedule, monitoring plan)
• When to initiate the backup (e.g., "if unable to fill Ethosuximide within 5 days")
• A plan to return to Ethosuximide when supply is restored

Having this documented means that if a patient calls in crisis, any covering provider can act quickly.

Alternative Medications to Consider

When Ethosuximide is unavailable for an extended period, consider these alternatives:

• Valproic Acid (Depakote): Equivalent efficacy (58% seizure freedom). Widely available. Greater side effect burden. Avoid in women of childbearing potential.
• Lamotrigine (Lamictal): Lower efficacy (21% seizure freedom) but better tolerability. Preferred for women of childbearing age. Requires 6–8 week titration.
• Clobazam (Onfi): Adjunctive therapy option. Moderate evidence for certain absence syndromes. Risk of tolerance.

For a patient-facing comparison, share: Alternatives to Ethosuximide.

Workflow Tips for Your Practice

Create a Niche Medication Protocol

Ethosuximide isn't the only hard-to-find medication your patients may take. Consider developing a general protocol for niche medications that includes:

• A patient handout explaining how to use Medfinder
• A list of recommended pharmacies for hard-to-find medications
• Standard documentation templates for medication backup plans
• A process for handling urgent "can't find my medication" calls

Leverage Your EHR

Add alerts or reminders for Ethosuximide patients flagging potential availability issues. This can prompt proactive conversations at each visit rather than reactive scrambling when a patient runs out.

Connect Patients With Financial Resources

Cost can compound availability challenges. Ensure your patients know about:

• Pfizer RxPathways: Co-pay assistance and patient assistance program for Zarontin (1-844-989-4366)
• Discount cards: GoodRx ($32) and SingleCare ($36) for generic Ethosuximide
• NeedyMeds and RxAssist: Databases of patient assistance programs

For a complete cost guide, see How to Help Patients Save Money on Ethosuximide.

Final Thoughts

Ethosuximide availability challenges are unlikely to resolve quickly given the structural market factors at play. But with proactive planning, flexible prescribing, and the right tools, you can significantly reduce the burden on your patients and your practice.

Start by directing your patients to Medfinder, building a local pharmacy network, and documenting backup plans. These small steps can prevent the stressful, last-minute scrambles that no patient—or provider—should have to deal with.

For additional context, read our provider shortage briefing: Ethosuximide Shortage: What Providers Need to Know in 2026.