Provider Briefing: Carbidopa/Levodopa Supply in 2026

Carbidopa/Levodopa remains the gold standard for the pharmacologic management of Parkinson's disease. Yet ongoing supply disruptions — particularly affecting extended-release and orally disintegrating formulations — continue to create challenges for providers and their patients.

This article provides a concise, clinically oriented overview of the current shortage landscape, its prescribing implications, and actionable strategies to support patient access to Carbidopa/Levodopa in 2026.

Shortage Timeline and Current Status

Intermittent shortages of Carbidopa/Levodopa have been reported to the ASHP and FDA since the early 2010s, but the situation has intensified in recent years due to manufacturer consolidation and product discontinuations:

• Accord Healthcare discontinued Carbidopa/Levodopa 25/100 mg extended-release tablets. Only the 50/200 mg ER strength remains available from Accord.
• Sun Pharma discontinued Carbidopa/Levodopa 25/250 mg orally disintegrating tablets (NDC 47335-0188-88).
• Immediate-release tablets remain available from multiple generic manufacturers (Teva, Amneal, Sun, and others), though localized shortages persist.
• Brand products — Rytary (extended-release capsules), Crexont (extended-release capsules, approved 2024), and Duopa (enteral suspension) — are not in shortage but present cost and access barriers.

The ASHP continues to list Carbidopa/Levodopa extended-release tablets and orally disintegrating tablets on its active drug shortage list. Providers should monitor this resource for updates.

Prescribing Implications

The formulation-specific nature of this shortage requires thoughtful prescribing adjustments:

ER-to-IR Conversion

For patients currently on Carbidopa/Levodopa extended-release who cannot obtain their usual formulation, conversion to immediate-release tablets is the most common approach. Key considerations:

• ER tablets have approximately 70-75% bioavailability relative to IR. When converting, total daily Levodopa dose may need to increase by approximately 25-30%.
• IR tablets require more frequent dosing — typically every 3-4 hours vs. every 6-8 hours for ER.
• Patients should be counseled that the transition may initially result in more motor fluctuations until the optimal IR schedule is established.

Formulation Alternatives

• Rytary — Extended-release capsules containing both immediate-release and delayed-release beads. Available in multiple strengths. Conversion from Sinemet IR or CR is not 1:1; follow manufacturer dosing tables. Typically requires prior authorization.
• Crexont — Approved in 2024, this extended-release capsule offers a pharmacokinetic profile with both immediate and sustained-release components. Conversion from Rytary is approximately 1:1 based on Levodopa content. May offer longer dosing intervals.
• Stalevo (Carbidopa/Levodopa/Entacapone) — Available in multiple strengths. Adding Entacapone extends Levodopa's duration and may be particularly useful for patients experiencing wearing-off phenomena. Levodopa dose reduction of 10-30% may be necessary when adding Entacapone.
• Duopa — Enteral suspension delivered via percutaneous endoscopic gastrojejunostomy (PEG-J). Reserved for advanced PD patients with severe motor fluctuations. Requires specialty referral and support.

Adjunctive Therapy Considerations

When Carbidopa/Levodopa supply is limited, adjunctive medications can help maximize the efficacy of available doses:

• Entacapone — COMT inhibitor that extends Levodopa's half-life
• Rasagiline or Safinamide — MAO-B inhibitors that reduce dopamine degradation
• Dopamine agonists (Pramipexole, Ropinirole) — Can supplement or partially replace Levodopa therapy, though with increased risk of impulse control disorders and somnolence in older patients

For detailed alternative medication information, see our patient-facing guide on alternatives to Carbidopa/Levodopa.

The Availability Picture: What's in Stock

Provider awareness of real-time pharmacy inventory can directly improve patient outcomes. Key data points:

• Generic IR tablets (all strengths) — Generally available from multiple manufacturers. Most accessible formulation.
• Generic ER tablets — Limited supply; 25/100 mg ER discontinued by Accord. 50/200 mg ER available from Accord and potentially other manufacturers.
• ODT tablets — Reduced availability following Sun Pharma discontinuation. Limited manufacturer base.
• Rytary, Crexont — Available but not typically stocked at retail pharmacies. May require specialty pharmacy channels or direct ordering.

Providers can direct patients to Medfinder for Providers to check real-time pharmacy stock in their area before writing a prescription for a specific formulation.

Cost and Access Considerations

Understanding the cost landscape helps inform prescribing decisions:

• Generic IR tablets: $8-$17 for 30 tablets (cash price); typically $0-$15 with insurance (Tier 1)
• Generic ER tablets: $12-$40 for 30-100 tablets (cash price)
• Rytary: $322-$403 for 100 capsules. Often requires prior authorization; Amneal offers a savings card for commercially insured patients.
• Crexont: Brand pricing; manufacturer savings program available for eligible patients
• Duopa: Specialty pricing; AbbVie offers patient support programs

The "eight tablet daily limit" continues to be an access barrier. Providers who need to prescribe more than 8 tablets daily may need to submit a prior authorization with clinical justification. Documentation of disease severity and clinical need typically supports approval.

Tools and Resources for Providers

• Medfinder for Providers — Real-time pharmacy stock search. Direct patients here to find Carbidopa/Levodopa availability in their area.
• ASHP Drug Shortage Resource Center — Tracks shortage status, affected NDCs, and estimated resolution timelines
• Parkinson's Foundation Helpline (1-800-4PD-INFO) — Can assist patients with medication access challenges
• NeedyMeds and RxAssist — Patient assistance program databases for uninsured or underinsured patients

For a practical workflow guide, see our article on how to help your patients find Carbidopa/Levodopa in stock.

Looking Ahead

The structural issues driving Carbidopa/Levodopa shortages — manufacturer consolidation, thin generic margins, and growing PD prevalence — are unlikely to resolve quickly. Providers should anticipate continued intermittent supply disruptions for ER and ODT formulations.

Proactive strategies include:

• Defaulting to IR formulations when clinically appropriate, given their more stable supply
• Maintaining familiarity with ER-to-IR conversion protocols
• Discussing contingency plans with patients before shortages affect them
• Monitoring ASHP and FDA shortage databases regularly
• Considering newer formulations (Crexont) when ER tablets are unavailable and the patient's insurance will cover them

Final Thoughts

Carbidopa/Levodopa shortages are a patient safety concern. Abrupt discontinuation can precipitate neuroleptic malignant syndrome-like reactions, and even dose reductions can significantly impact quality of life for Parkinson's patients. Providers play a critical role in anticipating supply issues, counseling patients on contingency plans, and leveraging available tools to maintain treatment continuity.

Direct your patients to Medfinder for Providers for pharmacy stock information, and stay current with the latest shortage updates.

For cost-saving strategies to share with patients, see our guides on saving money on Carbidopa/Levodopa and the provider's guide to helping patients save.