PROMETHAZINE W/ DEXTROMETHORPHAN Drug Patent Profile

When do Promethazine W/ Dextromethorphan patents expire, and when can generic versions of Promethazine W/ Dextromethorphan launch?

Promethazine W/ Dextromethorphan is a drug marketed by Pharmobedient and is included in one NDA.

The generic ingredient in PROMETHAZINE W/ DEXTROMETHORPHAN is dextromethorphan hydrobromide; promethazine hydrochloride. There are twenty-three drug master file entries for this compound. Fourteen suppliers are listed for this compound. Additional details are available on the dextromethorphan hydrobromide; promethazine hydrochloride profile page.

Summary for PROMETHAZINE W/ DEXTROMETHORPHAN

US Patents:	0
Applicants:	1
NDAs:	1

US Patents and Regulatory Information for PROMETHAZINE W/ DEXTROMETHORPHAN

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Pharmobedient	PROMETHAZINE W/ DEXTROMETHORPHAN	dextromethorphan hydrobromide; promethazine hydrochloride	SYRUP;ORAL	088864-001	Jan 4, 1985	AA	RX	No	No

Investment Scenario and Fundamentals Analysis: Promethazine With Dextromethorphan

Last updated: April 26, 2026

Promethazine with dextromethorphan is a fixed-dose, centrally acting cough-and-allergy combination sold in multiple dosage forms in the US and other markets. Commercial fundamentals are driven by (1) baseline cough-and-cold demand, (2) formulary access at retail and payer level, (3) product-level regulatory and labeling constraints for abuse potential and pediatric use, and (4) competitive dynamics versus single-entity antitussives and newer prescription cough therapies in subsegments. For investors, the key question is not patent life alone, but whether the product remains protected by regulatory exclusivities, formulation/presentation-specific patents, and trade-channel entrenchment versus generic pressure.

What is the product and where does it sit in the market?

Composition

• Promethazine + dextromethorphan (antihistamine with antiemetic/sedating properties plus antitussive cough suppression).

Therapeutic use

• Symptomatic treatment of cough associated with colds and related upper respiratory conditions, often targeted to patients where antihistamine activity is clinically desired (symptom relief bundles).

Market structure

• Fixed-dose combinations typically face:
  • Price pressure from single-ingredient generics and multi-source combination generics.
  • Formulary scrutiny because sedating antihistamines carry safety considerations.
  • Label restrictions (pediatric and abuse-related warnings) that can reduce addressable demand.

Business implication

• The segment tends to be volume-led and net-price constrained, with value creation more dependent on distribution, compliance, and product differentiation (dosage form, strength, and packaging/patient targeting) than on large-scale innovation.

What are the likely patent and exclusivity fundamentals?

Promethazine and dextromethorphan are long-established active ingredients. The investment case for a combination product typically hinges on secondary protection (formulation, delivery system, method of use) and regulatory exclusivities tied to specific NDA/ANDA reference products and their amendments.

Patent posture (typical for legacy combinations)

• Active ingredient patents have mostly expired.
• Protection, if any, is usually presentation- and formulation-specific, or it covers:
  • Extended-release or controlled delivery if applicable (less common for standard cough syrups/tablets)
  • Manufacturing/process improvements
  • Stability and shelf-life enhancements
  • Abuse-deterrent features (only if present in the product)

Exclusivity posture (typical)

• If the product is reformulated or reintroduced via a specific regulatory pathway, exclusivities can arise around:
  • New clinical investigations for a given formulation/presentation
  • Line extensions
  • Updated labeling approvals that meet regulatory criteria

Investment lens

• For fixed-dose combinations of off-patent actives, base-case economics often assume generic competition is structurally inevitable. The correct underwriting question becomes:
  • Does the company own or control a defensible product-specific asset (formulation/presentation) that delays full generic commoditization in a major channel?

How does labeling and safety shape demand and reimbursement?

For cough-and-cold and sedating antihistamine combinations, US demand is constrained by safety and labeling requirements. These factors affect:

• Retail sales velocity (consumer confidence and prescribing behavior)
• Pharmacist and clinician discretion (patient selection)
• Payer restrictions (coverage exclusions for pediatric use, age gates, or prior authorization in some plans)

Key demand-impact mechanisms

1. Age-related restrictions
   Pediatric safety constraints typically reduce the addressable market for OTC-like products and shift more usage toward clinician-directed care where appropriate.
2. Abuse potential warnings
   Dextromethorphan has abuse-related risks; promethazine adds sedation risks. Labeling influences:
   • Sales to lower-risk populations
   • Clinician reluctance in patients with substance use history
3. Sedation and CNS risk
   Promethazine’s sedative effects can limit use in working-age populations unless clearly indicated and appropriately counseled.

Investment implication

• Sales volume depends on segments that tolerate sedation risk and have stable access to symptomatic cold remedies. That produces:
  • Seasonal demand (winter respiratory seasonality)
  • Lower premium pricing power (payers and competitors push price)

What are the competitive substitutes and how do they pressure price?

Primary substitute categories

• Single-entity dextromethorphan products (generic coverage broad)
• Non-dextromethorphan antitussives (where used in practice)
• Antihistamine-only cough/cold combinations where antihistamine sedation is preferred
• Prescription cough options in defined etiologies (not direct substitutes for routine colds, but they matter in payer behavior for chronic cough subsegments)

Competitive pressure points

• Substitution is easy for patients and physicians because:
  • Dextromethorphan generics are widely available.
  • Promethazine generics are widely available.
  • Many products have overlapping symptom claims.
• Retail channels seek lowest net cost consistent with labeled indication and patient safety.

Investment implication

• Without product-specific differentiation, the combination product tends to be priced down to near the generic basket. Investor upside is driven by:
  • Channel share gains
  • Contract manufacturing with lower COGS
  • Package-level differentiation that preserves share
  • Any ongoing lifecycle protection that delays full erosion in key strengths/pack sizes

What does the earnings model likely look like?

For legacy combination products, fundamentals usually follow a classic model:

• Revenue: driven by seasonality (cold/cough cycles), distribution reach, and share.
• COGS: tied to formulation complexity, packaging, and manufacturing scale.
• Gross margin: compressed under generic competition; can be protected by:
  • Exclusive distribution agreements
  • Brand-like channel execution even after generic entry (depends on jurisdiction and labeling status)
  • Efficient supply chain and packaging cost optimization
• Operating expense: lighter than for innovation-heavy portfolios, but compliance and pharmacovigilance remain necessary.

Baseline financial sensitivities (investment underwriting)

Driver	If it improves	If it worsens
Channel share	Higher volume offsets price erosion	Share loss accelerates margin compression
Net price	Better payer/retailer terms	Generic undercutting reduces net revenue
Seasonality	Stronger respiratory season	Dry winter reduces demand
Safety/label updates	Stable or favorable label	Restrictive warnings reduce addressable demand
Manufacturing cost	Lower COGS and shrink	Margin squeeze from supply disruptions or scale inefficiency

What are the regulatory and manufacturing risks investors should model?

Regulatory risk channels

• Label changes affecting age restrictions or safety language can reduce demand.
• Abuse-related scrutiny can trigger additional warnings or enforcement that discourages use.
• Product formulation changes required for stability or compliance can trigger reformulation costs and temporary supply disruption.

Manufacturing and supply

• Fixed-dose liquids are often sensitive to:
  • Stability and viscosity consistency
  • Packaging compatibility
  • Supply chain continuity for bulk actives and excipients

Investment implication

• The business can be robust if the company controls manufacturing scale and quality systems. It weakens if reliance on third-party manufacturing introduces variability or shortage risk during peak season.

How should investors frame the “investment scenario” for this asset class?

Base-case scenario (most likely for legacy combinations)

• Generic competition persists.
• The product remains profitable mainly through operational excellence:
  • Low COGS
  • High distribution coverage
  • Compliance and consistent supply
• Growth is modest, tied to share and seasonality, not innovation.

Upside scenario (where returns can outperform)

• The holder has presentation-level control (specific strengths, package sizes, or patient-targeted formulations) that slows price erosion.
• The company preserves channel standing via:
  • Contracts
  • Service-level reliability
  • Strong retailer relationships
• Any remaining lifecycle protection or regulatory exclusivity is sufficient to extend margin headroom in key SKUs.

Downside scenario (where returns compress)

• Rapid substitution to cheaper alternatives (single-entity generics) and intense retailer price competition.
• Label tightening further reduces eligible populations.
• Supply disruption during peak season causes lost share and higher logistics costs.

Key diligence checklist for a deal or investment decision

A high-quality underwriting packet should validate:

1. SKU-level economics
   Net price and gross margin by strength and packaging; identify which SKUs carry profitability.
2. Channel exposure
   Mix of pharmacy, mass retail, mail order, and institutional demand; contract terms and rebate structures.
3. Regulatory status by jurisdiction
   Labeling, age restrictions, and any post-market safety actions.
4. Patent and exclusivity inventory
   Confirm any remaining patents and whether they are enforced or time-barred by generic equivalents.
5. Safety and pharmacovigilance operations
   Signals, complaint rates, and corrective actions that could trigger market impact.

What are the market indicators that typically move near-term demand?

• Respiratory seasonality: winter peaks drive volume.
• Retail promotional intensity: price-led promotions can lift volume but reduce net margin.
• Substitution behavior: patients and clinicians swap to lower-cost single-entity products when available.
• Formulary updates: payer preference changes can shift volume quickly during annual cycles.
• Regulatory messaging: changes to safety perceptions for cough/cold products affect purchase patterns.

Key Takeaways

• Promethazine with dextromethorphan is a legacy fixed-dose combination where economics are typically volume and net-price driven, with limited innovation-led upside unless protected by presentation-specific assets.
• Demand is shaped by sedation risk, pediatric restrictions, and abuse-potential labeling, which constrain addressable market and affect clinician and payer behavior.
• Generic substitutes (single-entity dextromethorphan and promethazine products) create structural price pressure, making the investment case dependent on channel execution and SKU-level defensibility.
• The best underwriting focuses on net price, gross margin by SKU, channel mix, and any remaining exclusivity/presentation protection, not only headline patent dates.

FAQs

1) Is promethazine with dextromethorphan likely to face rapid generic erosion?
Yes. Both actives are widely generic, so the combination product typically competes in a multi-source environment unless the holder has presentation-specific protection and strong channel entrenchment.

2) What drives short-term revenue for this product category?
Seasonality in cough and cold demand, retailer promotion intensity, and contract pricing terms that determine net revenue during peak months.

3) How do labeling constraints impact investors?
Age restrictions and abuse- and sedation-related warnings can reduce the eligible patient pool and shift prescribing and coverage behavior, lowering volume and constraining price.

4) Where can upside come from in a legacy combination?
From SKU-level differentiation, control of key package sizes/strengths, operational cost advantages, and any remaining regulatory exclusivity or formulation-specific protection.

5) What diligence item is most likely to change the valuation?
SKU-level net price and gross margin versus the competitive basket, because those metrics determine whether the product can sustain profitability under ongoing generic substitution.

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References (APA)

1. FDA. (2016). Safety labeling changes related to codeine and tramadol products. U.S. Food and Drug Administration. https://www.fda.gov/drugs/drug-safety-and-availability
2. FDA. (2017). Press Announcements and Drug Safety Communications for dextromethorphan and cough medicines in children. U.S. Food and Drug Administration. https://www.fda.gov/news-events/press-announcements