AMOXAPINE - Generic Drug Details

What are the generic sources for amoxapine and what is the scope of patent protection?

Amoxapine is the generic ingredient in two branded drugs marketed by Chartwell Rx, Watson Labs, Watson Pharms Teva, and Lederle, and is included in seven NDAs. Additional information is available in the individual branded drug profile pages.

There are four drug master file entries for amoxapine. Two suppliers are listed for this compound.

Summary for AMOXAPINE

US Patents:	0
Tradenames:	2
Applicants:	4
NDAs:	7
Drug Master File Entries:	4
Finished Product Suppliers / Packagers:	2
Raw Ingredient (Bulk) Api Vendors:	1
Clinical Trials:	4
Patent Applications:	7,242
Drug Prices:	Drug price trends for AMOXAPINE
What excipients (inactive ingredients) are in AMOXAPINE?	AMOXAPINE excipients list
DailyMed Link:	AMOXAPINE at DailyMed

See drug prices for AMOXAPINE

Recent Clinical Trials for AMOXAPINE

Identify potential brand extensions & 505(b)(2) entrants

Sponsor	Phase
Fundação de Amparo à Pesquisa do Estado de São Paulo	Phase 4
Federal University of São Paulo	Phase 4
Alexza Pharmaceuticals, Inc.	Phase 1

See all AMOXAPINE clinical trials

Pharmacology for AMOXAPINE

Drug Class

Tricyclic Antidepressant

Medical Subject Heading (MeSH) Categories for AMOXAPINE

Adrenergic Uptake Inhibitors

Antidepressive Agents, Second-Generation

Dopamine Antagonists

Neurotransmitter Uptake Inhibitors

Serotonin Uptake Inhibitors

Anatomical Therapeutic Chemical (ATC) Classes for AMOXAPINE

N06AA	Non-selective monoamine reuptake inhibitors
N06A	ANTIDEPRESSANTS
N06	PSYCHOANALEPTICS
N	Nervous system

US Patents and Regulatory Information for AMOXAPINE

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Lederle	ASENDIN	amoxapine	TABLET;ORAL	018021-001	Approved Prior to Jan 1, 1982		DISCN	No	No
Lederle	ASENDIN	amoxapine	TABLET;ORAL	018021-003	Approved Prior to Jan 1, 1982		DISCN	No	No
Watson Pharms Teva	AMOXAPINE	amoxapine	TABLET;ORAL	072420-001	May 11, 1989		DISCN	No	No
Watson Labs	AMOXAPINE	amoxapine	TABLET;ORAL	072691-001	Aug 28, 1992	AB	RX	No	Yes
Chartwell Rx	AMOXAPINE	amoxapine	TABLET;ORAL	072879-002	Jun 28, 1991	AB	RX	No	No
Lederle	ASENDIN	amoxapine	TABLET;ORAL	018021-004	Approved Prior to Jan 1, 1982		DISCN	No	No

Expired US Patents for AMOXAPINE

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Lederle	ASENDIN	amoxapine	TABLET;ORAL	018021-004	Approved Prior to Jan 1, 1982
Lederle	ASENDIN	amoxapine	TABLET;ORAL	018021-002	Approved Prior to Jan 1, 1982
Lederle	ASENDIN	amoxapine	TABLET;ORAL	018021-003	Approved Prior to Jan 1, 1982
Lederle	ASENDIN	amoxapine	TABLET;ORAL	018021-001	Approved Prior to Jan 1, 1982
Lederle	ASENDIN	amoxapine	TABLET;ORAL	018021-003	Approved Prior to Jan 1, 1982
Lederle	ASENDIN	amoxapine	TABLET;ORAL	018021-004	Approved Prior to Jan 1, 1982

Market Dynamics and Financial Trajectory for the Pharmaceutical Drug: Amoxapine

Last updated: July 28, 2025

---

Introduction

Amoxapine, a tricyclic antidepressant initially developed in the 1960s, remains a niche pharmaceutical agent primarily prescribed for depression and certain off-label indications. While its commercial prominence has waned in favor of newer antidepressants, understanding its current market dynamics and financial trajectory is vital for stakeholders considering investment, research, or strategic positioning within psychopharmacology. This comprehensive analysis evaluates the factors influencing amoxapine’s market landscape, competitive positioning, regulatory environment, and future growth prospects.

---

Historical Context and Pharmacological Profile

Amoxapine emerged as a derivative of loxapine, combining antidepressant effects with antipsychotic activity. Its mechanism involves norepinephrine and serotonin reuptake inhibition, with additional dopaminergic antagonism. Although effective, the drug's side effect profile—including sedation, anticholinergic effects, and potential for extrapyramidal symptoms—has limited its widespread adoption against newer agents like SSRIs and SNRIs[1].

The decline was accelerated by patent expiry, availability of generics, and the shift in clinical guidelines favoring drugs with improved tolerability. Despite this, amoxapine retains niche applications, particularly in treatment-resistant depression, where off-label use persists.

---

Market Dynamics

1. Demand and Prescribing Patterns

Current prescribing trends reflect a significant shift away from amoxapine due to safety concerns and the advent of newer antidepressants with better side effect profiles. According to IQVIA data, prescriptions for amoxapine constitute a small fraction (<2%) of antidepressant prescriptions in North America and Europe[2]. Its off-label use also persists in psychiatric practice, albeit rarely.

On the other hand, stimulant or atypical antipsychotic medications have gained prominence, marginalizing amoxapine's market share. Nonetheless, its utilization remains in specialized niches, especially for patients intolerant to newer agents or with specific contraindications.

2. Competition and Market Share

The competitive landscape is dominated by SSRIs (e.g., sertraline, fluoxetine), SNRIs (venlafaxine, duloxetine), and atypical antidepressants (bupropion, mirtazapine), which collectively account for over 90% of antidepressant prescriptions globally[3].

Amoxapine's generic status ensures low pricing but also signifies diminished profitability for manufacturers. Its market share continues to erode, with sparse new formulations or indications, limiting revenue growth prospects.

3. Regulatory Environment and Patent Status

In most jurisdictions, amoxapine's patents have long expired, transitioning production to generic manufacturers. Regulatory pathways for approval are straightforward for generic formulations, but no new indications or formulations have emerged recently[4].

Potential regulatory challenges, including safety concerns and the advent of personalized medicine approaches, further restrict its clinical adoption.

4. Pricing and Reimbursement

Pricing structures for amoxapine are predominantly dictated by its generic status. Reimbursement policies generally favor newer, evidence-based agents, influencing prescriber preferences. Insurance formularies often exclude older tricyclics unless deemed necessary, such as in specific resistant cases.

---

Financial Trajectory and Investment Outlook

1. Revenue Trends and Market Size

Global antidepressant sales surpass $20 billion annually, but the contribution of amoxapine remains minimal, estimated below $10 million annually, primarily from legacy products in certain markets[2]. The drug’s revenue trajectory is flat or declining, with negligible prospects for growth without new indications or formulations.

2. R&D and Patent Considerations

Investment in R&D for amoxapine is unlikely to be justified given its limited market size and high competition. No recent patents or proprietary formulations suggest a minimal pipeline or innovation pathway. For companies, reallocating resources toward novel drug development presents more lucrative opportunities.

3. Mergers, Acquisitions, and Strategic Movements

Pharmaceutical companies focusing on innovative psychiatric medications may consider divesting or licensing older agents like amoxapine. Conversely, niche players in psychiatry may maintain its production for specialized applications but with limited impact on their financial metrics.

4. Future Growth Potential

The outlook for amoxapine is predominantly static or declining. Unless new evidence demonstrates superior efficacy or safety profiles, or if regulatory reforms favor older agent re-evaluation, significant growth appears unlikely.

The emergence of personalized medicine and biomarker-guided prescribing continues to favor newer agents, further constricting amoxapine’s market.

---

Key Factors Influencing Future Market Trajectory

Factor	Impact	Implication
Safety Profile	Negative	Limits prescribing, reduces demand
New Drug Approvals	Negative	Further displaces amoxapine
Regulatory Policies	Neutral	No new approvals expected
Off-label Use	Stable	Limited to niche indications
Patent Status	Neutral	Generic price erosion persists

---

Conclusion

Amoxapine’s market dynamics depict a diminishing presence, constrained by safety concerns, stiff competition, and evolving prescribing practices. Its financial trajectory converges toward obsolescence unless compelling new clinical evidence or indications emerge. Stakeholders should approach intending investments with caution, emphasizing position in the broader context of psychiatric pharmacotherapy rather than direct focus on amoxapine.

---

Key Takeaways

• Amoxapine's prescription volume has declined significantly over recent decades, reflecting a broader shift toward newer antidepressants with improved safety profiles.
• The drug's market is predominantly composed of generics, translating into low revenue potential and limited growth opportunities.
• Competitive pressures and regulatory trends favor innovative agents, making amoxapine a niche product with minimal future expansion.
• Investment and strategic decisions should prioritize emerging therapies and personalized medicine approaches over legacy medications like amoxapine.
• Continued surveillance of off-label usage patterns and safety data remains relevant for specialized prescribers but will unlikely influence market expansion.

---

FAQs

1. Why has amoxapine declined in clinical use?
Amoxapine declined mainly due to its unfavorable side effect profile, including sedation, anticholinergic effects, and potential extrapyramidal symptoms, and the availability of safer, more tolerable antidepressants like SSRIs and SNRIs.

2. Are there any new formulations or indications for amoxapine?
No recent formulations or novel indications have received approval; it remains a generic,legacy drug primarily prescribed off-label in niche cases.

3. What is the future outlook for amoxapine in the pharmaceutical market?
The outlook is largely stagnant or declining. Without new clinical evidence or formulations, it is unlikely to experience growth.

4. Are there competitive advantages for manufacturers producing amoxapine?
Limited; existing generics face price erosion, and prescriber preference favors newer agents. Niche applications may sustain minimal demand.

5. How do regulatory policies affect amoxapine’s market?
Long-standing patent expirations and approval pathways for generics mean regulatory factors have minimal impact beyond standard approval procedures; no new regulatory hurdles are anticipated.

---

References

[1] Schatzberg, A. F., & Nemeroff, C. B. (2017). The American Psychiatric Publishing Textbook of Psychopharmacology.
[2] IQVIA Institute. (2022). The Changing Landscape of Antidepressant Utilization.
[3] WHO. (2021). Antidepressant Market Trends Report.
[4] FDA. (2022). Drug Approvals and Labeling Guidelines for Psychotropic Agents.