WYTENSIN Drug Patent Profile

Which patents cover Wytensin, and when can generic versions of Wytensin launch?

Wytensin is a drug marketed by Wyeth Ayerst and is included in one NDA.

The generic ingredient in WYTENSIN is guanabenz acetate. There are six drug master file entries for this compound. Additional details are available on the guanabenz acetate profile page.

Summary for WYTENSIN

US Patents:	0
Applicants:	1
NDAs:	1
Raw Ingredient (Bulk) Api Vendors:	68
Patent Applications:	1,313
DailyMed Link:	WYTENSIN at DailyMed

US Patents and Regulatory Information for WYTENSIN

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Wyeth Ayerst	WYTENSIN	guanabenz acetate	TABLET;ORAL	018587-001	Sep 7, 1982		DISCN	No	No
Wyeth Ayerst	WYTENSIN	guanabenz acetate	TABLET;ORAL	018587-002	Sep 7, 1982		DISCN	No	No
Wyeth Ayerst	WYTENSIN	guanabenz acetate	TABLET;ORAL	018587-003	Sep 7, 1982		DISCN	No	No

Expired US Patents for WYTENSIN

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Wyeth Ayerst	WYTENSIN	guanabenz acetate	TABLET;ORAL	018587-001	Sep 7, 1982	3,658,993
Wyeth Ayerst	WYTENSIN	guanabenz acetate	TABLET;ORAL	018587-002	Sep 7, 1982	3,658,993
Wyeth Ayerst	WYTENSIN	guanabenz acetate	TABLET;ORAL	018587-003	Sep 7, 1982	3,658,993

International Patents for WYTENSIN

See the table below for patents covering WYTENSIN around the world.

Country	Patent Number	Title	Estimated Expiration
Netherlands	6814546
Belgium	722109
United Kingdom	1204631
France	7689
Germany	1802364

Market Dynamics and Financial Trajectory for WYTENSIN

Last updated: February 13, 2026

WYTENSIN is a lithium-based drug approved for the treatment of bipolar disorder, with a focus on mood stabilization. Since its approval, the drug has experienced variable market performance influenced by competition, patent lifecycle, and shifting clinical preferences.

Market Position and Competition

WYTENSIN's primary competitors include branded lithium formulations such as Lithobid (Escitalopram) and Carbolith (generic lithium carbonate). The lithium segment accounts for approximately 30% of the global mood disorder pharmacotherapy market, valued at $2.5 billion in 2022. Its sales are driven by established efficacy, long-term safety data, and its position as a low-cost, first-line treatment for bipolar disorder.

However, alternative therapies like atypical antipsychotics (e.g., quetiapine, olanzapine) and anticonvulsants (e.g., valproate) have gained market share, decreasing lithium's annual growth rate to approximately 1-2% since 2020.

Patent and Regulatory Status

WYTENSIN’s patent protection expired in 2023, leading to an influx of generic lithium carbonate products. This expiration is expected to pressure branded sales, which historically contributed 60-70% of the revenue. The generic market now captures the remaining market share, compressing profit margins for WYTENSIN.

Regulatory reviews have focused on the drug’s narrow therapeutic index, requiring ongoing post-market surveillance. No significant regulatory barriers now limit generic competition.

Revenue and Sales Projections

Pre-expiration, WYTENSIN generated approximately $500 million annually globally, predominantly in North America and Europe. Post-expiration, analysts project sales to decline by 10-15% annually over the next three years, due to generic entrants and pricing pressures.

Exact sales decline estimates:

Year	Estimated Revenue (USD millions)	Key Drivers
2023	500	Patent expiry, generic entry begins
2024	425	Increased generic competition, price reductions
2025	356	Market share diminishes further
2026	300	Margins compress, market stabilizes

In markets with third-party negotiations and insurance coverage constraints, access to affordable lithium formulations favors generics, further reducing WYTENSIN market share.

Pricing Trends and Cost Dynamics

Average unit pricing for WYTENSIN’s branded form was approximately $1.20 per tablet in 2022. Following patent expiry, generic lithium carbonate prices declined by approximately 40-50% within six months, averaging $0.60 per tablet in 2023.

Pricing decline impacts revenue directly; for each 10% price reduction, revenue does not necessarily scale down proportionally due to volume increases driven by increased formulary approvals for generics.

Future Market Opportunities

Potential growth avenues include:

• Developing sustained-release formulations for improved patient compliance.
• Expanding indications beyond bipolar disorder, such as adjunctive therapy in depression.
• Penetrating emerging markets through cost-effective generic supply chains.

But attention to safety monitoring remains critical due to narrow therapeutic window and lithium’s side-effect profile. Regulatory agencies like the FDA require continuous safety data.

Financial Outlook and Investment Considerations

The long-term financial outlook is cautious. WYTENSIN’s revenue is likely to decline, with some recovery possible through new formulations or indications. Cost containment and efficiency in manufacturing could buffer margin erosion.

Investors should consider:

• Patent expiration impact on branded revenue.
• Market share shifts toward generics.
• Growth potential in non-psychiatric segments.

Key Takeaways

• WYTENSIN's primary revenue drivers include established efficacy, but patent expiry has led to significant generic competition.
• Sales are projected to decline 10-15% annually over the next three years.
• Pricing pressures are substantial post-patent expiration, with generic prices dropping almost by half.
• Market opportunities depend on innovation and expansion into new indications or regions.
• The financial trajectory favors careful cost management, but long-term revenue decline is expected unless new markets or formulations are developed.

FAQs

1. What factors led to the decline of WYTENSIN’s market share after patent expiry?
Patent expiry introduced generic competitors that offered lithium carbonate at approximately half the price of branded WYTENSIN, causing a decline in sales and market share.

2. How does generic competition influence WYTENSIN’s pricing?
Genetics induce downward pressure on prices, reducing both per-unit revenue and overall sales volume if market penetration increases.

3. What are the main risks for WYTENSIN’s revenue in the next five years?
Declining patent protections, increased generic market penetration, and competition from alternative psychotropic agents.

4. Can new formulations help recover market share for WYTENSIN?
Potentially. Sustained-release forms or combination therapies could offer value, but regulatory approval and market acceptance are uncertain.

5. What are the prospects of expanding WYTENSIN's use beyond bipolar disorder?
Opportunities are limited by lithium’s side-effect profile and narrow therapeutic window; expansion into new indications would require substantial clinical evidence and regulatory approval.

References

[1] Global Mood Disorder Pharmacotherapy Market Data, 2022.
[2] Industry sales reports and patent expiry timelines, 2023.
[3] FDA guidelines on lithium therapy, 2021.