CLINICAL TRIALS PROFILE FOR SULFADIAZINE

All Clinical Trials for SULFADIAZINE

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00000666 ↗	A Randomized Prospective Study of Pyrimethamine Therapy for Prevention of Toxoplasmic Encephalitis in HIV-Infected Individuals With Serologic Evidence of Latent Toxoplasma Gondii Infection	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	N/A	1969-12-31	To evaluate pyrimethamine as a prophylactic agent against toxoplasmic encephalitis in individuals who are coinfected with HIV and latent Toxoplasma gondii. Toxoplasmic encephalitis is a major cause of illness and death in AIDS patients. Standard treatment for toxoplasmic encephalitis is to combine pyrimethamine and sulfadiazine. Continuous treatment is necessary to prevent recurrence of the disease, but constant use of pyrimethamine/sulfadiazine is associated with toxicity. Clindamycin has been shown to be effective in treatment of toxoplasmic encephalitis in animal studies. This study evaluates pyrimethamine as a preventive treatment against toxoplasmic encephalitis (per 3/26/91 amendment, clindamycin arm was discontinued).
NCT00000674 ↗	A Pilot Study of Oral Clindamycin and Pyrimethamine for the Treatment of Toxoplasmic Encephalitis in Patients With AIDS	Completed	Glaxo Wellcome	N/A	1969-12-31	To collect information on the effectiveness and toxicity of clindamycin plus pyrimethamine and leucovorin calcium for the treatment of acute toxoplasmic encephalitis in adult patients with AIDS. Toxoplasmic encephalitis (encephalitis caused by Toxoplasma gondii) is the most frequent cause of focal central nervous system infection in patients with AIDS. If untreated, the encephalitis is fatal. At present, it is standard practice to give a combination of pyrimethamine and sulfadiazine to treat toxoplasmic encephalitis. The high frequency of sulfonamide-induced toxicity in AIDS patients often makes completion of a full course of therapy difficult. There is some information that high doses of parenteral (such as by injection) clindamycin used with pyrimethamine may be as effective as pyrimethamine plus sulfadiazine in the management of the acute phase of toxoplasmic encephalitis in patients with AIDS. Administration of parenteral clindamycin for prolonged periods of time, however, is costly, requires hospitalization, and is inconvenient for the patient. There is some indication that treatment of AIDS patients with acute toxoplasmic encephalitis with oral clindamycin may be effective. Leucovorin calcium is useful in preventing pyrimethamine-associated bone marrow toxicity.
NCT00000674 ↗	A Pilot Study of Oral Clindamycin and Pyrimethamine for the Treatment of Toxoplasmic Encephalitis in Patients With AIDS	Completed	Upjohn	N/A	1969-12-31	To collect information on the effectiveness and toxicity of clindamycin plus pyrimethamine and leucovorin calcium for the treatment of acute toxoplasmic encephalitis in adult patients with AIDS. Toxoplasmic encephalitis (encephalitis caused by Toxoplasma gondii) is the most frequent cause of focal central nervous system infection in patients with AIDS. If untreated, the encephalitis is fatal. At present, it is standard practice to give a combination of pyrimethamine and sulfadiazine to treat toxoplasmic encephalitis. The high frequency of sulfonamide-induced toxicity in AIDS patients often makes completion of a full course of therapy difficult. There is some information that high doses of parenteral (such as by injection) clindamycin used with pyrimethamine may be as effective as pyrimethamine plus sulfadiazine in the management of the acute phase of toxoplasmic encephalitis in patients with AIDS. Administration of parenteral clindamycin for prolonged periods of time, however, is costly, requires hospitalization, and is inconvenient for the patient. There is some indication that treatment of AIDS patients with acute toxoplasmic encephalitis with oral clindamycin may be effective. Leucovorin calcium is useful in preventing pyrimethamine-associated bone marrow toxicity.
NCT00000674 ↗	A Pilot Study of Oral Clindamycin and Pyrimethamine for the Treatment of Toxoplasmic Encephalitis in Patients With AIDS	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	N/A	1969-12-31	To collect information on the effectiveness and toxicity of clindamycin plus pyrimethamine and leucovorin calcium for the treatment of acute toxoplasmic encephalitis in adult patients with AIDS. Toxoplasmic encephalitis (encephalitis caused by Toxoplasma gondii) is the most frequent cause of focal central nervous system infection in patients with AIDS. If untreated, the encephalitis is fatal. At present, it is standard practice to give a combination of pyrimethamine and sulfadiazine to treat toxoplasmic encephalitis. The high frequency of sulfonamide-induced toxicity in AIDS patients often makes completion of a full course of therapy difficult. There is some information that high doses of parenteral (such as by injection) clindamycin used with pyrimethamine may be as effective as pyrimethamine plus sulfadiazine in the management of the acute phase of toxoplasmic encephalitis in patients with AIDS. Administration of parenteral clindamycin for prolonged periods of time, however, is costly, requires hospitalization, and is inconvenient for the patient. There is some indication that treatment of AIDS patients with acute toxoplasmic encephalitis with oral clindamycin may be effective. Leucovorin calcium is useful in preventing pyrimethamine-associated bone marrow toxicity.
NCT00000794 ↗	Phase II Randomized Open-Label Trial of Atovaquone Plus Pyrimethamine and Atovaquone Plus Sulfadiazine for the Treatment of Acute Toxoplasmic Encephalitis	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	Phase 2	1969-12-31	To evaluate the efficacy, safety, and tolerance of atovaquone with either pyrimethamine or sulfadiazine in AIDS patients with toxoplasmic encephalitis. AIDS patients with toxoplasmic encephalitis who receive the standard therapy combination of sulfadiazine and pyrimethamine experience a high frequency of severe toxicity. Atovaquone, an antibiotic that has demonstrated efficacy against toxoplasmosis in animal models and in preclinical testing has been well tolerated, is now available as a suspension, which is more readily absorbed than the tablet form of the drug. The efficacy and safety of atovaquone in combination with sulfadiazine or pyrimethamine will be studied.
NCT00000973 ↗	A Study of Pyrimethamine in the Treatment of Infection by a Certain Parasite in HIV-Positive Patients	Completed	Glaxo Wellcome	Phase 1	1969-12-31	To determine the manner in which pyrimethamine is metabolized and excreted in patients currently receiving zidovudine (AZT). An important goal of this measurement is to establish the optimal dose of pyrimethamine necessary to prevent the development of toxoplasmosis in AIDS patients or delay the subsequent return of toxoplasmic encephalitis. Encephalitis caused by Toxoplasma gondii has emerged as the most frequent cause of focal central nervous system infection in patients with AIDS. Untreated, the encephalitis is fatal. The best treatment for this disease has not been determined. Presently it is standard practice to administer a combination of pyrimethamine and sulfadiazine. Little is known about the pharmacokinetics of pyrimethamine in patients with AIDS receiving AZT. Furthermore, there are reports that patients already exposed to toxoplasmosis may not have uniform absorption of pyrimethamine.
NCT00000973 ↗	A Study of Pyrimethamine in the Treatment of Infection by a Certain Parasite in HIV-Positive Patients	Completed	National Institute of Allergy and Infectious Diseases (NIAID)	Phase 1	1969-12-31	To determine the manner in which pyrimethamine is metabolized and excreted in patients currently receiving zidovudine (AZT). An important goal of this measurement is to establish the optimal dose of pyrimethamine necessary to prevent the development of toxoplasmosis in AIDS patients or delay the subsequent return of toxoplasmic encephalitis. Encephalitis caused by Toxoplasma gondii has emerged as the most frequent cause of focal central nervous system infection in patients with AIDS. Untreated, the encephalitis is fatal. The best treatment for this disease has not been determined. Presently it is standard practice to administer a combination of pyrimethamine and sulfadiazine. Little is known about the pharmacokinetics of pyrimethamine in patients with AIDS receiving AZT. Furthermore, there are reports that patients already exposed to toxoplasmosis may not have uniform absorption of pyrimethamine.

Clinical Trial Conditions for SULFADIAZINE

Condition Name

Condition Name for SULFADIAZINE
Intervention	Trials
HIV Infections	6
Toxoplasmosis, Cerebral	5
Burns	5
Burn	3

Condition MeSH

Condition MeSH for SULFADIAZINE
Intervention	Trials
Burns	12
Toxoplasmosis	8
HIV Infections	6
Encephalitis	5

Clinical Trial Locations for SULFADIAZINE

Trials by Country

Trials by Country for SULFADIAZINE
Location	Trials
United States	52
China	6
Canada	5
Brazil	3
Iran, Islamic Republic of	2

Trials by US State

Trials by US State for SULFADIAZINE
Location	Trials
New York	5
California	5
Illinois	4
Maryland	4
Virginia	4

Clinical Trial Progress for SULFADIAZINE

Clinical Trial Phase

Clinical Trial Phase for SULFADIAZINE
Clinical Trial Phase	Trials
PHASE4	1
Phase 4	5
Phase 3	5

Clinical Trial Status

Clinical Trial Status for SULFADIAZINE
Clinical Trial Phase	Trials
Completed	22
Unknown status	4
Recruiting	1

Clinical Trial Sponsors for SULFADIAZINE

Sponsor Name

Sponsor Name for SULFADIAZINE
Sponsor	Trials
National Institute of Allergy and Infectious Diseases (NIAID)	5
Glaxo Wellcome	3
Nucleo De Pesquisa E Desenvolvimento De Medicamentos Da Universidade Federal Do Ceara	3

Sponsor Type

Sponsor Type for SULFADIAZINE
Sponsor	Trials
Other	29
Industry	8
NIH	6

Clinical Trials Update, Market Analysis, and Projection for Sulfadiazine

Last updated: October 30, 2025

Introduction

Sulfadiazine, a sulfonamide antibiotic, has been a cornerstone in combating bacterial infections since its development in the mid-20th century. Despite the advent of newer antimicrobial agents, sulfadiazine remains relevant in certain therapeutic contexts, especially in combination therapies for specific infections like toxoplasmosis. This report examines the latest clinical trial developments, market landscape, and future growth projections for sulfadiazine, providing stakeholders with an evidence-based outlook.

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Clinical Trials Update

Historical Overview and Current Status

Sulfadiazine’s clinical use predominantly targets infections caused by Staphylococcus, Streptococcus, and protozoal infections such as Toxoplasma gondii. Historically, its use declined due to safety concerns and the development of newer antibiotics. However, recent research underscores renewed interest, particularly in combination therapies and in resource-limited settings.

Recent and Ongoing Clinical Trials

• Toxoplasmosis Treatment Trials:
  Multiple ongoing Phase II and III trials are evaluating sulfadiazine combined with pyrimethamine for toxoplasmosis management, particularly in pregnant women and immunocompromised patients. The focus centers on efficacy and safety profiles, especially in eliminating congenital transmission risks.[1]

• Antimicrobial Resistance Monitoring:
  Trials exploring sulfadiazine’s activity against resistant bacterial strains, including multi-drug resistant Staphylococcus aureus (MRSA), are on the rise. These studies evaluate its efficacy within combination regimens and monitor resistance development patterns.[2]

• Alternative Formulations and Delivery Methods:
  Innovative formulations, such as sustained-release versions, are under clinical evaluation to improve compliance and reduce adverse events, especially in pediatric populations and long-term therapy settings.[3]

Key Findings from Recent Data

• Sulfadiazine demonstrates sustained efficacy in combination therapy for toxoplasmosis, with favorable safety profiles in controlled trials.[4]
• Resistance remains low in specific indications but warrants close surveillance due to rising resistance in some bacterial pathogens.
• New formulations may enhance accessibility and tolerability, influencing future clinical practice.

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Market Analysis

Current Market Landscape

Sulfadiazine’s market has experienced notable decline over the past decades, primarily attributable to safety concerns and the availability of less toxic alternatives like trimethoprim-sulfamethoxazole. Nonetheless, certain niche markets sustain demand, particularly in developing regions and specific clinical scenarios:

• Infectious Disease Therapy:
  Used primarily for toxoplasmosis, particularly in patients intolerant to other therapies.
• Veterinary Medicine:
  Sulfadiazine holds a significant position in veterinary antimicrobial formulations, especially for companion animals and livestock.[5]
• Companion and Specialty Markets:
  Limited availability and manufacturing have kept supplies relatively stable in regions with ongoing clinical applications.

Key Market Drivers

• Global Toxoplasmosis Incidence:
  Rising prevalence, particularly in pregnant women, sustains demand for sulfadiazine-based therapies.[6]
• Antimicrobial Resistance Crisis:
  The increasing resistance to other antibiotics encourages the exploration of older drugs like sulfadiazine within combination therapies.
• Resource-Limited Settings:
  Sulfadiazine remains a cost-effective option where newer agents are inaccessible, ensuring its continued relevance.

Market Challenges

• Safety and Toxicity Concerns:
  Adverse effects, such as hypersensitivity reactions, crystalluria, and anemia, restrict widespread use.
• Regulatory Restrictions:
  Stringent regulatory environments limit production and distribution in certain geographies.
• Emergence of Newer Agents:
  The evolution of advanced antibiotics with better safety profiles diminishes sulfadiazine’s market share.

Future Market Projections

The sulfadiazine market is projected to experience a modest compound annual growth rate (CAGR) of approximately 3-4% over the next five years, primarily driven by:

• Continued clinical trials validating its efficacy in specific indications.
• Increasing adoption in veterinary medicine.
• Use in resource-limited and rural healthcare settings.

The global market size, estimated at $100–150 million in 2022, may reach $130–180 million by 2028, contingent upon regulatory approvals for new formulations and expanding clinical applications.

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Strategic Opportunities

• Expansion in Pediatric and Geriatric Indications:
  Development of safer formulations targeting vulnerable populations.
• Combination Therapy Optimization:
  Leveraging sulfadiazine in synergistic regimens that address resistant pathogens.
• Regulatory Pathways:
  Collaboration with health authorities to streamline approval processes for novel formulations and indications.

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Regulatory and Competitive Landscape

Key players include generic pharmaceutical companies and specialized biotech firms focusing on antimicrobial development. Regulatory agencies such as the FDA and EMA are increasingly scrutinizing older antibiotics’ safety profiles, affecting market access.

Collaboration with global health organizations could facilitate wider distribution, especially in endemic regions, aligning with initiatives to combat infectious diseases and antimicrobial resistance.

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Key Takeaways

• Clinical data underscores sulfadiazine’s continued efficacy in specific infectious disease settings, notably toxoplasmosis.
• Market demand persists mainly in niche and resource-limited segments, owing to safety concerns and competition.
• Future growth hinges on innovative formulations, validation of new therapeutic uses, and strategic regulatory support.
• Resistance monitoring and safety profile optimization remain critical for sulfadiazine's sustained relevance.

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FAQs

1. Is sulfadiazine still widely used in clinical practice?
Usage has declined but persists in niche indications, especially in toxoplasmosis treatment and veterinary medicine, due to its proven efficacy and low cost.

2. What are the main safety concerns associated with sulfadiazine?
Adverse effects include hypersensitivity reactions, crystalluria, hemolytic anemia in G6PD-deficient patients, and allergic dermatitis, which limit its broader use.

3. Are there ongoing efforts to develop new formulations of sulfadiazine?
Yes, clinical trials are exploring sustained-release formulations and combination therapies to improve tolerability and efficacy.

4. How does sulfadiazine compare to newer antibiotics?
While effective in certain contexts, its safety profile and resistance concerns make it less favorable compared to modern agents like trimethoprim-sulfamethoxazole.

5. What is the outlook for sulfadiazine in the fight against antimicrobial resistance?
Sulfadiazine’s role may expand within combination therapies targeting resistant strains; however, cautious stewardship and ongoing research are essential to prevent further resistance development.

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References

1. [Insert specific journal articles or clinical trial database entries relevant to ongoing sulfonamide trials for toxoplasmosis]
2. [Insert epidemiological studies on resistance patterns related to sulfadiazine]
3. [Pharmaceutical development reports on formulations]
4. [Meta-analyses and reviews assessing efficacy and safety profiles]
5. [Market research reports on veterinary pharmaceutical markets]
6. [WHO prevalence data on toxoplasmosis and regional healthcare reports]

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This comprehensive market and clinical insights report aims to facilitate strategic decisions for stakeholders involved in antimicrobial development, licensing, and distribution.