CLINICAL TRIALS PROFILE FOR NITROFURANTOIN

505(b)(2) Clinical Trials for nitrofurantoin

This table shows clinical trials for potential 505(b)(2) applications. See the next table for all clinical trials

Trial Type	Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
OTC	NCT05055544 ↗	Bearberry in the Treatment of Cystitis	Not yet recruiting	University of Pecs	N/A	2021-10-01	The goal of this study is to assess the efficacy of bearberry in uncomplicated cystitis. Uncomplicated cystitis is a disease related to the infection of the urinary bladder. Typical symptoms are dysuria, urinary urgency, and frequent voiding of small volumes. Urinary tract infections are frequent in women, usually treated with antibiotics, since the disease is usually caused by bacteria. Fosfomycin is a frequently used antibiotic for the treatment of uncomplicated cystitis. This medicine is typically prescribed by MDs. However, since uncomplicated cystitis is quite frequent, not all patients visit the doctor when experiencing the symptoms of this disease. The use of over-the-counter products (medicines and food supplements) to alleviate the symptoms is common. One of the most frequently used medicinal plants for this purpose is bearberry. Bearberry is a medicinal plant traditionally used for the treatment of cystitis. Its use is accepted by the European Medicine Agency as traditional herbal medicinal product for relief of symptoms of mild recurrent lower urinary tract infections such as burning sensation during urination and/or frequent urination in women. Although the experience gained during the traditional use and the laboratory experiments support the supposed beneficial effect of bearberry, its clinical efficacy has not been confirmed in well-designed clinical trials in comparison with standard antibiotic therapy. In this study, the efficacy of bearberry will be assessed in comparison with fosfomycin. Premenopausal women experiencing the symptoms of uncomplicated cystitis will be randomly divided into two groups. Since it will be a double-blind trial, neither the participants nor the experimenters will know who is receiving a particular treatment. In group A, patients will receive a single dose of fosfomycin powder dissolved in water and 2 placebo tablets three times a day for 7 days. In group B, patients will receive a single dose of placebo powder dissolved in water and 2 bearberry tablets three times a day for 7 days. At the beginning of the study (day 0) and on day 7, patients will be asked to fill in a questionnaire concerning their symptoms. At the same times, urine specimens will be collected to inspect the presence of bacteria in the urine. The primary goal of the trial is to assess the improvement of symptoms of uncomplicated cystitis after 7 days of treatment with the intention to analyze whether treatment with bearberry is at least as effective as fosfomycin therapy is. This will be achieved by using a validated questionnaire (Acute Cystitis Symptom Score). The presence of bacteria in urine and the frequency and severity of side effects will also be recorded and compared. During a 90-days follow-up of this study, the recurrence of urinary tract infections will be analyzed. This study will deliver important data on the efficacy and safety of bearberry in the treatment of uncomplicated cystitis.

All Clinical Trials for nitrofurantoin

Trial ID	Title	Status	Sponsor	Phase	Start Date	Summary
NCT00361998 ↗	Nitrofurantoin Macrocrystals 3 Days Versus 7 Days in the Treatment of Women With Uncomplicated Cystitis	Withdrawn	Clalit Health Services	Phase 4	2006-09-01	Our guidelines in the community recommend the use of NM for the treatment of women with community acquired UTI. While the length of treatment for uncomplicated cystitis with quinolones or TMP-SMX is three days, NM is recommended for seven days. However, there are not sufficient papers that establish the optimal length of treatment with NM in this population. The aim of this proposal is to evaluate and compare NM 3 day vs. 7 day treatment for the treatment of women with uncomplicated UTI.
NCT00361998 ↗	Nitrofurantoin Macrocrystals 3 Days Versus 7 Days in the Treatment of Women With Uncomplicated Cystitis	Withdrawn	HaEmek Medical Center, Israel	Phase 4	2006-09-01	Our guidelines in the community recommend the use of NM for the treatment of women with community acquired UTI. While the length of treatment for uncomplicated cystitis with quinolones or TMP-SMX is three days, NM is recommended for seven days. However, there are not sufficient papers that establish the optimal length of treatment with NM in this population. The aim of this proposal is to evaluate and compare NM 3 day vs. 7 day treatment for the treatment of women with uncomplicated UTI.
NCT00391651 ↗	Short Course Nitrofurantoin for Acute Cystitis	Completed	Procter and Gamble	Phase 2	2002-01-01	The purpose of this research study is to determine what the cure rates are with a 5 day course of nitrofurantoin versus the more standard 3 day course of trimethoprim/sulfamethoxazone. The study will improve our knowledge of which antibiotic and what length of therapy is best for treatment of UTI, taking into account the problem of antibiotic resistance. Procedures subjects will undergo once they have read and signed the consent are: Questions about their medical and sexual history and current symptoms of UTI. They will be asked to provide a urine sample and then randomly assigned to one of the two treatment groups. will be obtained at each visit. If they were assigned to the nitrofurantoin treatment regimen, they will also be asked to collect a urine sample at home on the third day. If the subject develops recurrent urinary symptoms or does not have resolution of symptoms after completing the initial treatment course, they will be asked to return to the clinic and provide another urine sample for analysis. They will then be treated with another standard antibiotic at no cost to them and will be withdrawn from the study at that time. The study population is women ages 18-45 with acute symptoms of a UTI without a history of UTI in the past 6 weeks.
NCT00391651 ↗	Short Course Nitrofurantoin for Acute Cystitis	Completed	University of Washington	Phase 2	2002-01-01	The purpose of this research study is to determine what the cure rates are with a 5 day course of nitrofurantoin versus the more standard 3 day course of trimethoprim/sulfamethoxazone. The study will improve our knowledge of which antibiotic and what length of therapy is best for treatment of UTI, taking into account the problem of antibiotic resistance. Procedures subjects will undergo once they have read and signed the consent are: Questions about their medical and sexual history and current symptoms of UTI. They will be asked to provide a urine sample and then randomly assigned to one of the two treatment groups. will be obtained at each visit. If they were assigned to the nitrofurantoin treatment regimen, they will also be asked to collect a urine sample at home on the third day. If the subject develops recurrent urinary symptoms or does not have resolution of symptoms after completing the initial treatment course, they will be asked to return to the clinic and provide another urine sample for analysis. They will then be treated with another standard antibiotic at no cost to them and will be withdrawn from the study at that time. The study population is women ages 18-45 with acute symptoms of a UTI without a history of UTI in the past 6 weeks.
NCT00649285 ↗	Food Study of Nitrofurantoin Monohydrate/Macrocrystals Capsules 100 mg and Macrobid® Capsules 100 mg	Completed	Mylan Pharmaceuticals	Phase 1	2002-10-01	The objective of this study was to investigate the bioequivalence of Mylan's nitrofurantoin monohydrate/macrocrystals capsules to Procter & Gamble's Macrobid® capsules following a single, oral 100 mg (1 x 100 mg) dose under fed conditions.
NCT00649506 ↗	Food Study of Nitrofurantoin Macrocrystals 100 mg Capsules and Macrodantin® 100 mg	Completed	Mylan Pharmaceuticals	Phase 1	2003-09-01	The objective of this study was to evaluate the relative bioavailability of Mylan's nitrofurantoin macrocrystals 100 mg capsules to Procter & Gamble's Macrodantin® 100 mg capsules following a single, oral 100 mg (1 x 100 mg) dose in 28 healthy, adult, non-tobacco using volunteers under fed conditions.

Clinical Trial Conditions for nitrofurantoin

Condition Name

Condition Name for nitrofurantoin
Intervention	Trials
Urinary Tract Infections	18
Urinary Tract Infection	5
Cystitis	4
Healthy	4

Condition MeSH

Condition MeSH for nitrofurantoin
Intervention	Trials
Urinary Tract Infections	42
Infections	25
Infection	21
Communicable Diseases	18

Clinical Trial Locations for nitrofurantoin

Trials by Country

Trials by Country for nitrofurantoin
Location	Trials
United States	88
Mexico	7
Spain	6
Pakistan	5
Australia	4

Trials by US State

Trials by US State for nitrofurantoin
Location	Trials
North Carolina	6
Texas	6
Pennsylvania	5
Ohio	5
California	5

Clinical Trial Progress for nitrofurantoin

Clinical Trial Phase

Clinical Trial Phase for nitrofurantoin
Clinical Trial Phase	Trials
PHASE4	7
PHASE2	1
PHASE1	2

Clinical Trial Status

Clinical Trial Status for nitrofurantoin
Clinical Trial Phase	Trials
Completed	22
Recruiting	16
Not yet recruiting	9

Clinical Trial Sponsors for nitrofurantoin

Sponsor Name

Sponsor Name for nitrofurantoin
Sponsor	Trials
GlaxoSmithKline	4
Mylan Pharmaceuticals	3
Altamash Institute of Dental Medicine	3

Sponsor Type

Sponsor Type for nitrofurantoin
Sponsor	Trials
Other	92
Industry	13
NIH	3

Nitrofurantoin Clinical Trials Update and Market Projection (2026–2036): Pipeline Status, FDA/Regulatory Landscape, and Revenue Outlook

Last updated: July 27, 2026

Nitrofurantoin is an established oral antibacterial for uncomplicated urinary tract infections (uUTIs). Clinical activity is dominated by line extensions (formulations, dosing regimens) and comparative/safety studies rather than new molecular entity (NME) development. The near-to-mid term market is driven by sustained uUTI demand, guideline positioning in uncomplicated cystitis, and ongoing substitution dynamics as prescribers balance efficacy, tolerability, and kidney-function use. A clear view of late-stage global pipeline milestones is not available from the provided input set.

What clinical trials are currently recruiting or ongoing for nitrofurantoin?

Answer: Publicly visible clinical trial activity for nitrofurantoin is typically concentrated in formulation studies, bioavailability comparisons (including macrocrystalline vs. monohydrate/macrocrystalline), adherence/tolerability studies, and real-world outcomes. Trial volume tends to be higher in the “comparative effectiveness and safety” category than in novel therapeutic targets.

Which trial types show the most activity

Common patterns seen in nitrofurantoin trial portfolios:

• Bioavailability and pharmacokinetic bridging for alternate oral presentations.
• Comparative studies versus other oral uUTI agents in uncomplicated cystitis settings.
• Safety and renal-function stratification studies (practical prescribing constraints).
• Short-course regimen evaluation (duration optimization).
• Adherence, tolerability, and patient-reported outcome studies.

Where trials typically run

• North America and Europe dominate comparative trials and safety cohorts.
• Smaller regional studies focus on local brand equivalents and formulation substitution.

How is the nitrofurantoin clinical pipeline evolving in 2025–2027?

Answer: The pipeline direction is incremental: no widespread sign of a late-stage “new mechanism” nitrofurantoin program. Market-facing development is more likely to target patentable formulation improvements, dosing convenience, or regulatory strategy for specific presentations.

Key pipeline themes by development stage

• Early-stage (Phase 1/PK): Bridging and bioequivalence (oral solid oral forms).
• Phase 2/3 (if present): Randomized comparative uUTI trials, safety endpoints, and non-inferiority designs.
• Post-approval (Phase 4): Renal impairment use guidance, pulmonary/hepatic safety monitoring in practice, and resistance surveillance studies.

What is the nitrofurantoin market size and how fast is it growing?

Answer: Nitrofurantoin’s market growth is modest and tied to uUTI incidence, prescribing guideline alignment, and generic penetration. Pricing pressure is persistent, so volume growth typically matters more than unit price.

Demand drivers

• High incidence of uncomplicated cystitis.
• Guideline inclusion for uUTI, particularly when microbiology supports susceptibility.
• Continued reliance in outpatient settings due to oral administration and historical efficacy data.

Key headwinds

• Antimicrobial stewardship restrictions and local resistance patterns.
• Safety considerations influencing prescribing in patients with reduced renal function.
• Competitive pressure from other oral uUTI agents (e.g., fosfomycin, pivmecillinam where available, trimethoprim-sulfamethoxazole depending on resistance).

What pricing and generic substitution dynamics affect nitrofurantoin revenue?

Answer: Nitrofurantoin is heavily genericized in many markets, limiting pricing power. Revenue exposure largely tracks:

• Prescriber switching among low-cost generics.
• Formulation preference (macrocrystalline vs. monohydrate/macrocrystalline).
• Competitive tendering and pharmacy reimbursement policies.

Commercial structure likely to dominate

• Multiple ANDAs reduce long-run pricing.
• Brand-to-generic shifts reduce absolute revenue; margin depends on procurement costs and manufacturing scale.

When does nitrofurantoin lose exclusivity and what remains patent-protected?

Answer: Nitrofurantoin’s active substance is long off patent in most jurisdictions. Market protection, where any exists, tends to be limited to specific formulations, combinations, or method-of-use claims tied to defined dosing regimens or safety/renal-use guidance.

Typical residual IP that can matter

• Controlled-release or alternate crystal-form formulations.
• Patents around manufacturing processes or particle-size specifications.
• Method-of-use claims around patient selection (renal thresholds, risk stratification) where legally enforceable.

What is the Orange Book status of nitrofurantoin in the US?

Answer: Nitrofurantoin is widely represented by generic entries in the US market. Any meaningful exclusivity usually attaches at the product level for specific ANDA references or formulation-specific listings rather than to the base molecule.

What Orange Book disclosures usually govern

• Patents listed to cover a specific nitrofurantoin drug product (dose form, strength).
• Expiration dates and possible pediatric exclusivity or marketing exclusivity on a product basis.

Which companies are selling nitrofurantoin and how concentrated is the market?

Answer: The market is fragmented among multiple generic manufacturers. Concentration varies by country and the specific dosage form (and sometimes by whether a formulation is branded or an ANDA product tied to a particular reference).

Typical competitor set

• US: large generic manufacturers and regional distributors for oral nitrofurantoin capsules/tablets.
• EU/UK: generics and local brand equivalents for uUTI.
• Emerging markets: mixed availability with variable quality and supply continuity.

What competitive landscape risks exist for nitrofurantoin (resistance, shortages, regulation)?

Answer: Nitrofurantoin is generally viewed as a stable option for uncomplicated cystitis, but the main risks are operational and stewardship driven:

• Resistance and susceptibility shifts in uropathogens.
• Manufacturing capacity or API supply interruptions.
• Regulatory pressure via stewardship recommendations and labeling.

Antimicrobial resistance exposure

• Resistance patterns vary geographically.
• Higher rates of resistance reduce empirical use and can shift prescribers toward alternate agents.

How strong is the patent estate for nitrofurantoin?

Answer: The patent estate for nitrofurantoin is generally weak as a molecule-level barrier. The relevant IP strength is usually confined to formulation-specific and method-of-use claims tied to specific product presentations and product-level regulatory listings.

Practical implication for entry

• If a formulation is protected by enforceable product-level patents, generic entry can be delayed in that narrow lane.
• If only old molecule IP remains, entry timing is dominated by regulatory/market economics rather than litigation constraints.

What formulations of nitrofurantoin are on the market and do they differ commercially?

Answer: The dominant differentiation is by oral dosage form and release characteristics, most notably:

• Nitrofurantoin monohydrate/macrocrystals (commonly used for uUTI dosing regimens).
• Nitrofurantoin macrocrystals (historical presentation in some markets).

Commercial impact of formulation choice

• Prescriber familiarity drives default selection.
• Pharmacy stocking and payer reimbursement lock in product mix over time.
• Any patient tolerability differences influence switching.

What patent litigation affects nitrofurantoin generic launches (Paragraph IV and settlements)?

Answer: Nitrofurantoin litigation is not typically a major recurring headline compared with newer uUTI agents that are still within molecule-level exclusivity windows. Where disputes occur, they are usually tied to formulation-specific patents in a narrow product lane.

What to watch in future litigation cycles

• Patent challenges tied to product-level formulation claims.
• Scheduling and outcomes of district court cases, then any Federal Circuit appeals.

What generic entry risks exist for nitrofurantoin in major markets?

Answer: For most markets, entry risk is already realized given broad generic penetration. Remaining risks concentrate in:

• Formulation-specific patents listed to block certain ANDA pathways.
• Regulatory labeling constraints affecting the accepted indication or patient selection language.
• Supply-chain constraints that can delay availability even after legal entry.

How does nitrofurantoin compare with other uncomplicated UTI antibiotics (fosfomycin, TMP-SMX, beta-lactams)?

Answer: Nitrofurantoin competes primarily on the balance of:

• Oral outpatient use.
• Historical efficacy in uncomplicated cystitis.
• Safety and kidney-function eligibility constraints that can change prescribing behavior.

Competitive positioning that affects share

• Where susceptibility supports its use, nitrofurantoin is often a preferred option.
• In higher-resistance geographies, competitors with broader susceptibility may gain.

What is the FDA regulatory status of nitrofurantoin and are there label changes that affect use?

Answer: Nitrofurantoin has an established US label for uncomplicated cystitis and includes safety-related language tied to organ toxicity risks. Prescribing is influenced by patient renal function and risk-benefit assessments.

Regulatory signals to monitor

• Changes in renal-impairment labeling language.
• Safety communications regarding rare but serious adverse events.
• Any updates affecting duration recommendations.

Nitrofurantoin 2026–2036 market projection: scenarios and revenue drivers

Answer: Growth is likely low single-digit to mid single-digit annually in volume terms, constrained by generics and antimicrobial stewardship, with revenue growth more sensitive to utilization volume than to price.

Projection logic (high level)

• Base demand: uUTI incidence and outpatient antibiotic prescribing rates.
• Utilization retention: guideline adherence and clinician familiarity.
• Substitution: patient and pathogen factors that push use to alternative agents.
• Regulatory and safety: any tightening of renal-use language reduces eligible population.

Scenario table

Scenario	Volume trend	Price trend	Revenue trend	Main assumptions
Base case	Low single-digit growth	Flat to slight down	Low single-digit growth	Stable stewardship and resistance patterns
Downside	Flat to mild decline	Downward pricing	Low/negative growth	Resistance increases or tighter renal-use criteria
Upside	Higher single-digit growth	Stable pricing	Mid single-digit growth	Sustained guideline positioning and stable safety perception

Key takeaways

• Nitrofurantoin remains a mainstay for uncomplicated cystitis, with development focused on incremental formulation and comparative/safety evidence rather than new mechanism drug discovery.
• Market growth is constrained by generic penetration; revenue outlook depends mainly on volume and utilization share more than pricing.
• Patent leverage is mostly product-level and formulation-specific; molecule-level exclusivity is effectively exhausted in most jurisdictions.
• Primary commercial risks are antimicrobial stewardship effects, resistance and susceptibility shifts, and safety/renal eligibility labeling that can reduce eligible patient volume.
• Long-run competitive dynamics continue to center on oral alternatives for uUTI and prescriber guideline behavior.

FAQs

1. Do nitrofurantoin resistance patterns change local prescribing guidelines?
2. Which renal function labeling restrictions most affect nitrofurantoin utilization for uUTI?
3. Are bioequivalence differences between nitrofurantoin formulations clinically meaningful in practice?
4. How do tendering and payer reimbursement influence which nitrofurantoin generic wins pharmacy shelf share?
5. What safety signals (pulmonary/hepatic) most influence clinician risk-benefit decisions for nitrofurantoin?

References

1. FDA. Orange Book: Approved Drug Products with Therapeutic Equivalence Evaluations (nitrofurantoin entries).
2. FDA. Drug Labeling and Safety Communications for nitrofurantoin.
3. Clinical practice guidelines on management of uncomplicated urinary tract infections (uUTI), including antimicrobial selection recommendations for nitrofurantoin.