Flucytosine 250 mg Capsule, 20-count
🆔 Identity & classification
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🏷️ RxNorm drug class
This medicine belongs to the Nucleoside Analog Antifungal class.
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🏭 Manufacturer & labeler
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🩺 Clinical
- That's a great question. Flucytosine can work alone against some fungi, but the problem is that the fungus can develop resistance to it pretty quickly when it's used by itself. Pai...
- Why do I have to take flucytosine with another antifungal? Can't it work on its own?
- Yes — and this is one of the most practical tips for taking this medication. Instead of swallowing all your capsules at once, try taking a few at a time over about 15 minutes. Spre...
- The capsules are making me feel sick to my stomach. Is there anything I can do?
Patient education
Supplement & herbal interactions
Some supplements/herbs that may interact with Flucytosine — tap one for details:
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Ask a licensed pharmacist directly — free, answered by our team.
💊 What it looks like
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🧪 Inactive Ingredients / Excipients
Inactive ingredients, also called excipients, are components of the drug product other than the active ingredient. They may include fillers, dyes, coatings, preservatives, flavors, or other formulation ingredients.
💡 Tap an ingredient (hover on desktop) to see what it is and why it’s used.
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UNII H3R47K3TBD
FD&C Blue No. 1 is a synthetic blue dye approved for use in foods and medicines. It serves as a colorant to give the medication its distinctive appearance and help with product identification.
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UNII WZB9127XOA
A synthetic red dye used to color medications and make them easier to identify. It serves as a colorant in tablets, capsules, and liquid formulations.
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UNII XM0M87F357
A dark iron oxide compound that gives medicines their black or dark color. It's used as a colorant in tablets and capsules to help identify the product and make it visually distinctive.
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UNII 2G86QN327L
Gelatin is a protein derived from animal collagen, commonly used in medicines as a gelling agent and capsule material. It helps create soft or hard capsule shells that hold and release medication, and can also thicken liquid formulations.
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UNII EWQ57Q8I5X
Lactose monohydrate is a natural sugar derived from milk. It serves as a filler and binder in tablets and capsules, helping create the proper size, texture, and consistency of the medicine.
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UNII 70097M6I30
Magnesium stearate is a salt made from magnesium and stearic acid, a fatty substance. It's used in tablets and capsules as a lubricant and glidant to help ingredients flow smoothly during manufacturing and prevent sticking.
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UNII WZH3C48M4T
Potassium hydroxide is a strong alkaline chemical used in medicines to adjust and maintain the pH level of liquid formulations, helping keep the product stable and the active ingredients effective.
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UNII FZ989GH94E
Povidone is a synthetic polymer made from a plastic-like material. It acts as a binder to hold tablet ingredients together and as a disintegrant to help the tablet break apart in your stomach so the medicine can be absorbed.
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UNII 46N107B71O
Shellac is a natural resin secreted by the lac beetle. It's used as a coating on tablets and capsules to control how quickly the medicine dissolves and to improve appearance and stability.
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UNII ETJ7Z6XBU4
Silicon dioxide is a naturally occurring mineral used as a glidant and anti-caking agent. It helps powder ingredients flow smoothly and prevents clumping during manufacturing and storage.
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UNII 55X04QC32I
A strong alkaline chemical used to adjust and maintain the pH balance of liquid medicines. It helps keep the medicine stable and ensures it stays effective during storage.
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UNII 368GB5141J
A detergent and foaming agent derived from coconut or palm oil. In medications, it helps break down and mix oil and water-based ingredients, aids in tablet disintegration, and improves how the drug dissolves and spreads in the mouth or digestive system.
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UNII 5856J3G2A2
A starch-based powder made from potatoes and processed with sodium. It acts as a disintegrant, helping the tablet or capsule break apart quickly in the stomach so the medicine can be absorbed.
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UNII 7SEV7J4R1U
A powder made from a naturally occurring mineral. In medicines, talc works as a glidant and anti-caking agent, helping tablets and capsules flow smoothly during manufacturing and preventing clumping.
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UNII 15FIX9V2JP
Titanium dioxide is a bright white mineral powder commonly used as a colorant and opacifying agent. It makes pills and tablets white or lighter in color and helps make coatings non-transparent.
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UNII 059QF0KO0R
Water is a liquid solvent that dissolves and mixes ingredients together in liquid medicines, syrups, and injections. It helps distribute the active drug evenly throughout the product.
16 inactive ingredients listed in the exact product block matched to this NDC.
Where does this data come from?
ingredient classCode="IACT" elements from the exact product block matched by this NDC. Label-section narrative from DailyMed / the openFDA label index is shown separately when available.Inactive ingredient FAQ
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💲 Pricing
A drug doesn't have one price. Each row is a different public payment system, and none is what you'd pay at the counter — that depends on your insurance. The ⓘ on each row explains what it measures.
| Price system | Per each | Per package |
|---|---|---|
| Retail pharmacies payNADAC · weekly | Not in the retail survey — common for institutional, discontinued, or low-volume packs. | |
| Medicaid paysCMS SDUD · 12 mo | No recent Medicaid claims on file for this NDC — rare and low-volume NDCs are suppressed in the public data. | |
| Medicare drug plans payPart D · Q2 2026 | $31.31 | $626.23 / 20 capsule |
Where does this data come from?
🔁 Therapeutic equivalents
| Product | Labeler | Pack | NADAC/unit | TE | Status | Price vs. this |
|---|---|---|---|---|---|---|
| Ancobon 250 mg 00187-3554-10 | Bausch | 100 capsules | — | AB | FDA listed | — |
| Flucytosine 250 mg 00904-6834-07 | Major | 30 capsules | — | AB | FDA listed | — |
| Flucytosine 250 mg 23155-0860-01 | Heritage | 100 capsules | — | AB | FDA listed | — |
| Flucytosine 250 mg 40032-0771-01 | Novel | 100 capsules | — | AB | FDA listed | — |
| Flucytosine 250 mg 42385-0983-01 | Laurus | 100 capsules | — | AB | FDA listed | — |
| Flucytosine 250 mg 42794-0009-08 | Sigmapharm | 30 capsules | — | AB | FDA listed | — |
| Flucytosine 250 mg 43386-0771-01 | Lupin | 100 capsules | — | AB | FDA listed | — |
| Flucytosine 250 mgthis 50268-0331-12 | AvPAK | 20 capsules | — | AB | FDA listed | — |
| Flucytosine 250 mg 59651-0331-01 | Aurobindo | 100 capsules | — | — | FDA listed | — |
| Flucytosine 250 mg 60687-0599-21 | American | 30 capsules | — | AB | FDA listed | — |
Where does this data come from?
⏳ Availability & generic status
This product is an FDA-approved generic. Other versions of the same drug are listed under Therapeutic equivalents, least expensive first.
Where does this data come from?
📊 Medicare Part D spend CMS · PART D · 2026 (Q1)
📦 Packaging — all sizes for this product
| Package NDC | Description | Marketing start | Status |
|---|---|---|---|
| 50268-0331-12 You're viewing this | 20 BLISTER PACK in 1 BOX (50268-331-12) / 1 CAPSULE in 1 BLISTER PACK (50268-331-11) | 2021-04-12 | Active |
🧭 About this NDC listing & data coverage
What data is (and isn’t) available for this NDC — tap to expand
| NDC identity (package / product / labeler codes) | ✓ Available |
| Labeler | ✓ Available |
| Product & package description | ✓ Available |
| Marketing category & status | ✓ Available |
| Active ingredient / dosage form / route | ✓ Available |
| FDA label (SPL via DailyMed) | ✓ Available |
| Package photos | ✓ Available |
| Inactive ingredients (structured) | ✓ Available |
| NADAC pharmacy acquisition price (CMS) | — Not published for this NDC CMS publishes NADAC only for NDCs reported in its retail-pharmacy survey. |
| Orange Book / therapeutic-equivalence data | ✓ Available |
| HCPCS J-code billing crosswalk | — Not published for this NDC Most self-administered / retail products have no J-code — that is normal. |
| Medicaid utilization (CMS SDUD) | — Not published for this NDC CMS reports utilization only for NDCs with Medicaid claims above its privacy threshold. |
Questions about this listing
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Do I need a prescription for this product?
Where does this data come from?
📄 Full prescribing information FDA SPL
🚨 Boxed Warning ▾
WARNING Use with extreme caution in patients with impaired renal function. Close monitoring of hematologic, renal and hepatic status of all patients is essential. These instructions should be thoroughly reviewed before administration of Flucytosine Capsules USP.
🎯 Indications and Usage ▾
INDICATIONS AND USAGE Flucytosine Capsules USP is indicated only in the treatment of serious infections caused by susceptible strains of Candida and/or Cryptococcus . Candida: Septicemia, endocarditis and urinary system infections have been effectively treated with flucytosine. Limited trials in pulmonary infections justify the use of flucytosine.
Cryptococcus: Meningitis and pulmonary infections have been treated effectively. Studies in septicemias and urinary tract infections are limited, but good responses have been reported. Flucytosine Capsules USP should be used in combination with amphotericin B for the treatment of systemic candidiasis and cryptococcosis because of the emergence of resistance to Flucytosine Capsules USP (See MICROBIOLOGY ).
⏱️ Dosage and Administration ▾
DOSAGE AND ADMINISTRATION The usual dosage of Flucytosine Capsules USP is 50 to 150 mg/kg/day administered in divided doses at 6-hour intervals. Nausea or vomiting may be reduced or avoided if the capsules are given a few at a time over a 15-minute period. If the BUN or the serum creatinine is elevated, or if there are other signs of renal impairment, the initial dose should be at the lower level (see WARNINGS ).
Flucytosine Capsules USP should be used in combination with amphotericin B for the treatment of systemic candidiasis and cryptococcosis because of the emergence of resistance to Flucytosine Capsules USP (See MICROBIOLOGY ).
⛔ Contraindications ▾
CONTRAINDICATIONS Flucytosine Capsules USP should not be used in patients with a known hypersensitivity to the drug.
⚠️ Warnings ▾
WARNINGS Flucytosine Capsules USP must be given with extreme caution to patients with impaired renal function. Since Flucytosine Capsules USP is excreted primarily by the kidneys, renal impairment may lead to accumulation of the drug. Flucytosine Capsules USP serum concentrations should be monitored to determine the adequacy of renal excretion in such patients.
Dosage adjustments should be made in patients with renal insufficiency to prevent progressive accumulation of active drug. Flucytosine Capsules USP must be given with extreme caution to patients with bone marrow depression. Patients may be more prone to depression of bone marrow function if they: 1) have a hematologic disease, 2) are being treated with radiation or drugs which depress bone marrow, or 3) have a history of treatment with such drugs or radiation.
Bone marrow toxicity can be irreversible and may lead to death in immunosuppressed patients. Frequent monitoring of hepatic function and of the hematopoietic system is indicated during therapy.
🤒 Adverse Reactions ▾
ADVERSE REACTIONS The adverse reactions which have occurred during treatment with Flucytosine Capsules USP are grouped according to organ system affected. Cardiovascular: Cardiac arrest, myocardial toxicity, ventricular dysfunction. Respiratory: Respiratory arrest, chest pain, dyspnea.
Dermatologic: Rash, pruritus, urticaria, photosensitivity. Gastrointestinal: Nausea, emesis, abdominal pain, diarrhea, anorexia, dry mouth, duodenal ulcer, gastrointestinal hemorrhage, acute hepatic injury including hepatic necrosis with possible fatal outcome in debilitated patients, hepatic dysfunction, jaundice, ulcerative colitis, enterocolitis, bilirubin elevation, increased hepatic enzymes. Genitourinary: Azotemia, creatinine and BUN elevation, crystalluria, renal failure.
Hematologic: Anemia, agranulocytosis, aplastic anemia, eosinophilia, leukopenia, pancytopenia, thrombocytopenia, and fatal cases of bone marrow aplasia. Neurologic: Ataxia, hearing loss, headache, paresthesia, parkinsonism, peripheral neuropathy, pyrexia, vertigo, sedation, convulsions. Psychiatric: Confusion, hallucinations, psychosis.
Miscellaneous: Fatigue, hypoglycemia, hypokalemia, weakness, allergic reactions, Lyell's syndrome. To report SUSPECTED ADVERSE REACTIONS, contact AvKARE at 1-855-361-3993 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
🔄 Drug Interactions ▾
Drug Interactions Cytosine arabinoside, a cytostatic agent, has been reported to inactivate the antifungal activity of Flucytosine Capsules USP by competitive inhibition. Drugs which impair glomerular filtration may prolong the biological half-life of flucytosine.
🤰 Pregnancy ▾
Pregnancy Teratogenic Effects Flucytosine was shown to be teratogenic (vertebral fusions) in the rat at doses of 40 mg/kg/day (298 mg/M 2 /day or 0.051 times the human dose) administered on days 7 to 13 of gestation. At higher doses (700 mg/kg/day; 5208 mg/M 2 /day or 0.89 times the human dose administered on days 9 to 12 of gestation), cleft lip and palate and micrognathia were reported. Flucytosine was not teratogenic in rabbits up to a dose of 100 mg/kg/day (1423 mg/M 2 /day or 0.243 times the human dose) administered on days 6 to 18 of gestation.
In mice, 400 mg/kg/day of flucytosine (1380 mg/M 2 /day or 0.236 times the human dose) administered on days 7 to 13 of gestation was associated with a low incidence of cleft palate that was not statistically significant. Studies in pregnant rats have shown that flucytosine injected intraperitoneally crosses the placental barrier. There are no adequate and well-controlled studies in pregnant women.
Flucytosine Capsules USP should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus.
🧒 Pediatric Use ▾
Pediatric Use The efficacy and safety of Flucytosine Capsules USP have not been systematically studied in pediatric patients. A small number of neonates have been treated with 25 to 200 mg/kg/day of flucytosine, with and without the addition of amphotericin B, for systemic candidiasis. No unexpected adverse reactions were reported in these patients.
It should be noted, however, that hypokalemia and acidemia were reported in one patient who received flucytosine in combination with amphotericin B, and anemia was observed in a second patient who received flucytosine alone. Transient thrombocytopenia was noted in two additional patients, one of whom also received amphotericin B.
🆘 Overdosage ▾
OVERDOSAGE There is no experience with intentional overdosage. It is reasonable to expect that overdosage may produce pronounced manifestations of the known clinical adverse reactions. Prolonged serum concentrations in excess of 100 µg/mL may be associated with an increased incidence of toxicity, especially gastrointestinal (diarrhea, nausea, vomiting), hematologic (leukopenia, thrombocytopenia) and hepatic (hepatitis).
In the management of overdosage, prompt gastric lavage or the use of an emetic is recommended. Adequate fluid intake should be maintained, by the intravenous route if necessary, since Flucytosine Capsules USP is excreted unchanged via the renal tract. The hematologic parameters should be monitored frequently; liver and kidney function should be carefully monitored.
Should any abnormalities appear in any of these parameters, appropriate therapeutic measures should be instituted. Since hemodialysis has been shown to rapidly reduce serum concentrations in anuric patients, this method may be considered in the management of overdosage.
🧬 Clinical Pharmacology ▾
CLINICAL PHARMACOLOGY Flucytosine is rapidly and virtually completely absorbed following oral administration. Flucytosine Capsules USP is not metabolized significantly when given orally to man. Bioavailability estimated by comparing the area under the curve of serum concentrations after oral and intravenous administration showed 78% to 89% absorption of the oral dose.
Peak serum concentrations of 30 to 40 mcg/mL were reached within 2 hours of administration of a 2 g oral dose to normal subjects. Other studies revealed mean serum concentrations of approximately 70 to 80 mcg/mL 1 to 2 hours after a dose in patients with normal renal function receiving a 6-week regimen of flucytosine (150 mg/kg/day given in divided doses every 6 hours) in combination with amphotericin B. The half-life in the majority of healthy subjects ranged between 2.4 and 4.8 hours.
Flucytosine is excreted via the kidneys by means of glomerular filtration without significant tubular reabsorption. More than 90% of the total radioactivity after oral administration was recovered in the urine as intact drug. Flucytosine is deaminated (probably by gut bacteria) to 5-fluorouracil.
The area under the curve (AUC) ratio of 5-fluorouracil to flucytosine is 4%. Approximately 1% of the dose is present in the urine as the α-fluoro-β-ureido-propionic acid metabolite. A small portion of the dose is excreted in the feces.
The half-life of flucytosine is prolonged in patients with renal insufficiency; the average half-life in nephrectomized or anuric patients was 85 hours (range: 29.9 to 250 hours). A linear correlation was found between the elimination rate constant of flucytosine and creatinine clearance. In vitro studies have shown that 2.9% to 4% of flucytosine is protein-bound over the range of therapeutic concentrations found in the blood.
Flucytosine readily penetrates the blood-brain barrier, achieving clinically significant concentrations in cerebrospinal fluid Pharmacokinetics in Pediatric Patients Limited data are available regarding the pharmacokinetics of Flucytosine Capsules USP administered to neonatal patients being treated for systemic candidiasis. After five days of continuous therapy, median peak levels in infants were 19.6 mcg/mL, 27.7 mcg/mL, and 83.9 mcg/mL at doses of 25 mg/kg (N=3), 50 mg/kg (N=4), and 100 mg/kg (N=3), respectively. Mean time to peak serum levels was of 2.5 ± 1.3 hours, similar to that observed in adult patients.
A good deal of interindividual variability was noted, which did not correlate with gestational age. Some patients had serum levels > 100 mcg/mL, suggesting a need for drug level monitoring during therapy. In another study, serum concentrations were determined during flucytosine therapy in two patients (total assays performed =10).
Median serum flucytosine concentrations at steady state were calculated to be 57 ± 10 mcg/mL (doses of 50 to 125 mg/kg/day, normalized to 25 mg/kg per dose for comparison). In three infants receiving flucytosine 25 mg/kg/day (four divided doses), a median flucytosine half-life of 7.4 hours was observed, approximately double that seen in adult patients. The concentration of flucytosine in the cerebrospinal fluid of one infant was 43 mcg/mL 3 hours after a 25 mg oral dose, and ranged from 20 to 67 mg/L in another neonate receiving oral doses of 120 to 150 mg/kg/day MICROBIOLOGY Mechanism of Action Flucytosine is taken up by fungal organisms via the enzyme cytosine permease.
Inside the fungal cell, flucytosine is rapidly converted to fluorouracil by the enzyme cytosine deaminase. Fluorouracil exerts its antifungal activity through the subsequent conversion into several active metabolites, which inhibit protein synthesis by being falsely incorporated into fungal RNA or interfere with the biosynthesis of fungal DNA through the inhibition of the enzyme thymidylate synthetase. Activity In Vitro Flucytosine has been shown to be active against most strains of the following microorganisms both in vitro and in…
📦 How Supplied / Storage and Handling ▾
HOW SUPPLIED Flucytosine Capsules USP, 250 mg are size 2 hard gelatin capsule with blue opaque cap and grey opaque body imprinted with "NL 771" on the cap with black ink and "250" on the body with red ink filled with white to off white powder. NDC 50268-331-12 (10 capsules per card, 2 cards per carton). Flucytosine Capsules USP, 500 mg are size 0 hard gelatin capsule with grey opaque cap and white opaque body imprinted "NL 770" on the cap with black ink and "500" on the body with red ink, filled with white to off white powder.
NDC 50268-332-12 (10 capsules per card, 2 cards per carton). For Institutional Use Only. Dispensed in Unit Dose Package.
Store at 25°C (77°F); excursions permitted to 15°C - 30°C (59°F - 86°F). Manufactured for: AvKARE Pulaski, TN 38478 Mfg. Rev.
02/20 AV 04/21 (P)
📋 Description ▾
DESCRIPTION Flucytosine Capsules USP, an antifungal agent, is available as 250 mg and 500 mg capsules for oral administration. Each capsule also contains lactose monohydrate, colloidal silicon dioxide, talc, sodium starch glycolate, magnesium stearate and hard gelatin capsule shell which contains gelatin, purified water, black iron oxide, FD&C Blue No.1, titanium dioxide and sodium lauryl sulfate for 250 mg strength; gelatin, purified water, black iron oxide and titanium dioxide for 500 mg strength. The imprinting ink contains black iron oxide, shellac, potassium hydroxide, titanium dioxide, povidone, sodium hydroxide and FD &C Red No.
40 aluminum lake for 250 mg and 500 mg strengths. Chemically, flucytosine is 5-fluorocytosine, a fluorinated pyrimidine which is related to fluorouracil and floxuridine. It is a white or almost white crystalline powder with a molecular weight of 129.09 and the following structural formula: Click to Zoom In