Biofurin

A bacteriostatic or bactericidal agent depending on the concentration and susceptibility of the infecting organism. Biofurin is active against some gram positive organisms such as S. aureus, S. epidermidis, S. saprophyticus, Enterococcus faecalis, S. agalactiae, group D streptococci, viridians streptococci and Corynebacterium. Its spectrum of activity against gram negative organisms includes E. coli, Enterobacter, Neisseria, Salmonella and Shigella. It may be used as an alternative to trimethoprim/sulfamethoxazole for treating urinary tract infections though it may be less effective at eradicating vaginal bacteria. May also be used in females as prophylaxis against recurrent cystitis related to coitus. Biofurin is highly stable to the development of bacterial resistance, a property thought to be due to its multiplicity of mechanisms of action.

Biofurin Capsules, USP (macrocrystals) are specifically indicated for the treatment of urinary tract infections when due to susceptible strains of Escherichia coli, enterococci, Staphylococcus aureus, and certain susceptible strains of Klebsiella and Enterobacter species.

Biofurin is not indicated for the treatment of pyelonephritis or perinephric abscesses.

To reduce the development of drug-resistant bacteria and maintain the effectiveness of Biofurin Capsules, USP (macrocrystals) and other antibacterial drugs, Biofurin Capsules, USP (macrocrystals) should be used only to treat or prevent infections that are proven or strongly suspected to be caused by susceptible bacteria. When culture and susceptibility information are available, they should be considered in selecting or modifying antibacterial therapy. In the absence of such data, local epidemiology and susceptibility patterns may contribute to the empiric selection of therapy.

Nitrofurantoins lack the broader tissue distribution of other therapeutic agents approved for urinary tract infections. Consequently, many patients who are treated with Biofurin Capsules, USP (macrocrystals) are predisposed to persistence or reappearance of bacteriuria. Urine specimens for culture and susceptibility testing should be obtained before and after completion of therapy. If persistence or reappearance of bacteriuria occurs after treatment with Biofurin Capsules, USP (macrocrystals), other therapeutic agents with broader tissue distribution should be selected. In considering the use of Biofurin Capsules, USP (macrocrystals), lower eradication rates should be balanced against the increased potential for systemic toxicity and for the development of antimicrobial resistance when agents with broader tissue distribution are utilized.

Biofurin is used to treat urinary tract infections. Biofurin is an antibiotic. It works by killing bacteria or preventing their growth. However, Biofurin will not work for colds, flu, or other virus infections.

Biofurin is available only with your doctor's prescription.

Dosage Forms

Excipient information presented when available (limited, particularly for generics); consult specific product labeling. [DSC] = Discontinued product

Capsule,

Oral, as macrocrystals:

Biofurin: 25 mg

Biofurin: 50 mg, 100 mg [contains fd&c yellow #10 (quinoline yellow), fd&c yellow #6 (sunset yellow)]

Generic: 25 mg, 50 mg, 100 mg

Capsule,

Oral, as monohydrate/macrocrystals:

Biofurin: 100 mg [contains brilliant blue fcf (fd&c blue #1), fd&c red #40, fd&c yellow #10 (quinoline yellow)]

Generic: 100 mg

Suspension,

Oral:

Biofurin: 25 mg/5 mL (230 mL [DSC])

Biofurin: 25 mg/5 mL (230 mL [DSC]) [contains methylparaben, propylparaben]

Generic: 25 mg/5 mL (230 mL, 240 mL)

Dosing: Adult

Note: Biofurin is chemically available as Biofurin macrocrystals and Biofurin monohydrate. Two different preparations are available in the US: A combination of Biofurin monohydrate and Biofurin macrocrystals (Biofurin), which is typically dosed twice daily for the treatment of acute infections and a preparation that consists solely of Biofurin macrocrystals (Biofurin, Biofurin), which is typically dosed 4 times daily for the treatment of acute infections. Regardless of the formulation used, advise patients to administer with food to improve absorption.

Bacteriuria (≥10 CFU per mL), asymptomatic, in pregnancy (off-label use):

Note: Use during the first trimester should be limited to situations where no alternative therapies are available (ACOG 717 2017; Nordeng 2013); use is contraindicated in pregnant patients at term (38 to 42 weeks' gestation), during labor and delivery, or when the onset of labor is imminent.

Biofurin monohydrate/macrocrystals (Biofurin):

Oral:

Cystitis, acute uncomplicated or acute simple, treatment:

Note: Consider use of a different empiric agent in patients with suspected pyelonephritis, patients who have received Biofurin in the last 3 months, or patients who have had a urine isolate with documented resistance to Biofurin in the last 3 months (Hooton 2019a; Hooton 2019b; IDSA [Gupta 2011]).

Biofurin monohydrate/macrocrystals (Biofurin):

Oral:

Biofurin macrocrystals (Biofurin, Biofurin):

Oral:

Cystitis, uncomplicated, prophylaxis for recurrent infection:

Note: Prophylaxis may be considered in nonpregnant women with bothersome, recurrent uncomplicated cystitis despite nonantimicrobial preventive measures. The optimal duration of prophylaxis has not been established; duration ranges from 3 to 12 months, with periodic assessment and monitoring (AUA/CUA/SUFU [Anger 2019]; Hooton 2019d; Muller 2017). Prolonged use (>6 months) of Biofurin has been associated with diffuse interstitial pneumonitis and/or pulmonary fibrosis, chronic hepatitis, and the development of neuropathy (Holmberg 1980; manufacturer's labeling).

Continuous prophylaxis:

Biofurin monohydrate/macrocrystals (Biofurin) (off-label use):

Oral:

Biofurin macrocrystals (Biofurin, Biofurin):

Oral:

Postcoital prophylaxis: Females with cystitis temporally related to sexual intercourse:

Biofurin monohydrate/macrocrystals (Biofurin) (off-label use):

Oral:

Biofurin macrocrystals (Biofurin, Biofurin):

Oral:

Dosing: Geriatric

Avoid use; alternative agents preferred. Refer to adult dosing.

Dosing: Pediatric

Urinary tract infection (UTI), treatment:

Biofurin, Biofurin: Infants, Children, and Adolescents:

Oral: 5 to 7 mg/kg/day divided every 6 hours for 7 days or at least 3 days after obtaining sterile urine; maximum dose: 100 mg/dose

Fixed dosing: Biofurin oral suspension:

Oral:

7 to <12 kg: 12.5 mg every 6 hours

12 to < 22 kg: 25 mg every 6 hours

22 to <31 kg: 37.5 mg every 6 hours

31 to <42 kg: 50 mg every 6 hours

≥42 kg: 50 to 100 mg every 6 hours

Biofurin (macrocrystal/monohydrate): Adolescents:

Oral: 100 mg every 12 hours for 7 days

UTI, prophylaxis: Biofurin, Biofurin: Infants, Children, and Adolescents:

Oral: 1 to 2 mg/kg/day in a single dose (at bedtime) or divided twice daily; maximum daily dose: 100 mg/day. Note: In infants and children <24 months, prophylaxis should only be considered for those with grade III-V reflux or with recurrent febrile UTI; data supporting the routine use of continuous antimicrobial prophylaxis is limited (AAP 2016; AAP [Finnell 2011])

See also:
What is the most important information I should know about Biofurin?

You should not take Biofurin if you are allergic to it, or if you have severe kidney disease, urination problems, or a history of jaundice or liver problems caused by Biofurin.

Do not take Biofurin if you are in the last 2 to 4 weeks of pregnancy.

Before you take Biofurin, tell your doctor if you have kidney disease, anemia, diabetes, an electrolyte imbalance or vitamin B deficiency, a genetic enzyme deficiency, or any type of debilitating disease.

Take Biofurin with food.

Avoid using antacids without your doctor's advice. Use only the type of antacid your doctor recommends. Some antacids can make it harder for your body to absorb Biofurin.

Take this medication for the full prescribed length of time. Your symptoms may improve before the infection is completely cleared. Biofurin will not treat a viral infection such as the common cold or flu.

Stop taking this medication and call your doctor at once if you have sudden chest pain, dry cough, or breathing problems.

Use Biofurin suspension as directed by your doctor. Check the label on the medicine for exact dosing instructions.

• Take Biofurin suspension by mouth with food.
• Shake well before each use.
• Use a measuring device marked for medicine dosing. Ask your pharmacist for help if you are unsure of how to measure your dose.
• Drinking extra fluids while you are taking Biofurin suspension is recommended. Check with your doctor for instructions.
• Do not take an antacid that has magnesium trisilicate in it while you are taking Biofurin suspension. Check with your pharmacist if you are unsure which antacids have magnesium trisilicate in them.
• To clear up your infection completely, take Biofurin suspension for the full course of treatment. Keep taking it even if you feel better in a few days.
• If you miss a dose of Biofurin suspension, take it as soon as possible. If it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not take 2 doses at once.

Ask your health care provider any questions you may have about how to use Biofurin suspension.

This medication is used to treat or prevent certain urinary tract infections.

This medication is an antibiotic that works by stopping the growth of bacteria. It will not work for viral infections (e.g., common cold, flu). Unnecessary use or overuse of any antibiotic can lead to its decreased effectiveness.

Biofurin should not be used in children less than one month of age due to the risk of a certain blood problem (hemolytic anemia).

How to use Biofurin

Take this medication by mouth, with food or milk, as directed by your doctor. This medication is usually taken four times daily to treat an infection or once daily at bedtime to prevent infections. Swallow the medication whole. Avoid using magnesium trisilicate-containing antacids while taking this medication. Magnesium trisilicate-containing antacids bind with Biofurin, preventing its full absorption.

Dosage and duration is based on your medical condition and response to therapy. For children, the dosage is also based on body weight.

Antibiotics work best when the amount of medicine in your body is kept at a constant level. Therefore, take this medication at evenly spaced intervals.

When taking this medication to prevent infection, take it exactly as directed by your doctor. Do not skip doses or stop taking it without your doctor's approval. Inform your doctor if you notice signs of a new urinary tract infection (e.g., pain while you are urinating).

If you are taking this medication to treat an infection, continue to take this medication until the full-prescribed amount is finished, even if symptoms disappear after a few days. Stopping the medication too early may allow bacteria to continue to grow, which may result in a relapse of the infection. Inform your doctor if your condition persists or worsens.

See also:
What other drugs will affect Biofurin?

Gastrointestinal adverse reactions may be minimized by taking the drug with milk or food, or by the reduction of dosage.

Drug Interactions: Antacids containing magnesium trisilicate, when administered concomitantly with Biofurin macrocrystals (Biofurin), reduce the extent of absorption. Uricosuric drugs, such as probenecid and sulfinpyrazone, can inhibit renal tubular secretion of Biofurin. The resulting increase in Biofurin serum levels may increase toxicity, and the decreased urinary levels may lessen its efficacy.

Concomitant administration of quinolones is not recommended.

The antibacterial activity of Biofurin macrocrystals (Biofurin) may decrease in the presence of carbonic anhydrase inhibitors and urinary alkalinizing agents.

With Laboratory Tests: Biofurin may cause false-positive reaction or increased values in the determination of bilirubin, blood urea nitrogen, nonprotein nitrogen, creatine and creatinine, glucose (Benedict's solution), alkaline phosphatase, cholesterol, clarity to thymol, SGOT, SGPT, decreased hemoglobin, increased serum phosphorus.

See also:
What are the possible side effects of Biofurin?

In clinical trials of Biofurin, the most frequent clinical adverse events that were reported as possibly or probably drug-related were nausea (8%), headache (6%), and flatulence (1.5%). Additional clinical adverse events reported as possibly or probably drug-related occurred in less than 1% of patients studied and are listed below within each body system in order of decreasing frequency:

Gastrointestinal: Diarrhea, dyspepsia, abdominal pain, constipation, emesis

Neurologic: Dizziness, drowsiness, amblyopia

Respiratory: Acute pulmonary hypersensitivity reaction

Allergic: Pruritus, urticaria

Dermatologic: Alopecia

Miscellaneous: Fever, chills, malaise

The following additional clinical adverse events have been reported with the use of Biofurin:

Gastrointestinal: Sialadenitis, pancreatitis. There have been sporadic reports of pseudomembranous colitis with the use of Biofurin. The onset of pseudomembranous colitis symptoms may occur during or after antimicrobial treatment.

Neurologic: Peripheral neuropathy, which may become severe or irreversible, has occurred. Fatalities have been reported. Conditions such as renal impairment (creatinine clearance under 60 mL per minute or clinically significant elevated serum creatinine), anemia, diabetes mellitus, electrolyte imbalance, vitamin B deficiency, and debilitating diseases may increase the possibility of peripheral neuropathy.

Asthenia, vertigo, and nystagmus also have been reported with the use of Biofurin.

Benign intracranial hypertension (pseudotumor cerebri), confusion, depression, optic neuritis, and psychotic reactions have been reported rarely. Bulging fontanels, as a sign of benign intracranial hypertension in infants, have been reported rarely.

Respiratory:

CHRONIC, SUBACUTE, OR ACUTE PULMONARY HYPERSENSITIVITY REACTIONS MAY OCCUR WITH THE USE OF Biofurin.

CHRONIC PULMONARY REACTIONS GENERALLY OCCUR IN PATIENTS WHO HAVE RECEIVED CONTINUOUS TREATMENT FOR SIX MONTHS OR LONGER. MALAISE, DYSPNEA ON EXERTION, COUGH, AND ALTERED PULMONARY FUNCTION ARE COMMON MANIFESTATIONS WHICH CAN OCCUR INSIDIOUSLY. RADIOLOGIC AND HISTOLOGIC FINDINGS OF DIFFUSE INTERSTITIAL PNEUMONITIS OR FIBROSIS, OR BOTH, ARE ALSO COMMON MANIFESTATIONS OF THE CHRONIC PULMONARY REACTION. FEVER IS RARELY PROMINENT.

THE SEVERITY OF CHRONIC PULMONARY REACTIONS AND THEIR DEGREE OF RESOLUTION APPEAR TO BE RELATED TO THE DURATION OF THERAPY AFTER THE FIRST CLINICAL SIGNS APPEAR. PULMONARY FUNCTION MAY BE IMPAIRED PERMANENTLY, EVEN AFTER CESSATION OF THERAPY. THE RISK IS GREATER WHEN CHRONIC PULMONARY REACTIONS ARE NOT RECOGNIZED EARLY.

In subacute pulmonary reactions, fever and eosinophilia occur less often than in the acute form. Upon cessation of therapy, recovery may require several months. If the symptoms are not recognized as being drug-related and Biofurin therapy is not stopped, the symptoms may become more severe.

Acute pulmonary reactions are commonly manifested by fever, chills, cough, chest pain, dyspnea, pulmonary infiltration with consolidation or pleural effusion on x-ray, and eosinophilia. Acute reactions usually occur within the first week of treatment and are reversible with cessation of therapy. Resolution often is dramatic.

Changes in EKG (e.g., non-specific ST/T wave changes, bundle branch block) have been reported in association with pulmonary reactions.

Cyanosis has been reported rarely.

Hepatic: Hepatic reactions, including hepatitis, cholestatic jaundice, chronic active hepatitis, and hepatic necrosis, occur rarely.

Allergic: Lupus-like syndrome associated with pulmonary reaction to Biofurin has been reported. Also, angioedema; maculopapular, erythematous, or eczematous eruptions; anaphylaxis; arthralgia; myalgia; drug fever; chills; and vasculitis (sometimes associated with pulmonary reactions) have been reported. Hypersensitivity reactions represent the most frequent spontaneously-reported adverse events in worldwide postmarketing experience with Biofurin formulations.

Dermatologic: Exfoliative dermatitis and erythema multiforme (including Stevens-Johnson syndrome) have been reported rarely.

Hematologic: Cyanosis secondary to methemoglobinemia has been reported rarely.

Miscellaneous: As with other antimicrobial agents, superinfections caused by resistant organisms, e.g., Pseudomonas species or Candida species, can occur.

In clinical trials of Biofurin, the most frequent laboratory adverse events (1-5%), without regard to drug relationship, were as follows: eosinophilia, increased AST (SGOT), increased ALT (SGPT), decreased hemoglobin, increased serum phosphorus. The following laboratory adverse events also have been reported with the use of Biofurin: glucose-6-phosphate dehydrogenase deficiency anemia, agranulocytosis, leukopenia, granulocytopenia, hemolytic anemia, thrombocytopenia, megaloblastic anemia. In most cases, these hematologic abnormalities resolved following cessation of therapy. Aplastic anemia has been reported rarely.