Winfax500 mg

Winfax is a second-generation oral cephalosporin antibiotic prodrug used to treat a variety of bacterial infections caused by susceptible organisms.

Established / FDA-approved indications

• Pharyngitis and tonsillitis
• Acute bacterial otitis media
• Acute bacterial maxillary sinusitis
• Acute bacterial exacerbations of chronic bronchitis
• Uncomplicated skin and skin-structure infections
• Uncomplicated urinary tract infections
• Uncomplicated gonorrhea (cervical/urethral)
• Early Lyme disease

Guideline-supported / commonly used indications

• Community-acquired pneumonia, typically as part of a broader treatment protocol
• Bone and joint infections, as oral step-down therapy after initial parenteral treatment

Winfax should be used only for infections proven or strongly suspected to be caused by susceptible bacteria, based on culture and susceptibility data or local epidemiology, to reduce the development of drug-resistant bacteria.

Each Cefuroxime Axetil tablet contains Cefuroxime Axetil equivalent to 125 mg, 250 mg, or 500 mg of cefuroxime. Cefuroxime Axetil is also available as a powder for oral suspension, providing cefuroxime 125 mg/5 mL after reconstitution. Cefuroxime Axetil is the 1-acetoxyethyl ester (prodrug) of cefuroxime.

Winfax is a semi-synthetic, second-generation cephalosporin antibiotic administered orally as an inactive ester prodrug. After absorption, Winfax is hydrolyzed by non-specific esterases in the intestinal mucosa and blood to release the active moiety, cefuroxime, which exerts bactericidal activity against a broad range of Gram-positive and Gram-negative bacteria.

Winfax is used to treat respiratory tract infections, ear and sinus infections, urinary tract infections, skin infections, and certain sexually transmitted and tick-borne infections caused by organisms susceptible to cefuroxime.

Winfax belongs to the second-generation cephalosporin class of beta-lactam antibiotics.

Cefuroxime Axetil is an orally-absorbed prodrug that is rapidly hydrolyzed during and after absorption to cefuroxime, the pharmacologically active compound.

Mechanism of action

Cefuroxime binds to penicillin-binding proteins (PBPs) located on the bacterial cell wall, inhibiting the final transpeptidation (cross-linking) step of peptidoglycan synthesis. This weakens the bacterial cell wall, leading to cell lysis and death, making Cefuroxime Axetil bactericidal against susceptible organisms.

Spectrum of activity

Cefuroxime Axetil is active against many Gram-positive organisms (e.g., Streptococcus pyogenes, Streptococcus pneumoniae, methicillin-susceptible Staphylococcus aureus) and Gram-negative organisms (e.g., Haemophilus influenzae, Moraxella catarrhalis, Escherichia coli, Klebsiella pneumoniae, Neisseria gonorrhoeae), including many beta-lactamase-producing strains, due to relative stability against certain beta-lactamases.

Pharmacokinetics

Absorption of Cefuroxime Axetil is enhanced when taken with food. Peak plasma concentrations occur approximately 2-3 hours after dosing. Cefuroxime is eliminated primarily unchanged by the kidneys via glomerular filtration and tubular secretion.

Winfax tablets should be swallowed whole with water and not crushed or chewed, as crushing exposes the bitter-tasting active drug. Winfax may be taken with or without food, but administration with food increases absorption and is recommended. If the oral suspension formulation of Winfax is used, shake well before each dose and use the provided measuring device; tablets and suspension are not interchangeable on a milligram-for-milligram basis.

The following interactions with Winfax are clinically significant:

• Gastric acid-reducing agents (antacids, H2-receptor antagonists, proton pump inhibitors): Reduced gastric acidity can lower the absorption and peak plasma concentration of Winfax. If an antacid is required, it should be taken at least 1 hour before or 2 hours after Winfax.
• Probenecid: Competitively inhibits renal tubular secretion of cefuroxime, increasing and prolonging plasma cefuroxime concentrations; concurrent use with Winfax is generally not recommended unless specifically directed by a physician.
• Oral contraceptives: As with other antibiotics, Winfax may theoretically reduce the efficacy of estrogen-containing oral contraceptives; an additional non-hormonal method of contraception may be advised during treatment.
• Laboratory test interference: Winfax may cause false-positive results in some urine glucose tests using copper-reduction methods and may interfere with certain assays for serum/urine creatinine.

Winfax is generally well tolerated. Reported adverse effects include:

Common

• Diarrhea
• Nausea and vomiting
• Abdominal discomfort
• Headache
• Vaginal itching or vaginitis (in females)

Less common

• Skin rash or urticaria
• Transient elevation of liver enzymes
• Eosinophilia

Rare but serious

• Severe hypersensitivity/anaphylaxis
• Stevens-Johnson syndrome and toxic epidermal necrolysis
• Clostridioides difficile-associated diarrhea/colitis (see Precautions and Warnings)
• Seizures (typically with very high doses or in renal impairment)

Patients should seek prompt medical attention for any severe rash, difficulty breathing, swelling, or persistent diarrhea while taking Winfax.

Pregnancy: Winfax should be used during pregnancy only if clearly needed and if the potential benefit justifies the potential risk to the fetus. Published epidemiologic data have not shown an increased risk of major birth defects, but there are no adequate, well-controlled studies to confirm safety definitively. A physician should be consulted before using Winfax during pregnancy.

Lactation: Cefuroxime is excreted into human breast milk in small amounts. Winfax should be used with caution in breastfeeding women, and only under medical advice, with the infant monitored for gastrointestinal effects such as diarrhea or thrush.

Hypersensitivity: Serious and occasionally fatal hypersensitivity (anaphylactic) reactions have been reported with cephalosporins; discontinue Winfax immediately if a reaction occurs. Use with caution in patients with a history of penicillin allergy due to possible cross-reactivity (see Contraindications).

Clostridioides difficile-associated diarrhea (CDAD): Winfax, like nearly all antibacterial agents, can cause CDAD ranging from mild diarrhea to fatal colitis. Evaluate patients who develop diarrhea during or after treatment.

Superinfection: Prolonged use of Winfax may result in overgrowth of non-susceptible organisms, including fungi.

Absorption and food: Absorption of Winfax is enhanced by food; taking it with meals is recommended, particularly for higher doses.

Renal impairment: Dose adjustment of Winfax is required in patients with significant renal impairment.

Antibiotic stewardship: Take Winfax exactly as prescribed by your physician; do not stop, extend, skip doses, or share this medicine with others without medical advice, as inappropriate use promotes antibiotic resistance.

Laboratory interference: Winfax may cause false results in certain glucose and Coombs' tests (see Interactions).

Overdosage with Winfax may cause central nervous system effects, including increased cerebral irritability, and, particularly in patients with renal impairment, seizures/convulsions. There is no specific antidote. If an overdose of Winfax is suspected, seek immediate medical attention or contact a poison control center; supportive care should be provided, and hemodialysis or peritoneal dialysis may help reduce serum cefuroxime concentrations in severe cases. Do not attempt to manage a suspected overdose of Winfax at home without medical guidance.

Store Winfax tablets at room temperature (below 30°C), away from light and moisture. Keep out of reach of children. If using the reconstituted oral suspension of Winfax, store in a refrigerator and discard any unused portion after the period stated on the product label (commonly 10 days).

Pediatric use: Safety and effectiveness of Winfax have been established for children 3 months of age and older for approved indications; weight-based dosing should be used. Safety and efficacy in infants under 3 months have not been established. Tablets are not recommended for children unable to swallow them whole; use the oral suspension instead (see Pediatric Uses).

Geriatric use: No overall differences in safety or effectiveness have been observed with Winfax in elderly patients compared to younger adults, but elderly patients are more likely to have reduced renal function, requiring dose adjustment.

Renal impairment: The dosage interval of Winfax should be adjusted in patients with creatinine clearance below 30 mL/min; consult a physician for individualized dosing.

Hepatic impairment: No specific dose adjustment of Winfax is established; use with routine clinical caution.

Pregnancy and lactation: See Pregnancy and Lactation section.

The duration of Winfax therapy depends on the infection being treated, ranging from a single dose (uncomplicated gonorrhea) to 20 days (early Lyme disease); most common infections are treated for 7-10 days. Patients should complete the full prescribed course of Winfax even if symptoms improve early, to ensure eradication of the infection and reduce the risk of antibiotic resistance and relapse.

Winfax tablets do not require reconstitution. The Winfax powder for oral suspension must be reconstituted by adding the specified amount of water to the bottle as directed on the product label, then shaking well to form a uniform suspension (typically providing 125 mg/5 mL of cefuroxime). The reconstituted suspension of Winfax should be shaken before each use, stored as directed on the label (commonly refrigerated), and any unused portion discarded after the period stated on the label (commonly 10 days).

Cephalosporins (second-generation); Beta-lactam antibiotics.

Cefuroxime Axetil is an inactive ester prodrug that is hydrolyzed during absorption to release cefuroxime, the active antibacterial moiety. Cefuroxime exerts a bactericidal effect by binding to penicillin-binding proteins (PBPs) in the bacterial cell wall, thereby inhibiting the transpeptidation step of peptidoglycan (cell wall) biosynthesis. This disrupts cell wall integrity, leading to bacterial cell lysis and death. Cefuroxime Axetil shows relative stability against many bacterial beta-lactamase enzymes, broadening its spectrum of activity compared with first-generation cephalosporins.

B

Winfax tablets are approved for use in children 3 months of age and older for specific indications such as pharyngitis/tonsillitis and acute otitis media, using weight-based dosing (typically 20-30 mg/kg/day in two divided doses, not exceeding the adult dose). Safety and efficacy of Winfax have not been established in infants younger than 3 months. Because the tablet form has a bitter taste when crushed, children who cannot swallow tablets whole should receive the oral suspension formulation of Winfax rather than a crushed tablet. Tablets and oral suspension are not interchangeable on a milligram-per-milligram basis, so a physician's specific formulation and dose should be followed.