Cefex250 mg

Cefex is a first-generation oral cephalosporin antibiotic that is FDA-approved and guideline-supported for the treatment of infections caused by susceptible bacteria, including:

• Respiratory tract infections - such as bronchitis and pneumonia caused by susceptible organisms (established use)
• Otitis media - middle ear infection in children and adults (established use)
• Skin and skin structure infections - including cellulitis, abscesses, and wound infections caused by susceptible Staphylococcus and Streptococcus species (established use)
• Bone and joint infections - osteomyelitis caused by susceptible organisms (established use)
• Genitourinary tract infections - including cystitis and other urinary tract infections; note prostatitis is not consistently covered by Cefex's spectrum and is generally considered an off-label/less-preferred use
• Streptococcal pharyngitis/tonsillitis - as an alternative agent in penicillin-tolerant patients, requiring a minimum 10-day course for eradication (guideline-supported use)

Cefex is not effective against infections caused by methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas species, or most Enterococcus species, and should only be used for infections proven or strongly suspected to be caused by susceptible bacteria.

Each capsule/tablet of Cephalexin contains Cephalexin (as monohydrate) as the active ingredient, available in strengths such as 250 mg and 500 mg. An oral suspension form containing Cephalexin 125 mg/5 mL or 250 mg/5 mL after reconstitution is also available. Excipients vary by manufacturer and formulation.

Cefex is a semi-synthetic, first-generation cephalosporin antibiotic for oral administration. It is chemically related to the penicillin class of antibiotics and works by interfering with bacterial cell wall synthesis, resulting in a bactericidal effect against a range of gram-positive and some gram-negative organisms. Cefex is widely used in Bangladesh and internationally for common bacterial infections of the skin, respiratory tract, ear, and urinary tract, and has a safety and efficacy profile similar to other first-generation cephalosporins such as cefadroxil.

Cefex belongs to the first-generation cephalosporin antibiotic class, a subgroup of beta-lactam antibiotics structurally related to penicillins.

Cephalexin is a bactericidal agent that exerts its effect by inhibiting bacterial cell wall synthesis. It binds to penicillin-binding proteins (PBPs) located inside the bacterial cell wall, interfering with the transpeptidation step of peptidoglycan synthesis, which weakens the cell wall and leads to bacterial cell lysis and death.

After oral administration, Cephalexin is rapidly and almost completely absorbed from the gastrointestinal tract. Peak serum concentrations are reached within about 1 hour. It is widely distributed into body tissues and fluids, is minimally metabolized, and is excreted largely unchanged in the urine via glomerular filtration and tubular secretion, with a serum half-life of approximately 0.5 to 1.2 hours in patients with normal renal function.

Cefex can be taken with or without food; food may reduce stomach upset. Swallow capsules/tablets whole with water. Shake the oral suspension well before measuring each dose using an appropriate measuring device.

Cefex has the following well-established clinically significant interactions:

• Metformin: Cefex can increase plasma concentrations of metformin by interfering with its renal elimination via organic cation transporters, which may increase the risk of metformin-related side effects; blood glucose monitoring and dose adjustment of metformin may be needed.
• Probenecid: Probenecid inhibits renal tubular secretion of Cefex, increasing and prolonging its blood levels; concurrent use is generally not recommended unless specifically directed by a physician.
• Oral anticoagulants (e.g., warfarin): Cephalosporins including Cefex may prolong prothrombin time in some patients; monitor coagulation parameters if used together.
• Live bacterial vaccines (e.g., typhoid vaccine): Antibiotics including Cefex may reduce the effectiveness of live bacterial vaccines; spacing of administration is recommended.

Most patients tolerate Cefex well. Reported side effects include:

Common

• Diarrhea (most common)
• Nausea and vomiting
• Abdominal discomfort or dyspepsia
• Headache

Less common / rare

• Skin rash, urticaria, and other hypersensitivity reactions
• Angioedema and, rarely, anaphylaxis
• Eosinophilia
• Transient elevation of liver enzymes
• Genital and oral candidiasis (yeast overgrowth)
• Reversible interstitial nephritis (rare)
• Blood dyscrasias including neutropenia and hemolytic anemia (rare)
• Clostridioides difficile-associated diarrhea, which can range from mild diarrhea to severe, life-threatening colitis and may occur during treatment or up to two months after stopping Cefex

Seek prompt medical attention for severe or watery diarrhea, signs of allergic reaction (rash, swelling, difficulty breathing), or unusual bleeding/bruising while taking Cefex.

Pregnancy: Animal reproduction studies have not shown evidence of fetal harm with Cefex, and it is classified under pregnancy category B. However, adequate and well-controlled human studies are limited. Cefex should be used during pregnancy only if clearly needed, and only after the potential benefit to the mother has been weighed against the potential risk to the fetus; consult a physician before use.

Lactation: Cefex is excreted in low concentrations in human breast milk. While generally considered compatible with breastfeeding by most references, caution is advised, and infants should be monitored for possible effects on gut flora such as diarrhea or candidiasis. Consult a physician before using Cefex while breastfeeding.

The following precautions apply when using Cefex:

• Penicillin cross-sensitivity: Use with caution in patients with a history of penicillin allergy due to possible cross-reactivity (see Contraindications).
• Clostridioides difficile-associated diarrhea (CDAD): Antibiotic use, including Cefex, can lead to overgrowth of C. difficile. Evaluate promptly if severe or persistent diarrhea occurs.
• Renal impairment: Use with caution and adjust dose/interval in patients with reduced kidney function.
• Prolonged use: May result in overgrowth of non-susceptible organisms, including fungi; monitor for superinfection during prolonged therapy.
• Seizure risk: High doses, particularly in patients with renal impairment, have rarely been associated with CNS effects including seizures.
• Antibiotic stewardship: Take exactly as prescribed by your physician; do not stop, extend, skip doses, or share this medicine with others without medical advice.
• False test results: Cefex may cause a false-positive reaction for glucose in urine with certain non-enzymatic tests and a false-positive direct Coombs test.

Symptoms of Cefex overdose may include nausea, vomiting, epigastric distress, diarrhea, and, in rare severe cases, hematuria or seizures, particularly in patients with impaired renal function. There is no specific antidote. In case of suspected overdose, seek immediate medical attention or contact a poison control center/emergency services right away. Treatment is generally supportive; hemodialysis may assist in removing Cefex from the body in cases of severe renal impairment, under medical supervision.

Store at room temperature (below 30°C), away from light and moisture. Reconstituted oral suspension should be kept refrigerated and used within the period specified on the label (typically 14 days), then discarded. Keep out of reach of children.

Renal impairment

Dose and/or dosing interval of Cefex should be reduced in patients with creatinine clearance below 60 mL/min, under physician guidance.

Hepatic impairment

No specific dose adjustment is established, but Cefex should be used with general caution and monitoring in patients with significant hepatic dysfunction.

Elderly

Elderly patients may have reduced renal function; dose adjustment based on renal status may be needed. Monitor for signs of adverse effects.

Pediatric

See Pediatric Uses section for age-specific dosing.

Duration of Cefex therapy is typically 7-14 days depending on the infection being treated. Streptococcal pharyngitis/tonsillitis requires a minimum of 10 days to ensure eradication and prevent complications such as rheumatic fever. The full prescribed course should always be completed even if symptoms resolve earlier.

For the oral suspension powder form: add the specified amount of water to the bottle in two portions, shaking well after each addition, to yield the labeled concentration (e.g., 125 mg/5 mL or 250 mg/5 mL) of Cefex. Shake well before each use. Refer to the manufacturer's instructions on the product label for exact reconstitution volume.

First-generation cephalosporin antibiotic; beta-lactam antibiotic class.

Cephalexin exerts a bactericidal effect by binding to penicillin-binding proteins (PBPs) and inhibiting the transpeptidation step of bacterial cell wall (peptidoglycan) synthesis, leading to cell wall instability, lysis, and death of susceptible bacteria.

B

Cefex is approved for use in pediatric patients over 1 year of age for susceptible bacterial infections, with dosing calculated on a mg/kg/day basis as outlined in the Dosage and Administration section. Safety and efficacy in infants under 1 year of age have not been well established, and Cefex should be used in this age group only under close physician supervision. As with all antibiotic use in children, the full prescribed course should be completed, and children should be monitored for gastrointestinal side effects and signs of allergic reaction.