Cefadroxil: Potent Oral Antibiotic for Bacterial Infections
Cefadroxil
Cefadroxil is a first-generation cephalosporin antibiotic renowned for its broad-spectrum bactericidal activity and favorable pharmacokinetic profile. As a beta-lactam antibiotic, it exerts its effect by inhibiting bacterial cell wall synthesis, leading to osmotic instability and cell death. Its extended half-life compared to other first-generation cephalosporins allows for less frequent dosing, enhancing patient compliance. Clinicians frequently prescribe cefadroxil for common outpatient infections due to its reliable efficacy against Gram-positive organisms and some Gram-negative bacteria.
Features
- Chemical classification: First-generation cephalosporin antibiotic
- Mechanism of action: Inhibition of bacterial cell wall synthesis via binding to penicillin-binding proteins
- Spectrum of activity: Effective against Gram-positive cocci (including penicillinase-producing staphylococci) and some Gram-negative bacilli
- Pharmacokinetics: Oral bioavailability >90%, serum half-life of approximately 1.5 hours, primarily renal excretion
- Formulations: Available as 500 mg and 1 g tablets, and oral suspension (250 mg/5 mL and 500 mg/5 mL)
- Stability: Remains stable in gastric acid, enabling effective oral administration
Benefits
- Demonstrates excellent tissue penetration, particularly in skin, soft tissue, and urinary tract
- Provides convenient once or twice-daily dosing regimen due to extended elimination half-life
- Shows minimal protein binding (approximately 20%), ensuring high free drug concentration at infection sites
- Exhibits bactericidal activity rather than bacteriostatic action, promoting faster clinical resolution
- Maintains activity against beta-lactamase producing strains of Staphylococcus aureus
- Offers well-tolerated profile with generally mild adverse effects in most patient populations
Common use
Cefadroxil is indicated for the treatment of various bacterial infections caused by susceptible organisms. Primary indications include uncomplicated skin and skin structure infections, such as cellulitis, impetigo, and wound infections, particularly those caused by Staphylococcus aureus and Streptococcus pyogenes. It is also commonly prescribed for pharyngitis and tonsillitis when caused by Group A beta-hemolytic streptococci. Additionally, cefadroxil demonstrates efficacy in treating urinary tract infections, including cystitis and pyelonephritis, caused by Escherichia coli, Proteus mirabilis, and Klebsiella pneumoniae. Some off-label uses include dental infections and prophylactic administration in certain surgical procedures where Gram-positive coverage is indicated.
Dosage and direction
The dosage of cefadroxil must be individualized based on the infection severity, causative organism, and patient’s renal function. For adults with normal renal function, the typical dosage ranges from 1 to 2 grams daily, administered either as a single dose or in divided doses every 12 hours. For streptococcal pharyngitis, a 10-day course of 1 gram once daily or 500 mg twice daily is recommended. Pediatric dosing is typically 30 mg/kg/day in divided doses every 12 hours. Patients with impaired renal function require dosage adjustment based on creatinine clearance: for CrCl 25-50 mL/min, administer 500 mg every 12 hours; for CrCl 10-25 mL/min, 500 mg every 24 hours; for CrCl <10 mL/min, 500 mg every 36 hours. Administration with food may minimize gastrointestinal discomfort without significantly affecting absorption.
Precautions
Patients should complete the entire prescribed course of therapy even if symptoms improve to prevent development of resistant organisms. Use with caution in patients with history of gastrointestinal disease, particularly colitis, as antibiotic use may cause pseudomembranous colitis. Monitor renal function periodically during prolonged therapy, as cefadroxil is primarily excreted unchanged by the kidneys. Exercise caution in patients with history of mild penicillin allergy, as cross-reactivity may occur in approximately 5-10% of cases. Prolonged use may result in overgrowth of nonsusceptible organisms, including fungi; monitor for superinfection. Use during pregnancy only if clearly needed, as adequate human studies are lacking, though animal studies have not demonstrated teratogenic effects.
Contraindications
Cefadroxil is contraindicated in patients with known hypersensitivity to cephalosporin antibiotics or any component of the formulation. Absolute contraindication exists for patients with history of anaphylactic reaction to penicillins or other beta-lactam antibiotics due to potential cross-reactivity. Should not be administered to patients with previous history of cephalosporin-associated hemolytic anemia or severe cutaneous adverse reactions. Contraindicated in patients with known phenylketonuria when using formulations containing phenylalanine. Not recommended for treatment of meningitis due to inadequate cerebrospinal fluid penetration.
Possible side effect
The most commonly reported adverse effects involve the gastrointestinal system, including nausea (3-5%), diarrhea (2-4%), and abdominal pain (1-2%). Dermatological reactions may occur, with rash developing in approximately 1.5% of patients and pruritus in 1%. Transient elevations in liver enzymes (AST, ALT) have been observed in 2-3% of patients. Less frequent side effects include vaginitis or vaginal discharge (2%), headache (1.5%), and dizziness (1%). Rare but serious adverse effects include pseudomembranous colitis, Stevens-Johnson syndrome, toxic epidermal necrolysis, and hemolytic anemia. Hematological changes such as eosinophilia, neutropenia, and thrombocytopenia have been reported in less than 1% of patients.
Drug interaction
Probenecid concurrently administered with cefadroxil may decrease renal tubular secretion, increasing and prolonging cefadroxil blood levels. Oral anticoagulants may see enhanced effects due to potential reduction in vitamin K-producing gut flora. Concomitant use with nephrotoxic drugs (aminoglycosides, potent diuretics) may increase risk of renal dysfunction. Absorption may be impaired when taken with iron supplements or antacids containing aluminum or magnesium. May reduce efficacy of oral typhoid vaccine; separate administration by at least 72 hours. Potential interaction with live bacterial vaccines due to antibiotic effect on normal gut flora.
Missed dose
If a dose of cefadroxil is missed, it should be taken as soon as remembered unless it is almost time for the next scheduled dose. In that case, the missed dose should be skipped and the regular dosing schedule resumed. Patients should not double the dose to make up for a missed administration. Maintaining consistent antibiotic levels is important for therapeutic efficacy, but occasional missed doses are unlikely to significantly impact treatment outcomes if the overall regimen is maintained. Healthcare providers should be consulted if multiple doses are missed or if uncertainty exists about how to manage missed doses.
Overdose
Cefadroxil overdose is generally well-tolerated due to its wide therapeutic index. Symptoms of overdose may include nausea, vomiting, epigastric distress, and diarrhea. In cases of massive overdose, particularly in patients with renal impairment, neurotoxicity including seizures may occur. Management is primarily supportive, with maintenance of hydration and electrolyte balance. Gastric lavage may be considered if ingestion occurred within a short time frame. Hemodialysis may be effective in removing cefadroxil from the bloodstream, particularly in patients with renal impairment. There is no specific antidote for cefadroxil overdose. Serum levels are not routinely monitored in clinical practice.
Storage
Store cefadroxil tablets at controlled room temperature between 20-25°C (68-77°F) in a tightly closed container, protected from light and moisture. Keep oral suspension refrigerated between 2-8°C (36-46°F) after reconstitution; discard any unused portion after 14 days. Do not freeze the liquid formulation. Keep all medications out of reach of children and pets. Do not store in bathroom cabinets where humidity and temperature fluctuations may degrade the product. Check expiration dates before use and properly dispose of expired medication through take-back programs or following FDA-recommended disposal methods.
Disclaimer
This information is provided for educational purposes only and does not constitute medical advice. The content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition or medication regimen. Never disregard professional medical advice or delay in seeking it because of something you have read in this document. The manufacturer and publisher are not responsible for any errors or omissions or for any consequences from application of the information contained herein.
Reviews
Clinical studies demonstrate cefadroxil’s efficacy with cure rates of 85-95% for skin and soft tissue infections and 80-90% for urinary tract infections. Meta-analyses show comparable efficacy to other first-generation cephalosporins with the advantage of less frequent dosing. Patient satisfaction surveys indicate high compliance rates due to the convenient dosing schedule. Some studies note slightly higher incidence of gastrointestinal side effects compared to later-generation cephalosporins but overall favorable tolerability profile. Long-term clinical experience spanning decades supports its position as a reliable option for outpatient antibiotic therapy.