What it's for (Indications)
- Cefadroxil is a broad-spectrum, first-generation cephalosporin antibiotic primarily indicated for the treatment of various susceptible bacterial infections.
- These include infections of the skin and skin structure, such as impetigo, erysipelas, cellulitis, and pyoderma, caused by susceptible strains of Staphylococcus aureus (including penicillinase-producing strains) and Streptococcus pyogenes.
- Additionally, it is prescribed for uncomplicated urinary tract infections (UTIs), including cystitis and pyelonephritis, when caused by susceptible strains of Escherichia coli, Proteus mirabilis, and Klebsiella species.
- Pharyngitis and tonsillitis due to Streptococcus pyogenes are also common indications, serving as an alternative for penicillin-allergic patients (who do not have immediate-type hypersensitivity).
- The selection of cefadroxil should be based on susceptibility testing and local epidemiological data, or clinical judgment when susceptibility data are not available.
Dosage Information
| Type | Guideline |
|---|---|
| Standard | The dosage of cefadroxil must be individualized based on the severity and type of infection, the patient's age, weight, and renal function. For adults and adolescents, common dosages range from 1 to 2 grams per day, administered orally, either as a single dose or divided into two doses (e.g., 500 mg twice daily or 1000 mg once daily). For skin and skin structure infections, a typical adult regimen is 1 gram daily, often divided. For uncomplicated urinary tract infections, a 1-gram daily dose or 2 grams daily (divided) may be prescribed, depending on the severity. Pediatric dosing is weight-based, generally 30 mg/kg/day to 50 mg/kg/day, divided into one or two doses. Dosage adjustments are crucial for patients with impaired renal function to prevent accumulation and potential toxicity, requiring careful monitoring of creatinine clearance. The duration of therapy varies, typically 7-14 days, and should be continued for at least 48-72 hours after the patient becomes asymptomatic or evidence of bacterial eradication is obtained, especially for streptococcal infections to prevent acute rheumatic fever. |
Safety & Warnings
Common Side Effects
- Cefadroxil, like other cephalosporin antibiotics, can cause a range of adverse effects, although it is generally well-tolerated.
- The most frequently reported side effects are gastrointestinal in nature, including nausea, vomiting, dyspepsia, abdominal pain, and diarrhea.
- Skin reactions are also relatively common, manifesting as rash, pruritus, and urticaria.
- Hypersensitivity reactions, ranging from mild skin manifestations to severe anaphylaxis, can occur and require immediate medical attention.
- Other less common but significant adverse effects include genitourinary symptoms such as vaginitis and candidiasis due to altered normal flora.
- Hematologic abnormalities like eosinophilia, thrombocytopenia, and leukopenia have been reported rarely.
- Central nervous system effects, including dizziness, headache, and nervousness, are infrequent.
- Long-term or inappropriate use can lead to the overgrowth of non-susceptible organisms, potentially resulting in superinfections, most notably Clostridioides difficile-associated diarrhea (CDAD), which can manifest as mild diarrhea to severe colitis.
- Patients should be advised to report any persistent or severe side effects to their healthcare provider.
Serious Warnings
- Black Box Warning: Cefadroxil does not carry a formal FDA-mandated Black Box Warning. However, clinicians and patients should be acutely aware of several serious safety concerns that warrant careful consideration, often referred to as 'Serious Warnings.' The most critical of these is the potential for severe hypersensitivity reactions, including anaphylaxis, especially in individuals with a history of allergy to penicillins or other beta-lactam antibiotics. Such reactions can be life-threatening and necessitate immediate medical intervention, including epinephrine and airway management. Another significant warning is the risk of Clostridioides difficile-associated diarrhea (CDAD), which can range from mild diarrhea to fatal pseudomembranous colitis. This can occur during or even several months after treatment and requires prompt diagnosis and management. Furthermore, renal function impairment requires careful dosage adjustment to prevent drug accumulation and potential toxicity, and patients with a history of gastrointestinal disease, particularly colitis, should use this medication with caution. Physicians should thoroughly review patient medical history and current medications to mitigate these serious risks.
- Cefadroxil requires careful administration and monitoring due to several important warnings.
- Patients with a history of hypersensitivity to penicillin or other beta-lactam antibiotics should be closely monitored, as cross-reactivity can occur, potentially leading to severe allergic reactions, including anaphylaxis.
- Before initiating therapy, a thorough inquiry should be made concerning previous hypersensitivity reactions to cephalosporins, penicillins, or other drugs.
- If an allergic reaction occurs, the drug should be discontinued immediately, and appropriate emergency measures instituted.
- Prolonged use of cefadroxil may result in the overgrowth of non-susceptible organisms, necessitating careful observation for superinfections.
- Of particular concern is Clostridioides difficile-associated diarrhea (CDAD), which can range in severity from mild diarrhea to fatal colitis, and can occur more than two months after antibiotic cessation.
- Patients with a history of gastrointestinal disease, particularly colitis, should receive cefadroxil with caution.
- Renal function should be assessed before and during therapy, especially in patients with pre-existing renal impairment, as dosage adjustments are essential to prevent drug accumulation and potential nephrotoxicity.
- This medication should be used with caution in nursing mothers as it is excreted in breast milk.
How it Works (Mechanism of Action)
Cefadroxil exerts its bactericidal activity by inhibiting bacterial cell wall synthesis. As a first-generation cephalosporin, its primary target is the penicillin-binding proteins (PBPs) located on the inner bacterial cell membrane. These PBPs are crucial enzymes involved in the final stages of peptidoglycan synthesis, a vital component of the bacterial cell wall that provides structural integrity. By irreversibly binding to and inactivating these PBPs, cefadroxil disrupts the cross-linking of peptidoglycan strands, leading to a defective and weakened cell wall. This compromised cell wall integrity results in increased osmotic pressure within the bacterial cell, ultimately causing cell lysis and bacterial death. Cefadroxil exhibits good activity against many gram-positive bacteria, including most staphylococci and streptococci, and some gram-negative bacteria like E. coli, P. mirabilis, and Klebsiella species, by interfering with their ability to build and maintain a functional cell wall, essential for their survival and replication.