Cefadroxil

# Cefadroxil ## Overview - **Classification**: First-generation cephalosporin antibiotic - **Mechanism**: Inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), leading to cell lysis and bacterial death. ## Primary Indications 1. **Urinary Tract Infections (UTIs)** - Uncomplicated and complicated UTIs. 2. **Skin and Soft Tissue Infections (SSTIs)** - Such as cellulitis, impetigo, erysipelas. 3. **Pharyngitis/Tonsillitis** - Due to *Streptococcus pyogenes*. ## Adult Dosing ### Standard Dosing **Skin and Soft Tissue Infections, Uncomplicated UTIs** - **Dose**: **1 g** - **Frequency**: Once daily OR **500 mg** twice daily - **Route**: Oral - **Duration**: Typically 7-14 days depending on infection severity **Pharyngitis/Tonsillitis (Streptococcus pyogenes)** - **Dose**: **1 g** - **Frequency**: Once daily OR **500 mg** twice daily - **Route**: Oral - **Duration**: **10 days** **Complicated UTIs** - **Dose**: **1 g** - **Frequency**: Twice daily - **Route**: Oral ### Dose Adjustments - **Renal Impairment**: Dose adjustments required based on CrCl: - CrCl 25-50 mL/min: **500 mg** q24h - CrCl 10-25 mL/min: **500 mg** q36h - CrCl <10 mL/min: **500 mg** q48h (or after hemodialysis) - **Hepatic Impairment**: No specific dose adjustment generally recommended. - **Elderly Patients**: Adjust based on renal function; monitor for adverse effects. ## Pediatric Dosing ### Neonates (0-28 days) - **Cefadroxil is generally not recommended in neonates** due to limited safety and efficacy data. - **Special Notes**: Alternative antibiotics are preferred for this age group. ### Infants (1-12 months) - **Dose**: **30 mg/kg/day** - **Frequency**: Divided into two doses (e.g., q12h) - **Maximum**: Do not exceed adult doses (e.g., **1g/day** for pharyngitis, **2g/day** for other infections) ### Children (1-12 years) - **Pharyngitis/Tonsillitis (Streptococcus pyogenes)**: - **Dose**: **30 mg/kg/day** - **Frequency**: Once daily OR divided into two doses (q12h) - **Maximum**: **1 g/day** - **Duration**: **10 days** - **Other Infections (SSTIs, UTIs)**: - **Dose**: **30 mg/kg/day** - **Frequency**: Divided into two doses (q12h) - **Maximum**: **2 g/day** ### Adolescents (13-18 years) - **Dose**: Adult dosing guidelines apply. - **Maximum**: Up to **2 g/day** depending on indication. ## Safety Information ### Contraindications - **Absolute**: Hypersensitivity to cefadroxil or other cephalosporins. - **Absolute**: History of severe immediate hypersensitivity reaction (e.g., anaphylaxis) to penicillins. ### Common Adverse Effects - **Common (1-10%)**: Diarrhea, nausea, vomiting, abdominal pain. - **Common (1-10%)**: Skin rash, itching, genital pruritus. - **Serious but Rare**: Clostridium difficile-associated diarrhea (CDAD), severe hypersensitivity reactions (anaphylaxis, Stevens-Johnson syndrome). ### Key Drug Interactions - **Probenecid**: May increase cefadroxil plasma concentrations; monitor for increased effects/toxicity. - **Warfarin**: May enhance anticoagulant effect; monitor INR closely. - **Aminoglycosides/Loop Diuretics**: Concomitant use may increase risk of nephrotoxicity. ## Monitoring & Follow-up - **Before Treatment**: Assess renal function if impairment suspected (e.g., elderly, pre-existing kidney disease). - **During Treatment**: Monitor for resolution of infection symptoms. - **Clinical Signs**: Watch for signs of allergic reaction (rash, hives, difficulty breathing), severe diarrhea (possible CDAD), or new onset of yeast infections. ## Clinical Pearls - 💡 **Take with food**: Cefadroxil can be taken with food to minimize gastrointestinal upset. - 💡 **Complete full course**: Emphasize completing the entire prescribed course, even if symptoms improve, to prevent resistance. - 💡 **Cross-reactivity**: While low, be aware of potential cross-reactivity with penicillins (approx. 1-10%). Counsel patients on prior allergic reactions. > **⚠️ Important**: This information is for educational purposes only. Always consult current prescribing information, local guidelines, and clinical judgment before prescribing.