Cefadroxil: Full Review
Cefadroxil is a first-generation cephalosporin antibiotic used to treat various bacterial infections. It is known for its effectiveness against Gram-positive bacteria and some Gram-negative bacteria.
1. Mechanism of Action
Cefadroxil works by inhibiting bacterial cell wall synthesis. It binds to penicillin-binding proteins (PBPs) in the bacterial cell wall, preventing the formation of cross-links between peptidoglycan layers. This interference weakens the cell wall and leads to bacterial lysis and death. Cefadroxil is bactericidal, meaning it kills bacteria rather than just inhibiting their growth.
2. Uses
Cefadroxil is used for treating a variety of infections, including:
- Skin and Soft Tissue Infections: Such as cellulitis, impetigo, and wound infections.
- Upper Respiratory Tract Infections: Including pharyngitis and tonsillitis.
- Urinary Tract Infections (UTIs): Including cystitis and pyelonephritis.
- Bone and Joint Infections: For example, osteomyelitis.
Cefadroxil is typically used for mild to moderate infections and can also be used as a prophylactic measure before certain surgeries.
3. Dosage and Administration
Cefadroxil is administered orally in the form of capsules or suspension. The usual dosage varies based on the infection being treated:
- Adults: 500 mg to 1 g every 12 hours, depending on the severity of the infection.
- Children: Dosing is based on weight and the infection, often ranging from 25 mg/kg to 50 mg/kg per day, divided into 1 or 2 doses.
4. Contraindications
Cefadroxil is contraindicated in:
- Patients with hypersensitivity to cephalosporins or penicillins (due to potential cross-reactivity).
- Patients with a history of severe allergic reactions to beta-lactam antibiotics.
- Severe renal impairment: Dose adjustments are required for patients with significant kidney dysfunction.
5. Side Effects
Common side effects of cefadroxil include:
- Gastrointestinal issues: Nausea, vomiting, diarrhea, and abdominal pain.
- Allergic reactions: Rash, itching, and in rare cases, anaphylaxis.
- Hematologic effects: Rarely, leukopenia, thrombocytopenia, or eosinophilia.
- Renal effects: Rare instances of interstitial nephritis or acute kidney injury.
- Superinfection: Prolonged use may lead to the overgrowth of resistant organisms, such as yeast infections.
6. Drug Interactions
- Anticoagulants: Cefadroxil can enhance the effects of anticoagulants like warfarin, increasing the risk of bleeding.
- Probenecid: May increase cefadroxil levels by inhibiting its renal excretion.
- Other nephrotoxic drugs: Caution is advised when used with drugs that affect kidney function.
7. Special Precautions
- Renal Function: Dose adjustments are needed for patients with renal impairment to avoid toxicity.
- Allergies: Patients with a history of penicillin allergy should be monitored for potential cross-reactivity.
- Superinfections: Long-term use can lead to the development of resistant organisms or fungal infections.
8. Resistance
Resistance to cefadroxil can occur through several mechanisms:
- Beta-lactamase production: Enzymes that break down cefadroxil, reducing its effectiveness.
- Altered PBPs: Bacteria may alter their PBPs to reduce cefadroxil binding.
- Efflux pumps: Some bacteria may pump cefadroxil out of the cell before it can act.
9. Storage and Stability
Cefadroxil should be stored at room temperature, away from moisture and heat. The oral suspension should be refrigerated and used within 14 days.
10. Summary
Cefadroxil is a first-generation cephalosporin effective against a range of bacterial infections, especially those caused by Gram-positive organisms. It is commonly used for skin, respiratory, urinary tract, and bone infections. While generally well-tolerated, cefadroxil can cause gastrointestinal disturbances, allergic reactions, and other side effects. Careful consideration of patient allergies, renal function, and potential drug interactions is important for effective and safe use.
