Cefexime

# Cefexime ## Overview - **Classification**: Third-generation cephalosporin antibiotic. - **Mechanism**: Inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), leading to bacterial cell lysis. ## Primary Indications 1. **Acute Otitis Media (AOM)** - Treatment of bacterial ear infections. 2. **Pharyngitis/Tonsillitis** - Treatment of Streptococcus pyogenes infections. 3. **Acute Exacerbations of Chronic Bronchitis (AECB)** - Treatment of bacterial respiratory infections. 4. **Uncomplicated Gonorrhea** - Treatment of Neisseria gonorrhoeae infections. 5. **Uncomplicated Urinary Tract Infections (UTIs)** - Treatment of bacterial bladder/kidney infections. ## Adult Dosing ### Standard Dosing **Acute Otitis Media, Pharyngitis/Tonsillitis, AECB, UTIs** - **Dose**: **400 mg** - **Frequency**: Once daily OR **200 mg** every 12 hours - **Route**: Oral (PO) - **Duration**: Typically 5-10 days, depending on infection. **Uncomplicated Gonorrhea** - **Dose**: **400 mg** - **Frequency**: Single dose - **Route**: Oral (PO) - **Special Considerations**: Often co-administered with **1g azithromycin** PO single dose. ### Dose Adjustments - **Renal Impairment**: - CrCl 21-50 mL/min: **300 mg** PO daily. - CrCl <20 mL/min (or on dialysis): **200 mg** PO daily. - **Hepatic Impairment**: No specific dose adjustment needed. - **Elderly Patients**: Adjust dose based on renal function, not age alone. ## Pediatric Dosing ### Neonates (0-28 days) - **Dose**: Not generally recommended due to limited data. - **Special Notes**: Use alternative agents or consult an infectious disease specialist. ### Infants (1-12 months) - **Indication**: AOM, Pharyngitis/Tonsillitis, UTIs. - **Dose**: **8 mg/kg** - **Frequency**: Once daily OR **4 mg/kg** every 12 hours. - **Maximum**: **400 mg/day**. - **Formulation**: Oral suspension. ### Children (1-12 years) - **Indication**: AOM, Pharyngitis/Tonsillitis, UTIs. - **Dose**: **8 mg/kg** - **Frequency**: Once daily OR **4 mg/kg** every 12 hours. - **Maximum**: **400 mg/day**. - **Formulation**: Oral suspension or chewable tablets. ### Adolescents (13-18 years) - **Indication**: AOM, Pharyngitis/Tonsillitis, AECB, UTIs, Gonorrhea. - **Dose**: Adult dosing applies. **400 mg** PO daily or **200 mg** PO every 12 hours. - **Maximum**: **400 mg/day**. ## Safety Information ### Contraindications - **Absolute**: Hypersensitivity to cefixime or other cephalosporins. - **Absolute**: History of severe immediate hypersensitivity (e.g., anaphylaxis) to penicillins due to cross-reactivity risk. ### Common Adverse Effects - **Very Common (>10%)**: Diarrhea (most frequent). - **Common (1-10%)**: Nausea, abdominal pain, dyspepsia, headache, dizziness. - **Serious but Rare**: Clostridioides difficile-associated diarrhea (CDAD), severe cutaneous reactions (e.g., SJS, TEN), anaphylaxis, hemolytic anemia, thrombocytopenia. ### Key Drug Interactions - **Oral Anticoagulants (e.g., Warfarin)**: May enhance anticoagulant effect, increasing INR/bleeding risk. Monitor INR closely. - **Carbamazepine**: May increase carbamazepine levels. Monitor carbamazepine levels if co-administered. - **Probenecid**: May increase cefixime plasma concentrations. Not usually clinically significant. ## Monitoring & Follow-up - **Before Treatment**: Assess renal function (CrCl) in patients with renal impairment or at risk. - **During Treatment**: Monitor for resolution of infection symptoms. - **During Treatment**: Monitor for adverse effects, especially diarrhea. - **Clinical Signs**: Watch for severe or persistent diarrhea (possible CDAD), rash, signs of allergic reaction. ## Clinical Pearls - 💡 **Tip 1**: Cefixime is an oral-only agent; there is no IV formulation. - 💡 **Tip 2**: Convenient once or twice daily dosing improves patient adherence, especially in pediatrics. - 💡 **Tip 3**: Can be taken with or without food; taking with food may reduce GI upset. - 💡 **Tip 4**: Counsel patients to complete the entire course of therapy to prevent antibiotic resistance. > **⚠️ Important**: This information is for educational purposes only. Always consult current prescribing information, local guidelines, and clinical judgment before prescribing.