Cefixime%2520trihidrate

# Cefixime Trihydrate ## Overview Cefixime is an oral, third-generation cephalosporin antibiotic with broad-spectrum activity against many gram-negative and some gram-positive organisms. It is stable against many beta-lactamases. The trihydrate form is the standard oral salt. ## Primary Indications - Uncomplicated urinary tract infections (UTI) caused by *E. coli*, *Proteus mirabilis*, *Klebsiella pneumoniae*. - Acute otitis media (pediatric). - Pharyngitis/tonsillitis (streptococcal). - Uncomplicated gonorrhea (urethral, cervical, rectal) – **note:** resistance is rising; many guidelines now recommend ceftriaxone as first line. - Acute exacerbations of chronic bronchitis. - *Shigellosis* and *Salmonella* gastroenteritis (in select cases). ## Adult Dosing - **Most infections:** 400 mg once daily OR 200 mg every 12 hours. - **Uncomplicated gonorrhea:** 400 mg single oral dose (often combined with azithromycin or doxycycline per local STI guidelines). - **UTI:** 400 mg once daily for 3–7 days (duration per local protocol). - Maximum daily dose: 400 mg. ## Pediatric Dosing - **General (otitis media, pharyngitis, UTI):** 8 mg/kg once daily OR 4 mg/kg every 12 hours. - Maximum daily dose: 400 mg. - **Acute otitis media:** 8 mg/kg/day as a single dose for 10 days (or 5–7 days per local guidelines). - **Pharyngitis:** 8 mg/kg once daily for 10 days. - Dosing based on weight; use ideal body weight for obese children. - **Neonates:** safety not established; avoid unless directed by specialist. ## Dose Adjustments - **Renal impairment:** CrCl 21–60 mL/min: reduce to 300 mg once daily (or 200 mg once daily for severe infections). CrCl ≤20 mL/min or on hemodialysis: 200 mg once daily. - **Hepatic impairment:** No dose adjustment required. - **Hemodialysis:** Give dose after dialysis (dialyzable). ## Contraindications - Hypersensitivity to cefixime, any cephalosporin, or beta-lactam antibiotic (cross-reactivity with penicillins possible; use caution if history of immediate hypersensitivity). - Severe anaphylactic reaction to any beta-lactam. ## Adverse Effects - **Common:** diarrhea (including *Clostridioides difficile*), nausea, dyspepsia, flatulence. - **GI:** pseudomembranous colitis can occur. - **Hematologic:** eosinophilia, transient neutropenia, thrombocytopenia. - **Hypersensitivity:** rash, urticaria, drug fever; rare Stevens-Johnson. - **Renal:** transient increases in BUN/creatinine. - **CNS:** headache, dizziness. ## Key Drug Interactions - **Warfarin/anticoagulants:** increased INR; monitor frequently. - **Oral contraceptives:** may reduce efficacy (theoretical, but clinically significant only with prolonged therapy; advise backup contraception). - **Probenecid:** reduces renal excretion, increases cefixime levels (not usually required). - **Live vaccines (typhoid, BCG, etc.):** avoid during antibiotic therapy (may reduce immunogenicity). ## Monitoring - Baseline renal function (especially in elderly or renal impairment). - Periodic CBC and renal function during prolonged therapy. - Signs of diarrhea (especially *C. difficile*). - In gonorrhea: test of cure per local guidelines (if used). ## Clinical Pearls - **Once daily dosing** is effective for most outpatient infections due to long elimination half-life (3–4 hours; prolonged in renal impairment). - **Not effective** against *Pseudomonas* or most anaerobes. - **Oral suspension** (100 mg/5 mL, 200 mg/5 mL) can be useful for pediatric or dysphagic patients; store as directed. - **Resistance:** cefixime resistance in *N. gonorrhoeae* is increasing; use only after susceptibility confirmation or as per local STI treatment protocols. - **Pregnancy Category B** – generally considered safe, but use only when clearly needed. - **Cross-reactivity:** up to 10% of penicillin-allergic patients may react; use caution. --- **Educational disclaimer:** This information is for educational purposes only and does not replace independent clinical judgment. Dosing and indications may vary by local guidelines, patient-specific factors, and antibiotic susceptibility patterns. Always verify current prescribing information (e.g., latest product monograph, local antibiogram, and health authority recommendations) before initiating therapy.