Safexim (Cefixime)

Brand name: Safexim Generic name: Cefixime Drug class: Third-generation oral cephalosporin antibiotic Available strength: 200 mg tablets (also oral suspension)

Mechanism of Action

Cefixime is a beta-lactam antibiotic that inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins (PBPs), preventing cross-linking of peptidoglycan chains. It is resistant to many narrow-spectrum beta-lactamases, which gives it a broader gram-negative spectrum compared to earlier cephalosporins.

Spectrum of Activity

Activity	Organisms
Gram-positive	S. pyogenes (but weaker against staphylococci)
Gram-negative	E. coli, P. mirabilis, H. influenzae, M. catarrhalis, N. gonorrhoeae
Resistant organisms	ESBL/KPC-producing strains - not covered

Compared to other 3rd-gen cephalosporins, cefixime is less active against gram-positive cocci but provides good gram-negative enteric coverage in an oral formulation.

Approved Indications

Urinary tract infections (UTI) - caused by E. coli and P. mirabilis
Otitis media - caused by H. influenzae, M. catarrhalis, S. pyogenes
Pharyngitis/Tonsillitis - caused by S. pyogenes (though penicillin remains drug of choice)
Uncomplicated gonorrhea - historically used; however, the CDC no longer recommends cefixime as first-line for gonorrhea due to increasing resistance (intramuscular ceftriaxone is now preferred)
Typhoid fever - commonly used in the Indian subcontinent (Park's Preventive Medicine)

Dosage

Population	Dose
Adults	400 mg once daily OR 200 mg every 12 hours
Children 6 months - 12 years (<45 kg)	8 mg/kg/day in a single dose or divided every 12 hours
Duration	7-14 days depending on infection type

Pharmacokinetics

Parameter	Value
Route	Oral only (not parenteral)
Plasma half-life (t1/2)	3-4 hours
Excretion	Both renal (urine) and biliary (bile)
Bioavailability	~40-50% (oral suspension slightly higher than tablets)

Renal dose adjustment:

GFR 20-50 mL/min: standard dose
GFR 10-20 mL/min: reduced dose (consult renal dosing table)

Adverse Effects

GI disturbances (diarrhea, nausea, vomiting) - most common
Hypersensitivity reactions (rash, urticaria) - cross-reactivity with penicillin (~1-2%)
Elevated liver enzymes
Headache

Contraindications

Known allergy to cephalosporins
Caution in penicillin-allergic patients (check for cross-reactivity history)

Key Clinical Notes

Gonorrhea resistance: CDC guidelines moved away from cefixime as preferred therapy due to rising minimum inhibitory concentrations (MICs) in isolates across Asia, Europe, and North America. Ceftriaxone 500 mg IM (single dose) is now the standard. - Goodman & Gilman's Pharmacological Basis of Therapeutics; Smith & Tanagho's General Urology
Typhoid/MDR typhoid: Used for fluoroquinolone-resistant or multidrug-resistant cases, especially in South Asia. - Park's Textbook of Preventive and Social Medicine
Cefixime is available as an oral suspension, making it suitable for pediatric use.
Ceftibuten and cefdinir are oral cephalosporins with similar spectrum and pharmacokinetics to cefixime. - Goodman & Gilman's, p.1177

Summary

Safexim (cefixime) is a convenient once-daily oral 3rd-generation cephalosporin widely used for UTIs, respiratory tract infections, otitis media, and typhoid. Its gram-negative coverage is its key strength. Its role in gonorrhea has diminished due to resistance, and it does not cover Pseudomonas or MRSA.

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