1. Clinical Overview
Cefixime is a third-generation oral cephalosporin antibiotic with broad-spectrum bactericidal activity against Gram-negative bacteria, including beta-lactamase producing strains. It is widely used in India for treating community-acquired respiratory, urinary, and gastrointestinal infections due to its good oral bioavailability, convenient once-daily dosing, and established safety profile.
| Onset | Duration | Bioavailability |
|---|---|---|
| Peak plasma concentrations are achieved within 2 to 6 hours post oral administration. | Approximately 24 hours, supporting once-daily dosing. | 40-50% (oral suspension); 30-40% (tablet/capsule). Absorption is not significantly affected by food. |
2. Mechanism of Action
Cefixime is a bactericidal antibiotic. It inhibits bacterial cell wall synthesis by binding to one or more of the penicillin-binding proteins (PBPs) located inside the bacterial cell wall. This binding inhibits the final transpeptidation step of peptidoglycan synthesis, leading to the formation of a defective cell wall and subsequent osmotic lysis of the bacterium.
3. Indications & Uses
- Acute bacterial exacerbations of chronic bronchitis
- Acute community-acquired pneumonia (mild to moderate)
- Uncomplicated urinary tract infections (cystitis)
- Acute otitis media (in children)
- Pharyngitis and Tonsillitis (caused by Streptococcus pyogenes)
- Uncomplicated gonorrhea (urethral and cervical)
- Acute uncomplicated typhoid and paratyphoid fever (Enteric fever)
4. Dosage & Administration
Adult Dosage: 200 mg orally every 12 hours OR 400 mg once daily. For uncomplicated gonorrhea: 400 mg as a single dose.
Administration: Can be taken with or without food. Taking with food may minimize gastrointestinal upset. Tablet should be swallowed whole with a glass of water. For oral suspension, shake the bottle well before each use. Use the measuring spoon/cup provided. Complete the full prescribed course even if symptoms improve.
5. Side Effects
Common side effects may include:
- Diarrhea or loose stools (most common)
- Nausea
- Abdominal pain
- Dyspepsia
- Flatulence
- Headache
- Vaginitis or genital pruritus
6. Drug Interactions
| Drug | Effect | Severity |
|---|---|---|
| Warfarin and other Coumarin Anticoagulants | Cefixime may potentiate anticoagulant effect by reducing vitamin K-producing gut flora and possibly by other mechanisms, increasing risk of bleeding. | Major |
| Aminoglycosides (e.g., Gentamicin) | Increased potential for nephrotoxicity. Monitor renal function. | Moderate |
| Potent Diuretics (e.g., Furosemide) | May increase the risk of nephrotoxicity due to altered renal excretion. | Moderate |
| Probenecid | Inhibits renal tubular secretion of cefixime, leading to increased and prolonged blood levels of cefixime. | Moderate |
| Oral Contraceptives | Potential for reduced efficacy of oral contraceptives due to altered gut flora. Advise use of a non-hormonal backup method. | Moderate |
| Antacids containing Aluminum or Magnesium | May reduce the absorption rate of cefixime, but the overall extent of absorption is not significantly affected. | Minor |
7. Patient Counselling
- DO complete the entire course of therapy, even if you feel better after a few days.
- DO take it at evenly spaced intervals for best effect.
- DO inform your doctor if you are pregnant, planning pregnancy, or breastfeeding.
- DO inform your doctor about all other medicines you are taking, including OTC drugs and supplements.
- DONT skip doses.
- DONT share your medicine with others.
- DONT take antacids within 2 hours of taking cefixime.
8. Toxicology & Storage
Overdose: Nausea, vomiting, epigastric distress, diarrhea. Seizures may occur with significant overdose, especially in patients with renal failure.
Storage: Store at room temperature (15-25°C), protected from light, moisture, and excessive heat. Keep in the original container, tightly closed. Keep out of reach of children. For reconstituted oral suspension: Store in refrigerator (2-8°C). Do not freeze. Discard any unused portion after 14 days.