Usage
Cefetamet is a third-generation cephalosporin antibiotic indicated for treating various bacterial infections. These include:
- Respiratory Tract Infections: Bronchitis (acute and chronic exacerbations), pneumonia, pharyngitis/tonsillitis, sinusitis, tracheobronchitis.
- Urinary Tract Infections: Cystitis, pyelonephritis, gonococcal urethritis.
- Other Infections: Otitis media (ear infections), skin and soft tissue infections, bone and joint infections.
Pharmacological Classification: Antibiotic
Mechanism of Action: Cefetamet inhibits bacterial cell wall synthesis by binding to and inactivating penicillin-binding proteins (PBPs). This disruption leads to cell wall instability, rupture, and ultimately bacterial death.
Alternate Names
Cefetamet pivoxil hydrochloride (prodrug form)
Brand Names: Altamet, Globocef, Recocef, Tenafet, and others (brand names vary regionally).
How It Works
Pharmacodynamics: Cefetamet exerts bactericidal activity against a broad spectrum of gram-positive and gram-negative bacteria, including Streptococcus pneumoniae, Streptococcus pyogenes, Haemophilus influenzae, Moraxella catarrhalis, Escherichia coli, Proteus spp., Klebsiella spp., and Neisseria gonorrhoeae. It is not effective against staphylococci, enterococci, Pseudomonas spp., or Bacteroides fragilis.
Pharmacokinetics: Cefetamet pivoxil, the oral prodrug, is well-absorbed after oral administration, particularly when taken with food. It is hydrolyzed to the active metabolite, cefetamet. Cefetamet has a volume of distribution approximating the extracellular fluid space and minimal protein binding. It is primarily eliminated unchanged by renal excretion with a half-life of approximately 2.2 hours.
Mode of Action: Cefetamet binds to specific PBPs located on the bacterial cell membrane. These PBPs are crucial enzymes involved in the final transpeptidation step of peptidoglycan synthesis, a critical component of the bacterial cell wall. By inhibiting PBPs, cefetamet disrupts cell wall integrity, leading to bacterial cell lysis and death.
Elimination Pathways: Primarily renal excretion.
Dosage
Standard Dosage
Adults:
- 500 mg twice daily (bid). Dosages up to 1g bid have been used in some clinical trials for specific infections.
Children (over 6 months):
- 10 mg/kg twice daily.
- Up to 20 mg/kg twice daily for some infections (e.g., otitis media).
- In toddlers (1-2 years) doses of 20-30 mg/kg/day split bid have been effective in some cases.
Special Cases:
- Elderly Patients: Dose adjustment is generally not necessary, although a slight reduction in elimination may occur. Monitor renal function.
- Patients with Renal Impairment: Dosage adjustment may be needed based on creatinine clearance. Hemodialysis removes cefetamet, so supplemental doses may be required.
- Patients with Hepatic Dysfunction: Exercise caution in patients with active liver disease or elevated ALT levels.
- Patients with Comorbid Conditions: Consider individual patient factors such as other medications and underlying medical conditions.
Clinical Use Cases
Dosing recommendations for specific clinical use cases are not explicitly mentioned in the source material and generally follow the standard adult or pediatric dosing guidelines mentioned above. The dose may be adjusted in severe or complicated infections in consultation with an infectious disease specialist.
Dosage Adjustments
Adjustments are primarily based on renal function.
Side Effects
Common Side Effects
- Diarrhea
- Nausea
- Vomiting
- Abdominal pain
- Headache
Rare but Serious Side Effects
- Allergic reactions (rash, itching, swelling, severe dizziness, trouble breathing)
- Clostridium difficile-associated diarrhea (pseudomembranous colitis)
- Seizures (especially in patients with renal impairment)
Long-Term Effects
Generally, not associated with long-term adverse effects when used for short-term treatment of infections.
Adverse Drug Reactions (ADR)
Severe allergic reactions (anaphylaxis), pseudomembranous colitis, seizures.
Contraindications
- Hypersensitivity to cefetamet, other cephalosporins, or penicillins.
Drug Interactions
- Probenecid: May increase cefetamet serum concentrations.
- Aminoglycosides: Increased risk of nephrotoxicity.
- Anticoagulants (e.g., warfarin): Increased risk of bleeding.
- Live bacterial vaccines (e.g., BCG): Decreased vaccine effectiveness.
Pregnancy and Breastfeeding
- Pregnancy: Limited data available. Use only if clearly needed and after careful risk-benefit assessment.
- Breastfeeding: Small amounts of cefetamet may be excreted in breast milk. Monitor infants for potential side effects (e.g., diarrhea, thrush).
Drug Profile Summary
- Mechanism of Action: Inhibits bacterial cell wall synthesis by binding to PBPs.
- Side Effects: Diarrhea, nausea, vomiting, abdominal pain, headache. Rarely, allergic reactions, C. difficile infection, seizures.
- Contraindications: Hypersensitivity to cephalosporins or penicillins.
- Drug Interactions: Probenecid, aminoglycosides, anticoagulants, live bacterial vaccines.
- Pregnancy & Breastfeeding: Use with caution; monitor infant.
- Dosage: Adults: 500 mg bid; Children: 10 mg/kg bid.
- Monitoring Parameters: Renal function, signs of allergic reaction, signs of superinfection (e.g., thrush, C. difficile).
Popular Combinations
Not specifically mentioned in the sources. Combination therapy is generally not required for most infections treatable with cefetamet.
Precautions
- Renal impairment.
- Hepatic dysfunction.
- History of allergic reactions.
- Monitor for superinfections.
- Patients with gastrointestinal issues (e.g., colitis).
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Cefetamet?
A: Adults: 500 mg twice daily; Children: 10 mg/kg twice daily. Dosages may need adjustment in patients with renal impairment or other specific clinical situations.
Q2: What are the common side effects of Cefetamet?
A: The most common side effects are gastrointestinal, including diarrhea, nausea, and vomiting.
Q3: Is Cefetamet safe to use during pregnancy?
A: Limited safety data are available during pregnancy. Use only if the potential benefits outweigh the risks. Discuss with a specialist.
Q4: Can I take Cefetamet while breastfeeding?
A: Small amounts may be present in breast milk. Monitor the infant for adverse effects, such as diarrhea or thrush.
Q5: What infections does Cefetamet treat?
A: Cefetamet is effective against a range of bacterial infections, including respiratory tract infections (bronchitis, pneumonia), urinary tract infections, otitis media, and skin infections.
Q6: What should I do if I miss a dose of Cefetamet?
A: Take the missed dose as soon as you remember. If it is almost time for the next dose, skip the missed dose and continue with your regular schedule. Do not double the dose.
Q7: Are there any drug interactions I should be aware of with Cefetamet?
A: Yes, cefetamet can interact with probenecid, aminoglycosides, anticoagulants, and live bacterial vaccines. Inform your doctor about all medications you are currently taking.
Q8: How is Cefetamet eliminated from the body?
A: Cefetamet is primarily eliminated unchanged through the kidneys.
Q9: What is the mechanism of action of Cefetamet?
A: Cefetamet inhibits bacterial cell wall synthesis by binding to penicillin-binding proteins.
Q10: What precautions are necessary when prescribing Cefetamet?
A: Exercise caution in patients with renal impairment, hepatic dysfunction, or a history of allergic reactions. Monitor for signs of superinfection (e.g., thrush, C. difficile infection).
