What it's for (Indications)
- Treatment of otitis media (ear infection), urinary tract infections, respiratory tract infections (including acute bronchitis, pharyngitis, and pneumonia), and skin and soft tissue infections.
Dosage Information
| Type | Guideline |
|---|---|
| Standard | Take this medicine exactly as prescribed by your doctor. **Oral Suspension:** Shake well before use. Measure the suspension using a calibrated spoon or container; household spoons are inaccurate. Can be consumed with or without meals. **Immediate-Release Tablets/Capsules:** Swallow tablets whole with water; do not crush, break, or chew. Can be consumed with or without meals. **Extended-Release Tablets:** Swallow tablets whole with water; do not cut, crush, or chew. Administer with meals (i.e., within one hour of eating) as absorption is enhanced when taken with food. **Dosage Equivalence:** For specified indications, 500 mg twice daily (BID) of cefaclor extended-release tablets is clinically equivalent to 250 mg three times daily (TID) of cefaclor immediate-release capsules. Note that 500 mg BID of extended-release is NOT equivalent to 500 mg TID of other cefaclor formulations. **Storage:** Store at room temperature away from direct heat and sunlight. Keep out of the reach of children and pets. |
Safety & Warnings
Common Side Effects
- Common side effects include gastrointestinal disturbances such as stomach ache, acid or sour stomach, excessive gas, acid reflux, nausea, vomiting, and diarrhea.
- Other reported effects include dark or clay-colored stools, headache, and rhinitis.
- More severe potential side effects include pseudomembranous colitis, hemolytic anemia, and hypersensitivity reactions.
Serious Warnings
- Black Box Warning: Cefaclor does not carry a specific FDA-mandated Black Box Warning. However, serious warnings and precautions are essential for its safe use. Like nearly all antibacterial agents, cefaclor has been associated with *Clostridioides difficile*-associated diarrhea (CDAD), which can range in severity from mild diarrhea to fatal colitis. CDAD can occur during or even more than two months after the administration of antibacterial agents, requiring careful consideration in patients presenting with diarrhea post-antibiotic treatment. Furthermore, severe hypersensitivity reactions, including anaphylaxis, have been reported with cefaclor therapy. These reactions are more likely to occur in individuals with a history of penicillin hypersensitivity due to potential cross-reactivity between beta-lactam antibiotics. Patients should be meticulously screened for a history of allergies to cephalosporins, penicillins, or other drugs prior to commencing treatment. If an allergic reaction occurs, cefaclor should be discontinued immediately, and appropriate medical management instituted. Prolonged use of cefaclor may also lead to the overgrowth of non-susceptible organisms, necessitating vigilant monitoring for superinfections.
- **Severe Allergic Reactions:** Cefaclor is known to cause severe skin allergic reactions, including rash, fluid-filled blisters (bullae), or lesions.
- Seek immediate medical attention if these signs occur.
- This medicine is not recommended for people who have a history of intolerance to Cefixime or its derivatives.
- Use with caution in patients with a history of penicillin hypersensitivity due to potential cross-reactivity.
- **Hepatic Effects:** May cause liver damage by raising liver enzyme levels.
- Use with caution in patients with pre-existing liver disorders.
- **Gastrointestinal Effects:** May harm beneficial bacteria in the colon or stomach.
- Use with caution in patients with pre-existing gastrointestinal diseases.
- **Renal Impairment:** Use with caution in patients with severe renal (kidney) impairment.
- **Pregnancy:** Pregnant females should consult their doctor before taking this medicine.
- While administration during pregnancy may be considered in some cases, expert medical advice is crucial.
- **Lactation:** Nursing females should consult their doctor before taking this medicine, as the effects on breastfed infants are undetermined.
How it Works (Mechanism of Action)
Cefaclor exerts its bactericidal activity through the inhibition of bacterial cell wall synthesis, a characteristic mechanism shared by all beta-lactam antibiotics. As a second-generation cephalosporin, cefaclor targets and covalently binds to specific enzymes located in the bacterial cytoplasmic membrane, known as penicillin-binding proteins (PBPs). These PBPs are crucial transpeptidases responsible for catalyzing the cross-linking step of peptidoglycan synthesis, which is an essential component of the bacterial cell wall. By forming stable acyl-enzyme intermediates with PBPs, cefaclor irreversibly inactivates these enzymes. This inactivation prevents the proper formation and cross-linking of the peptidoglycan matrix, leading to the production of a defective, osmotically unstable, and structurally weakened cell wall. The compromised integrity of the bacterial cell wall results in increased osmotic pressure within the cell, culminating in cell lysis and subsequent bacterial death. Cefaclor's binding affinity to various PBPs across different bacterial species dictates its spectrum of activity. Its action against both Gram-positive and a wider range of Gram-negative bacteria, including common respiratory pathogens, underscores its clinical utility.