Keflex, or cephalexin, is a cephalosporin antibiotic effective against various bacterial infections, but not viral ones like the cold or flu. It kills bacteria by disrupting their cell wall synthesis and is available in oral forms.
Key Uses of Keflex (Cephalexin)
Skin and Soft Tissue Infections
Keflex treats bacterial skin infections from susceptible Staphylococcus aureus and Streptococcus pyogenes. This includes cellulitis, impetigo, erysipelas, and skin abscesses. It's generally not effective against MRSA.
Urinary Tract Infections (UTIs)
Cephalexin is often prescribed for UTIs, particularly uncomplicated cystitis in adults, due to its high urinary excretion. It targets common bacteria like Escherichia coli and Proteus mirabilis. Treatment duration varies, with longer courses or higher doses needed for severe cases.
Respiratory and Ear Infections
Keflex is used for respiratory and ear infections caused by susceptible bacteria, such as otitis media, strep throat (requiring a 10-day course), tonsillitis, and certain types of pneumonia.
Bone and Joint Infections
For bone and joint infections like osteomyelitis caused by susceptible Staphylococcus aureus and Proteus mirabilis, Keflex can be used, often requiring higher doses and longer treatment.
Comparison of Keflex with Other Common Antibiotics
| Feature | Keflex (cephalexin) | Amoxicillin | Penicillin |
|---|---|---|---|
| Class | First-generation cephalosporin | Penicillin | Penicillin |
| Primary Uses | Skin, UTI, respiratory, ear, and bone infections | Ear, sinus, throat, skin, and lower respiratory infections | Strep throat, skin infections, rheumatic fever prevention |
| Dosing Frequency | 2 to 4 times a day | 2 to 3 times a day | 3 to 4 times a day |
| Spectrum | Broad, mainly effective against gram-positive bacteria | Broad, effective against both gram-positive and some gram-negative | Narrow, effective mainly against gram-positive bacteria |
| Allergy Risk | Cross-reactivity with penicillin possible | Higher risk for those with penicillin allergy | Higher risk for those with penicillin allergy |
| Common Side Effects | Nausea, vomiting, diarrhea, dizziness | Nausea, vomiting, diarrhea, rash | Nausea, vomiting, diarrhea |
Important Considerations and Safety Precautions
How to Take Keflex
Complete the full course of medication, even if symptoms improve. This helps prevent infection recurrence and antibiotic resistance. Keflex can be taken with or without food; taking it with food may reduce stomach upset. Store capsules and tablets at room temperature. Liquid suspension needs refrigeration and must be discarded after 14 days.
Alcohol Consumption
While not a major interaction, avoiding alcohol during Keflex treatment is advisable as both can cause nausea and stomach upset. Alcohol can also weaken the immune system.
Adverse Effects
Common side effects include diarrhea, nausea, and abdominal pain. Serious, less common effects are severe allergic reactions and Clostridium difficile diarrhea. Inform your doctor about kidney disease or gastrointestinal issues, as dosage adjustments may be needed.
Conclusion
Keflex is a widely used first-generation cephalosporin antibiotic for various bacterial infections of the skin, urinary tract, ears, and respiratory system. Proper usage as prescribed is crucial for effectiveness and to combat antibiotic resistance. Consult a healthcare provider for any concerns. The FDA provides detailed drug labels for further information.
