Keftab (Cephalexin) vs Common Antibiotic Alternatives - A Practical Comparison

Keftab is a brand‑name tablet formulation of the antibiotic cephalexin, a first‑generation cephalosporin used for a range of mild to moderate bacterial infections. If you’ve been prescribed this pill or are weighing it against other drugs, you’ll want to know when it shines, where it falls short, and which alternatives might suit your situation better. Below you’ll find a concise snapshot, a side‑by‑side comparison, and practical tips for patients and clinicians alike.

Quick Takeaways

• Keftab (cephalexin) works best for skin, bone and uncomplicated urinary‑tract infections.
• Amoxicillin is preferred for ear, sinus and chest infections, especially in children.
• Azithromycin offers a convenient once‑daily dose but may trigger resistance faster.
• Clindamycin is the go‑to for anaerobic infections and patients with penicillin allergy.
• Choosing the right drug hinges on infection type, allergy history, dosing convenience and local resistance patterns.

How Keftab (Cephalexin) Works

Cephalexin belongs to the beta‑lactam antibiotic family that disrupts bacterial cell‑wall synthesis. By binding to penicillin‑binding proteins, it prevents the formation of peptidoglycan cross‑links, causing the bacteria to burst under osmotic pressure. Its spectrum targets many Gram‑positive organisms (like Staphylococcus aureus) and some Gram‑negative species (such as Escherichia coli).

When Keftab Is Typically Prescribed

Clinicians lean on cephalexin for:

• Uncomplicated skin infections (cellulitis, impetigo).
• Bone infections (osteomyelitis) when the pathogen is known to be susceptible.
• Simple urinary‑tract infections caused by susceptible E. coli strains.
• Dental infections and prophylaxis in patients without a severe penicillin allergy.

The standard adult dose ranges from 250mg to 1g every 6‑8hours, adjusted for kidney function. Treatment courses usually last 5-10days, depending on severity.

Common Alternatives and Their Profiles

Below are the most frequently considered substitutes, each introduced with a brief definition and key attributes.

Amoxicillin a broad‑spectrum penicillin

Favoured for ear, sinus, throat and lower‑respiratory infections; typically dosed 500mg three times daily.

Azithromycin a macrolide antibiotic with a long half‑life

Offers a once‑daily regimen (500mg on day1, then 250mg daily for four days); useful for Chlamydia, atypical pneumonia and some STI cases.

Clindamycin a lincosamide targeting anaerobes

Chosen for skin‑soft‑tissue infections involving anaerobes, and as an alternative for patients allergic to penicillins; dose 300mg every 6hours.

Doxycycline a tetracycline‑class broad‑spectrum antibiotic

Effective against a range of tick‑borne diseases, acne, and certain respiratory infections; usually 100mg twice daily.

Trimethoprim‑Sulfamethoxazole (Bactrim) a sulfonamide combo that blocks folate synthesis

Works well for urinary‑tract and some respiratory infections; dosing 160/800mg twice daily.

Side‑by‑Side Comparison

Decision Framework - When to Pick Keftab Over Others

Think of antibiotic choice as a checklist. Consider each factor, then balance the pros and cons.

1. Infection site: Skin and bone infections often respond well to cephalexin; respiratory infections usually need amoxicillin or a macrolide.
2. Allergy profile: Patients with a documented penicillin allergy may tolerate cephalosporins like Keftab, but cross‑reactivity can occur; clindamycin is a safer fallback.
3. Dosing convenience: Azithromycin’s short course wins for adherence, while Keftab requires multiple daily doses, which can be a hurdle for some.
4. Local resistance data: Check your NHS Trust’s antibiogram. If Staphylococcus aureus shows high beta‑lactamase activity, combine cephalexin with a beta‑lactamase inhibitor or choose an alternative.
5. Cost and availability: Generic cephalexin (Keftab) is usually cheaper than newer macrolides, a factor for patients on limited budgets.

Safety, Side‑Effects, and Resistance Management

All antibiotics carry risk. For Keftab, the most common complaints are mild gastrointestinal upset and a transient rash. Rarely, patients develop Clostridioides difficile infection, especially after prolonged courses.

Resistance is a moving target. Cephalosporins like cephalexin are vulnerable to beta‑lactamase enzymes produced by resistant strains. To curb this, clinicians should:

• Limit treatment duration to the shortest effective length.
• Reserve broad‑spectrum agents (azithromycin, clindamycin) for proven need.
• Encourage patients to complete the full course, even if symptoms improve.

Practical Tips for Patients on Keftab

• Take the tablet with a full glass of water; food can reduce stomach irritation.
• If you miss a dose, take it as soon as you remember-unless it’s almost time for the next dose, then skip the missed one.
• Store capsules in a cool, dry place; avoid high humidity bathrooms.
• Report any persistent diarrhea, especially with blood or mucus, to your GP promptly.

Related Concepts and Next Steps

Understanding Keftab fits into a broader conversation about antibiotic stewardship. This includes learning about:

• How penicillin allergies are evaluated and documented.
• The role of pharmacokinetics (absorption, distribution, metabolism, excretion) in dosing decisions.
• When to switch from oral to intravenous therapy for severe infections.

Readers who want to dive deeper might explore topics such as “first‑generation vs. third‑generation cephalosporins,” “managing antibiotic‑associated diarrhea,” or “interpreting microbiology culture results.”

Frequently Asked Questions

Can I take Keftab if I’m allergic to penicillin?

Many people with a penicillin allergy tolerate cephalosporins like cephalexin, but cross‑reaction rates range from 1‑10%. Your doctor should assess the severity of your allergy before prescribing Keftab. If the reaction was anaphylaxis, a non‑beta‑lactam alternative such as clindamycin is safer.

How does Keftab compare to amoxicillin for a sinus infection?

Amoxicillin has stronger activity against the common sinus pathogens Streptococcus pneumoniae and Haemophilus influenzae. Cephalexin can work, but clinicians usually choose amoxicillin first because of its proven efficacy and simpler three‑times‑daily dosing.

What are the most common side‑effects of Keftab?

Patients most often report mild nausea, stomach cramps, or a transient rash. Severe reactions like anaphylaxis are rare but require immediate medical attention.

Is it safe to use Keftab during pregnancy?

Cephalexin is classified as FDA Pregnancy Category B, meaning animal studies have not shown risk and there are no well‑controlled studies in pregnant women. It is generally considered safe, but always discuss any medication with your obstetrician.

Can Keftab cause antibiotic‑associated diarrhea?

Yes. Disruption of normal gut flora can lead to mild diarrhea in up to 15% of patients. If diarrhea becomes severe, watery, or contains blood, seek medical help as it may signal a C. difficile infection.

How should I store Keftab tablets?

Keep them in a dry place at room temperature, away from direct sunlight and moisture. Do not store them in the bathroom cabinet where humidity is high.