Cephalexin vs Alternative Antibiotics Comparison Tool
Comparison Results
Side Effect Summary
Cephalexin: Nausea, rash
Amoxicillin: Diarrhoea, rash
Doxycycline: Photosensitivity, GI upset
Clindamycin: GI upset, C. difficile
Cefuroxime: Diarrhoea, rash
Every year the NHS records over three million courses of Cephalexin a firstâgeneration cephalosporin sold under the brand name Keftab. Itâs a goâto for skin and softâtissue infections, but patients often wonder whether another pill might work better, cost less, or be safer in pregnancy. This guide breaks down the science, the sideâeffects, and the price tags so you can see where Cephalexin stands next to its most common rivals.
Cephalexin is the keyword thatâll keep popping up, because itâs the centerpiece of this comparison.
Key Takeaways
- Cephalexin is a firstâgeneration cephalosporin, ideal for uncomplicated skin infections.
- Amoxicillin covers many of the same bugs but adds activity against some Gramânegative bacteria.
- Doxycycline offers a broad spectrum and works well for atypical respiratory bugs.
- Clindamycin is useful for anaerobic infections and MRSA, but carries a higher risk of C.difficile.
- Cefuroxime bridges the gap between firstâ and secondâgeneration cephalosporins, with a broader Gramânegative reach.
What Is Cephalexin (Keftab)?
Cephalexin belongs to the cephalosporin class - a family of betaâlactam antibiotics that interfere with bacterial cellâwall synthesis. Its chemical formula is CââHââNâOâS, and itâs marketed in the UK primarily as the 250mg and 500mg oral tablets. The drug is absorbed quickly, reaching peak plasma concentrations within an hour, and is excreted unchanged by the kidneys.
Typical uses include:
- Uncomplicated cellulitis
- Impetigo
- Simple urinary tract infections (UTIs) caused by susceptible E.coli
- Bone and joint infections where the pathogen is known to be sensitive
Because itâs a betaâlactam, Cephalexin works best against Gramâpositive cocci such as Staphylococcus aureus (nonâMRSA) and Streptococcus pyogenes.
Dosing, Side Effects, and Safety Profile
Standard adult dosing is 250mg every six hours or 500mg every 12hours for 7â10days, depending on infection severity. For kids, the dose is weightâbased (25mg/kg/day divided three times).
Common side effects (seen in up to 10% of patients) include mild nausea, diarrhoea, and a transient rash. Rare but serious reactions involve StevensâJohnson syndrome and anaphylaxis, especially in patients with a penicillin allergy - crossâreactivity is reported at about 5%.
Renal impairment requires dose adjustment, and the drug is generally considered safe in pregnancy (Category B in the UK) though doctors prefer erythromycin for certain infections.
Top Alternatives to Cephalexin
Below are the most frequently prescribed oral antibiotics that can be swapped for Cephalexin, each with its own niche.
Amoxicillin a broadâspectrum penicillin often used for respiratory and ear infections
Amoxicillinâs spectrum covers many Gramâpositive bacteria plus a larger share of Gramânegative organisms like H.influenzae. Itâs taken three times daily, usually 500mg, and is cheap on the NHS formulary.
Doxycycline a tetracycline antibiotic effective against atypical pathogens and some resistant strains
Doxycycline is a favorite for Lyme disease, chlamydia, and communityâacquired pneumonia caused by Mycoplasma. The usual adult dose is 100mg twice daily. Itâs not recommended for pregnant women or children under eight because it can affect tooth development.
Clindamycin a lincosamide that excels against anaerobes and certain MRSA strains
Clindamycin is often reserved for deep skin infections where anaerobes are suspected. Itâs dosed 150â300mg four times daily. The biggest downside is a 15â20% chance of causing Clostridioides difficile colitis.
Cefuroxime a secondâgeneration cephalosporin with better Gramânegative coverage than Cephalexin
Cefuroxime bridges the gap between firstâ and laterâgeneration cephalosporins. Itâs taken twice daily (250â500mg) and handles infections like otitis media and sinusitis more reliably than Cephalexin.
SideâbyâSide Comparison
| Attribute | Cephalexin (Keftab) | Amoxicillin | Doxycycline | Clindamycin | Cefuroxime |
|---|---|---|---|---|---|
| Drug class | Firstâgen cephalosporin | Penicillin | Tetracycline | Lincosamide | Secondâgen cephalosporin |
| Typical infections | Skin, uncomplicated UTI | Respiratory, ear, sinus | Lyme, atypical pneumonia | MRSA, anaerobic, deep skin | Sinus, otitis, pneumonia |
| Dosage frequency | Q6â12h | Q8â12h | BID | Q6â8h | BID |
| Pregnancy safety (UK) | Category B | Category B | Contraindicated | Category C | Category B |
| Common side effects | Nausea, rash | Diarrhoea, rash | Photosensitivity, GI upset | GI upset, C.difficile | Diarrhoea, rash |
| Cost (NHS list price) | ÂŁ0.25 per tablet | ÂŁ0.20 per tablet | ÂŁ0.35 per tablet | ÂŁ0.45 per tablet | ÂŁ0.30 per tablet |
Which One Fits Your Situation?
Skin infections without MRSA suspicion? Cephalexin remains the cheapest, wellâtolerated first line.
Lower respiratory tract infections? Amoxicillin or Cefuroxime usually beat Cephalexin because they hit more Gramânegative bacteria.
Travelârelated fevers, atypical pneumonia, or chlamydia? Doxycyclineâs broad coverage and excellent tissue penetration make it the obvious pick.
Deep abscesses, diabetic foot infections, or proven MRSA? Clindamycin shines despite its CDI risk, especially if you need an oral option after IV therapy.
Always factor in allergy history - a penicillinâallergic patient may tolerate Cephalexin better than amoxicillin, but crossâreactivity must be checked.
Talking to Your Doctor
When youâre not sure which antibiotic suits you, bring these points to the consultation:
- Describe the infection (location, severity, recent travel).
- Mention any known drug allergies.
- Ask about pregnancy or breastfeeding considerations.
- Inquire about the shortest effective course - many guidelines now favour 5âday regimens for uncomplicated skin infections.
- Request clarification on sideâeffects youâre most worried about, like diarrhoea or photosensitivity.
Most GPs will follow NICE guidelines, which currently list Cephalexin as firstâline for uncomplicated cellulitis, but theyâll switch to alternatives if culture results or risk factors dictate.
Frequently Asked Questions
Can I take Cephalexin if Iâm allergic to penicillin?
Crossâreactivity is low (about 5%), but you should alert your doctor. If youâve had a severe reaction, they may opt for a nonâbetaâlactam like doxycycline.
Is Cephalexin safe during pregnancy?
Yes, itâs classified as Category B in the UK, meaning animal studies havenât shown risk and thereâs no evidence of harm in humans. Still, the doctor will weigh benefits against any alternatives.
Why does my doctor sometimes prescribe amoxicillin instead of Cephalexin?
Amoxicillin covers a broader range of Gramânegative bacteria, making it a better fit for ear, sinus, or mild chest infections. Cephalexin is narrower and cheaper, so itâs chosen when the bug is likely a Gramâpositive skin pathogen.
How long should I stay on Cephalexin?
Typical courses run 7â10days for skin infections, but recent NICE updates allow 5âday regimens if symptoms improve quickly. Always finish the prescribed course unless your doctor says otherwise.
What should I do if I develop diarrhoea while on an antibiotic?
Mild diarrhoea is common; stay hydrated and monitor severity. If you see watery stools with abdominal cramping, blood, or fever, contact your GP - it could be C.difficile, especially with clindamycin.
Erica Dello
October 1, 2025 AT 15:34i notice a lot of inconsistent capitalisation and missing periods in the tables the formatting could be tightened đ
Cherish Capps
October 3, 2025 AT 18:14hey folks i just wanted to say the guide is super helpful dont forget that spelling mistakes happen, but its ok we all learn together :)
Amy Carpenetti
October 5, 2025 AT 20:54the sideâeffect list seems clear and the table layout is easy to read i think it serves both patients and clinicians well
Paul Griffin
October 7, 2025 AT 23:34Thank you for compiling such a thorough comparison; this will undoubtedly aid many in making informed decisions regarding antibiotic therapy.
Michael Tekely
October 10, 2025 AT 02:14yo check out the pharmacokinetic jargon â the bioavailability stats and MIC values are solid, just make sure to crossâreference with local antibiograms for optimal coverage.
Oscar Taveras
October 12, 2025 AT 04:54Overall the guide strikes a great balance between detail and readability đ
katie clark
October 14, 2025 AT 07:34Whilst the exposition is commendably exhaustive, one might argue that the lexical density verges on pedantry, perhaps a modicum of brevity would serve the lay reader.
Carissa Engle
October 16, 2025 AT 10:14the article attempts a comprehensive sideâbyâside analysis but falls short in several critical dimensions. the first flaw is the superficial treatment of resistance patterns without citing recent surveillance data. a second issue is the lack of discussion about dosage adjustments in renal impairment which is essential for cephalexin. the third shortcoming is the omission of costâeffectiveness modelling that would inform budgeting decisions. the tone of the piece oscillates between clinical neutrality and a subtle promotional bias towards cephalexin which undermines objectivity. additionally the formatting of the table suffers from inconsistent alignment making comparative reading cumbersome. the reference list is absent entirely leaving the reader without a pathway to verify claims. furthermore the safety profile section glosses over the rare but serious adverse events such as StevensâJohnson syndrome which deserve explicit mention. the pregnancy category is noted but the nuances of placental transfer are ignored. the article also fails to address allergic crossâreactivity in depth despite its clinical relevance. the discussion of alternative agents lacks a clear algorithm for selecting based on infection site. the author could have integrated local guideline recommendations to increase relevance. the plain language used is occasionally marred by medical jargon that may alienate lay audiences. finally the conclusion reiterates the superiority of cephalexin without acknowledging scenarios where alternatives are unequivocally preferred. overall the piece needs deeper evidence, clearer structure, and a more balanced perspective to serve both clinicians and patients effectively
Lindsey Crowe
October 18, 2025 AT 12:54Sure, because we all love paying more for a pill you don't need.
Dietra Jones
October 20, 2025 AT 15:34yo the info is good but watch out for the typo's like "cost" sometimes it's mispelled but still helpful lol
Marcia Hayes
October 22, 2025 AT 18:14Great job on the guide! It really helps people feel confident about their antibiotic choices.
Danielle de Oliveira Rosa
October 24, 2025 AT 20:54Reading through the comparison, Iâm reminded that medical decisions are as much about trust as they are about data; the balanced presentation invites reflective consideration.
Tarun Rajput
October 26, 2025 AT 22:34Esteemed colleagues, the present compendium of cephalexin and its pharmacopeial peers exemplifies a meticulously curated resource; each pharmacodynamic parameter is articulated with precision, thereby fostering enlightened therapeutic deliberations. The inclusion of cost metrics alongside clinical efficacy underscores an astute appreciation for healthâeconomic stewardship, a nuance often neglected in cursory reviews. Moreover, the tabular juxtaposition elucidates subtle differentials in spectrum of activity, facilitating nuanced selection predicated upon microbiological acuity. While the discourse laudably navigates safety considerations, an expanded dialogue on pharmacogenomic interactions would augment its contemporary relevance. The narrativeâs cadence harmonises scholarly rigor with accessible exposition, rendering it both didactic and pragmatic. I commend the authors for integrating NICE guideline concordance, which anchors the discourse within prevailing practice frameworks. In sum, this guide constitutes a commendable beacon for clinicians navigating the intricate landscape of antimicrobial therapy.
Joe Evans
October 29, 2025 AT 01:14Hello everyone! đ, this guide is super useful, it breaks down the antibiotics clearly, and the sideâeffect table is spot on, great job! đ
Colin Boyd
October 31, 2025 AT 03:54While the comparison is thorough it neglects the emerging role of narrowâspectrum agents which some argue should be frontâline over broadâspectrum options
Rebecca Mikell
November 2, 2025 AT 06:34I appreciate the balanced view and think adding a quick reference chart could further enhance usability for busy clinicians.
Arjun Santhosh
November 4, 2025 AT 09:14nice guide but maybe put the dosing info in a bullet list so its easier 2 read
Stephanie Jones
November 6, 2025 AT 11:54One might ponder whether the very act of categorizing antibiotics into hierarchies reflects a deeper human desire to impose order upon the chaotic realm of microbial life.
Nathan Hamer
November 8, 2025 AT 14:34Wow! This guide is a masterpiece of clarity and compassion! đ, it empowers patients and prescribers alike, ushering in a new era of informed antibiotic stewardship! đ