Carry Keflex in its original packaging with the prescription label attached. Keep it in your hand luggage to avoid temperature extremes in the cargo hold. If you are traveling to a country with strict medication import rules, bring a copy of the prescription and a letter from your doctor confirming the necessity of the antibiotic.
Cephalexin is not a controlled substance and does not appear on standard drug-screening panels for employment or sport. Routine tests will not detect it, but disclose any medication use if requested by a governing body.
Both are β-lactam antibiotics, but Keflex belongs to the cephalosporin class, whereas amoxicillin is a penicillin. Cephalexin has stronger activity against many Gram-positive organisms and is less affected by β-lactamase enzymes produced by certain bacteria.
Keflex tablets are typically round, white, and bear the imprint “K 250” or “K 500” indicating the strength of cephalexin contained. The exact imprint may vary by manufacturer.
Keflex is marketed in the UK as a 250 mg or 500 mg oral tablet. Some pharmacies may dispense a generic cephalexin tablet with the same strengths, but the active ingredient and dosing remain identical.
No. In the UK Keflex is a prescription-only medicine (POM). Online pharmacies must require a valid prescription from a registered prescriber before dispensing.
The expiry date is printed on the blister pack and is typically two to three years from the date of manufacture. Do not use tablets after this date, and store them as advised to maintain potency.
Cephalexin absorption is not significantly altered by dietary composition. However, a low-carb diet may affect gastrointestinal tolerance, so monitor for any increased nausea or diarrhoea.
Brand-name Keflex may be priced higher than generic cephalexin tablets of the same strength due to branding and marketing costs. Prices vary between pharmacies; patients can discuss generic options with their prescriber to reduce expense.
Unused or expired tablets should be returned to a pharmacy’s medication-take-back service. Do not flush them down the toilet, as this can contribute to environmental contamination.
Keflex is a brand-name medication that contains the antibiotic cephalexin as its active ingredient. It belongs to the cephalosporin class of antibiotics and is supplied as oral pills in strengths of 250 mg and 500 mg. In the United Kingdom Keflex is a prescription-only medicine (POM) and is regulated by the Medicines and Healthcare products Regulatory Agency (MHRA).
Cephalexin works by interfering with bacterial cell-wall synthesis, making it useful for a range of bacterial infections, particularly those involving the skin, bones, and urinary tract. This article provides an evidence-based overview of Keflex, including how it works, approved uses, safety considerations, dosing guidance, and practical information for patients.
Cephalexin is a β-lactam antibiotic. The β-lactam ring binds to specific penicillin-binding proteins (PBPs) on bacterial cell walls, inhibiting the final stages of peptidoglycan cross-linking. This disruption weakens the wall, leading to osmotic instability and bacterial death-a bactericidal effect.
Because cephalexin targets PBPs that are more prevalent in Gram-positive organisms, it is particularly effective against Staphylococcus aureus (non-MRSA) and Streptococcus species. Its oral formulation is well absorbed from the gastrointestinal tract, achieving peak plasma concentrations within 1 hour (fasted) to 2 hours (with food). The drug is largely excreted unchanged in the urine, which underlies its utility in urinary-tract infections.
Keflex is authorised by the MHRA for the treatment of the following infections in adults:
These indications are based on clinical trial data and the product’s Summary of Product Characteristics (SPC). The antibiotic is selected when the causative bacteria are known or suspected to be sensitive to cephalexin.
Some clinicians prescribe cephalexin off-label for prophylaxis of bacterial infection after certain dental or orthopedic procedures, especially when patients are allergic to penicillins. Limited observational studies suggest that a short course (e.g., 500 mg twice daily for 24 hours) reduces post-operative infection risk in selected patients.
Off-label disclaimer: Use of Keflex for indications not approved by the MHRA must be supervised by a qualified healthcare professional who can assess the benefit-risk balance for the individual patient.
Standard adult dosing (based on the SPC):
For uncomplicated skin infections: 250 mg every 6 hours, or 500 mg every 12 hours, typically for 5 days.
For urinary-tract infections: 500 mg every 6 hours, usually for 7 days.
Renal adjustment (CrCl < 30 mL/min): 250 mg every 12 hours or as advised by the prescriber.
Administration: Swallow the pill whole with a full glass of water. Do not crush or chew unless instructed.
Missed dose: Take the missed dose as soon as remembered unless it is close to the time of the next scheduled dose. Do not double-dose.
Overdose: Symptoms may include nausea, vomiting, diarrhoea, and abdominal pain. Seek urgent medical attention; supportive care is the mainstay.
Discontinuation: Do not stop abruptly if infection is responding; complete the full prescribed course to reduce resistance risk.
This article provides educational information about Keflex (cephalexin) and is not a substitute for professional medical advice. Treatment decisions, including use for unapproved indications, must be made under the guidance of a qualified healthcare provider. The content is intended for informational purposes and does not constitute medical recommendations. Always consult a physician before starting, stopping, or changing any medication regimen.
