Keftab (Cephalexin) — Patient Guide (UK)

Keftab is a brand of cephalexin, an antibiotic in the cephalosporin family. It is used to treat certain bacterial infections, most commonly skin and soft tissue infections and infections affecting the ear, throat, urinary tract, and respiratory system.

This guide explains how Keftab works, how it is used, key safety information, and practical tips to help you get the best benefit from your treatment.

Basic product information

• Medicinal ingredient: Cephalexin
• Medicine type: Antibiotic (beta-lactam; cephalosporin)
• Common strength: Available in various oral tablet formulations depending on the specific product pack
• How it’s taken: By mouth (tablets/capsules/other oral forms depending on the pack)
• Who it’s for: Adults and children (dose depends on age, weight, and infection type)

How Keftab works (mechanism of action)

Cephalexin works by attacking the bacteria’s ability to build and repair their cell walls. It binds to specific proteins involved in cell wall construction, leading to weakening of the bacterial cell wall and ultimately bacterial death.

Keftab is designed to target bacteria. It will not treat viral illnesses such as the common cold or flu.

Pharmacokinetics (how your body handles cephalexin)

Pharmacokinetics describe how a medicine is absorbed, distributed, metabolised, and eliminated.

• Absorption: Cephalexin is absorbed after oral dosing. Taking it regularly helps maintain effective antibiotic levels.
• Distribution: It distributes through body tissues and fluids, including sites relevant to common infections.
• Metabolism: Cephalexin is not extensively metabolised.
• Elimination: Most of the dose is removed from the body via the kidneys. Dose adjustments may be needed in reduced kidney function.
• Timing profile: Because levels can fall between doses, cephalexin is often taken in multiple daily doses to keep antibacterial activity steady.

Typical uses and indications (what Keftab is for)

Keftab is used for infections caused by bacteria sensitive to cephalexin. Your clinician will choose it based on the likely bacteria, the infection site, severity, and your personal history (including allergies).

Common infection types

• Skin and soft tissue infections (for example, impetigo, infected wounds, cellulitis caused by susceptible bacteria)
• Ear, nose, and throat infections (for example, certain cases of tonsillitis or otitis media when appropriate)
• Urinary tract infections (UTIs) caused by susceptible organisms
• Respiratory tract infections (for example, some cases of bronchitis or pneumonia when due to susceptible bacteria)

Not all infections will be suitable for cephalexin. Some infections require different antibiotics or additional investigations (such as swabs or urine testing).

When to take Keftab (timing and how to use it)

Antibiotics work best when taken at consistent times. Follow the dosing schedule provided with your medicine pack or by your healthcare professional. If you are unsure, ask a pharmacist for advice.

General timing guidance

• Try to space doses evenly across the day.
• Finish the full course unless advised otherwise by a healthcare professional.
• Don’t double up if you miss a dose—see “Missed doses” in the FAQ.

How long does it take to start working?

Some improvement is often seen within 48–72 hours of starting treatment. However, this depends on the infection type and your immune response.

If your symptoms are worsening, or you are not improving after a few days, contact a healthcare professional for review.

Food interactions (can you take it with meals?)

Cephalexin can generally be taken with or without food. Taking it with food may reduce the chance of stomach upset for some people.

If your pack instructions specify “with meals” or “on an empty stomach”, follow those directions carefully.

Alcohol and medicine interactions

Alcohol

There is no universally required restriction on alcohol for cephalexin in the same way as some other antibiotic classes. However, drinking alcohol while you’re unwell may make symptoms feel worse and can impair hydration and recovery.

To support recovery, it’s sensible to avoid heavy drinking and drink plenty of fluids. If you’re unsure, ask your pharmacist.

Interactions with other medicines

Cephalexin has interactions, but many people take it safely alongside their other routine medicines. Always tell a healthcare professional or pharmacist about your full list of medicines, including over-the-counter products and herbal remedies.

Medicines that may be relevant

• Probenecid may affect how antibiotics are cleared from the body.
• Other antibiotics or antimicrobial combinations may be chosen only if clinically appropriate.
• Oral anticoagulants (blood thinners) (such as warfarin): antibiotics can sometimes change bleeding risk by altering gut bacteria and vitamin production. Monitoring may be needed.
• Kidney function-related medicines: because cephalexin is cleared via the kidneys, kidney-related medicines may influence risk.

This is not a complete list. For personal safety, discuss interactions with a pharmacist—especially if you take regular medications.

Dosing (how much to take)

Dosing varies by age, weight, infection type, severity, and kidney function. Always use the dose stated on your medicine pack or provided by a healthcare professional.

Typical dosing patterns (general)

• Cephalexin is commonly taken in divided doses over the day (for example, two to four times daily depending on the prescribed regimen).
• Duration of treatment depends on infection type and response—some infections require shorter courses, while others may need longer.

Important: If your pack or clinician provided a specific regimen, follow it exactly. Do not change the dose or stop early without advice, even if you feel better.

Children and babies

In children, dosing is often based on body weight and age. For children who cannot swallow tablets, an appropriate oral formulation may be used (e.g., suspensions, if available). Use only the formulation and strength intended for paediatric use.

Kidney problems

Because cephalexin is excreted mainly through the kidneys, people with reduced kidney function may need dose adjustments. Tell your clinician if you have chronic kidney disease or a history of kidney problems.

Safety profile (who should be careful and common side effects)

Like all medicines, Keftab (cephalexin) can cause side effects. Many are mild and improve as treatment ends.

Common side effects

• Diarrhoea
• Nausea or stomach discomfort
• Vomiting
• Headache
• Skin rash (may be mild, but a rash can sometimes signal allergy)

Serious allergic reactions (seek urgent help)

Stop taking cephalexin and seek urgent medical advice if you develop signs of a serious allergy, such as:

• Swelling of the face, lips, tongue, or throat
• Difficulty breathing or wheezing
• Severe skin rash, blistering, or peeling skin
• Fainting or feeling severely unwell

Other important warnings

• Severe or persistent diarrhoea: If you develop watery diarrhoea, fever, abdominal cramps, or blood/mucus in your stool, contact a healthcare professional promptly. Antibiotics can, in some cases, contribute to gut infections.
• History of allergy to cephalosporins or penicillins: Discuss this before starting cephalexin. Cross-reactions can occur in some people.
• Blood clotting issues: If you take warfarin or similar medicines, you may need closer monitoring.

Driving and operating machinery

Cephalexin is not usually associated with dizziness, but individual reactions vary. If you feel unwell or dizzy, avoid driving or hazardous activities until you feel better.

Practical use tips (get the best from your course)

• Set reminders: Use phone alarms or a medication organiser to keep doses on time.
• Take with a full glass of water: This can help reduce stomach upset and supports swallowing.
• Don’t share antibiotics: Even similar infections may be caused by different bacteria.
• Keep the course consistent: Avoid skipping doses unless advised.
• Hydrate: Drinking adequate fluids supports recovery, especially with fever or diarrhoea.
• Probiotics? If you choose to use probiotics or fermented products, they may help some people maintain gut comfort during antibiotics, but evidence varies—ask a pharmacist if you’re unsure, especially if you’re immunocompromised.

Missed dose guidance (general)

If you miss a dose, take it as soon as you remember unless it is close to your next dose. In that case, skip the missed dose and continue as normal. Do not take a double dose.

Alternative options (other ways antibiotics may be chosen)

The “best” antibiotic depends on the infection type and the bacteria likely to be involved. Alternatives to cephalexin may include other antibiotics (selected by a clinician) such as:

• Penicillin-based antibiotics (if suitable and not contraindicated)
• Amoxicillin or co-amoxiclav in certain throat/ear or skin infections
• Macrolides (such as clarithromycin/azithromycin) for people who cannot take beta-lactams, depending on local guidance and resistance patterns
• Nitrofurantoin, trimethoprim, fosfomycin for specific UTIs (depending on suitability and resistance)

Your pharmacist can help explain why an alternative might or might not be appropriate for your situation. Don’t start or switch antibiotics without advice.

UK market and legal context (important for UK shoppers)

In the United Kingdom, antibiotics such as cephalexin are regulated medicines. They are supplied under UK pharmaceutical and medicines governance frameworks to support safe use and antimicrobial stewardship.

Availability can vary by formulation and pack size. If you’re browsing online, always ensure the product matches the exact active ingredient and strength listed, and that it’s intended for your age group and use case.

Antimicrobial resistance is a major public health concern. Using antibiotics only when needed, and taking them correctly, helps preserve their effectiveness.

Recent guidance and antimicrobial stewardship (UK focus)

UK recommendations emphasise:

• Right antibiotic, right dose, right duration for the suspected or confirmed bacteria.
• Avoiding antibiotics for viral infections (like colds and flu).
• Reviewing treatment if symptoms fail to improve within a few days.
• Taking courses as directed to reduce relapse and resistance.

Guidance may vary depending on the infection site and local antimicrobial resistance patterns. If symptoms do not improve or worsen, seek clinical review.

Delivery and availability (UK online pharmacy)

Keftab availability may differ by strength and pack size. Many online pharmacies operate delivery services across the UK, with options such as standard and express delivery depending on your location and order type.

What to expect when ordering online

• Order processing time: orders are usually checked and prepared before dispatch.
• Packaging: medicines are shipped in appropriate protective packaging.
• Delivery updates: tracking information may be provided for some delivery services.
• Availability: if an item is temporarily out of stock, the pharmacy may offer an alternative equivalent product or notify you.

Delivery times vary by supplier, courier, and location. Check the website’s delivery information at checkout for the most accurate timeframe.

Frequently Asked Questions (FAQ)

Is Keftab the same as cephalexin?

Yes. Keftab is a brand name that contains cephalexin, the active antibiotic ingredient.

What should I do if I feel worse after starting Keftab?

Some symptoms may take time to settle, but worsening symptoms can be a sign the infection is not responding or needs reassessment. Contact a healthcare professional promptly, especially if you develop fever, worsening pain, spreading redness, breathing difficulties, or severe diarrhoea.

Can I stop early if I feel better?

It’s usually important to complete the full course as advised. Stopping early can increase the risk of infection returning and may contribute to resistance.

Can I take Keftab on an empty stomach?

Many people can take cephalexin with or without food. If you get stomach upset, taking it with food may help. Follow any specific instructions on your pack.

Are there dietary restrictions?

No specific diet is required. You can continue normal meals unless you’re advised otherwise due to another condition.

Will Keftab interact with birth control?

Antibiotics like cephalexin are not commonly associated with reducing the effectiveness of hormonal contraceptives. However, if you have vomiting or severe diarrhoea, absorption may be affected—follow contraceptive guidance and speak to a pharmacist if unsure.

What if I miss a dose?

Take it as soon as you remember unless it’s close to your next planned dose. Skip the missed dose if your next dose is near, then continue your schedule. Do not take a double dose.

Who should not take cephalexin?

People with a known allergy to cephalexin or other cephalosporin antibiotics should avoid it. Those with a history of serious allergy to beta-lactam antibiotics should discuss suitability with a clinician or pharmacist before use.

How should I store Keftab?

Store at the temperature stated on the packaging and keep out of the sight and reach of children. Do not use after the expiry date. Keep tablets in their original container or pack as instructed.

Is it safe to take with other medicines I already use?

Many combinations are possible, but interactions can occur. Provide your full list of medicines (including OTC products) to a pharmacist if you’re unsure—especially if you take blood thinners or have kidney problems.

Quick reference table (summary)

When to seek medical advice immediately

Contact urgent medical care if you experience:

• Difficulty breathing, facial/lip/tongue swelling, or fainting
• Severe or rapidly spreading rash, blistering, or peeling skin
• Severe diarrhoea (especially with fever or blood/mucus)
• Severe worsening of the infection symptoms

For persistent symptoms, concerns about side effects, or questions about suitability, speak to a pharmacist or clinician.