Cephalexin is a cephalosporin-class antibiotic used to treat bacterial infections affecting the respiratory tract, urinary tract, skin, soft tissues, bones, or joints.
This medication should always be taken under medical supervision, as incorrect use can lead to bacterial resistance and reduce its effectiveness over time.
Cephalexin is a prescription-only medication available in pharmacies under the brand name Keflex or as the generic cephalexin monohydrate.
Indications for use
Cephalexin is prescribed to treat bacterial infections such as:
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Tonsillitis or pharyngitis caused by Group A Streptococcus;
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Otitis media;
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Respiratory tract infections, including sinusitis, bronchitis, and mild to moderate pneumonia;
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Urinary tract infections, such as urethritis, cystitis, pyelitis, prostatitis, and pyelonephritis;
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Skin and soft tissue infections, including impetigo, cellulitis, erysipelas, folliculitis, boils, and abscesses;
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Bone infections (osteomyelitis);
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Infected surgical or traumatic wounds.
In some cases, cephalexin may also be prescribed off-label to prevent bacterial infections before dental procedures in people allergic to penicillin.
Cephalexin is a broad-spectrum antibiotic, meaning it acts against many types of bacteria. It works by destroying the infectious agents, which helps improve symptoms and supports recovery.
Dosing instructions
The dosage of cephalexin depends on the type and severity of the infection, as well as the person’s age and overall health.
Cephalexin capsules or tablets (250 mg, 500 mg, or 750 mg)
For streptococcal pharyngitis, skin infections, and uncomplicated cystitis in adults and adolescents aged 15 years or older, the recommended dose is 250 mg to 1 g every 6 hours, for about 7 to 14 days.
For respiratory tract infections caused by Streptococcus pneumoniae or Streptococcus pyogenes (strep A), the usual dose is 500 mg every 6 hours.
More severe infections or those caused by less sensitive bacteria may require higher doses. The maximum recommended daily dose is 4 g.
Cephalexin oral suspension (125 mg/5 mL or 250 mg/5 mL)
For children, the usual daily dose is 25 to 50 mg per kilogram of body weight, divided into several doses every 6 to 12 hours.
For pharyngitis, kidney infections, and skin infections in children over one year old, the total daily dose can be divided and given every 12 hours.
Antibiotics like cephalexin should only be used as prescribed by a healthcare provider, as misuse can harm the body and contribute to antibiotic resistance.
Side effects
The most common side effects of cephalexin include nausea or vomiting, diarrhea, abdominal pain, and hives (urticaria). In some cases, cephalexin can also cause anal or genital itching.
Contraindications for use
Cephalexin should not be used by people who are allergic to cephalosporins or any of its ingredients.
Cephalexin is considered safe for use during pregnancy and breastfeeding when prescribed by a healthcare provider.