Cephalexin is a widely prescribed antibiotic used to treat a variety of bacterial infections. Understanding what cephalexin is, how it works, and the correct dosage is crucial for effective treatment. This article provides a comprehensive overview of cephalexin, its uses, dosage guidelines, and important considerations.
Understanding Cephalexin: A Broad-Spectrum Antibiotic
Cephalexin belongs to a class of antibiotics known as cephalosporins. These antibiotics are broad-spectrum, meaning they are effective against a wide range of bacteria. Cephalexin works by interfering with the bacteria’s ability to form cell walls. Bacteria need cell walls to survive; by disrupting this process, cephalexin effectively kills the bacteria or stops them from growing.
It’s important to note that cephalexin is only effective against bacterial infections. It will not work against viral infections such as the common cold or flu. Using antibiotics unnecessarily can contribute to antibiotic resistance, making them less effective in the future.
Cephalexin is available under various brand names, with Keflex being one of the most recognized. It is typically administered orally in capsule form. Common strengths include 250 mg, 500 mg, and 750 mg capsules.
What is Cephalexin Used For? Treating Bacterial Infections
Cephalexin is prescribed to treat a range of bacterial infections throughout the body. Its effectiveness against a broad spectrum of bacteria makes it a versatile treatment option. Common infections treated with cephalexin include:
- Respiratory Tract Infections: These include infections of the lungs and airways, such as bronchitis and pneumonia caused by susceptible bacteria.
- Otitis Media (Middle Ear Infections): Cephalexin can be used to treat bacterial infections of the middle ear, particularly common in children.
- Skin and Skin Structure Infections: This encompasses various skin infections like cellulitis, impetigo, and infected wounds.
- Bone Infections: Infections affecting the bones, known as osteomyelitis, can sometimes be treated with cephalexin.
- Genitourinary (Urinary Tract) Infections (UTIs): Cephalexin is effective against many bacterial UTIs, including bladder infections.
It is crucial to use cephalexin only for infections diagnosed as bacterial by a healthcare professional. Self-treating with antibiotics can be harmful and may not be effective against the specific infection you have.
Cephalexin Dosage: Guidelines for Adults and Children
The correct dosage of cephalexin varies depending on several factors, including the type and severity of the infection, the patient’s age, kidney function, and overall health. It is essential to strictly follow your doctor’s prescription and dosage instructions. Never adjust the dosage yourself.
The following dosage information provides general guidelines and should not replace professional medical advice.
Dosage for Respiratory Tract, Otitis Media, Skin, Bone, and Genitourinary Infections:
For many infections, the typical adult and adolescent dosage (ages 15-64 years) is as follows:
- Mild to Moderate Infections: 250 mg every 6 hours, or 500 mg every 12 hours.
- Severe Infections: Your doctor may increase the dose, up to 4 grams per day, divided into multiple doses.
Child Dosage (ages 1-14 years):
Dosage for children is based on body weight and the severity of the infection.
- Mild to Moderate Infections: 25–50 mg/kg of body weight per day, divided into multiple doses.
- Severe Infections (Otitis Media): 75–100 mg/kg of body weight per day, divided into doses every 6 hours. For other severe infections, the doctor may double the standard dose.
Important Notes for Children:
- Cephalexin is not typically studied for use in children younger than 1 year for these conditions. Consult your pediatrician for appropriate treatment options for infants.
- For otitis media specifically, the higher dosage range (75-100 mg/kg/day) is often recommended.
Special Dosage Considerations:
- Older Adults (65 years and older): Kidney function may be reduced in older adults, potentially leading to slower drug processing. Doctors may prescribe a lower starting dose to minimize the risk of side effects.
- Kidney Problems: Patients with impaired kidney function may require dosage adjustments to prevent drug buildup in the body. Dosage adjustments are based on creatinine clearance (CrCL) levels:
- CrCL 30–59 mL/min: Maximum daily dose should not exceed 1 gram.
- CrCL 15–29 mL/min: 250 mg every 8 or 12 hours.
- CrCL 5–14 mL/min: 250 mg every 24 hours.
- CrCL 1–4 mL/min: 250 mg every 48 or 60 hours.
Always inform your doctor about any kidney problems or other medical conditions you have so they can determine the safest and most effective cephalexin dosage for you.
Cephalexin Side Effects: What to Watch For
Like all medications, cephalexin can cause side effects. Most side effects are mild and temporary, but some can be more serious.
Common Side Effects:
- Diarrhea
- Nausea
- Vomiting
- Stomach pain
These side effects are usually mild and resolve on their own. Taking cephalexin with food may help reduce stomach upset.
Serious Side Effects (Seek Medical Attention Immediately):
- Severe Allergic Reactions: Symptoms include rash, hives, itching, swelling (especially of the face, tongue, or throat), severe dizziness, and trouble breathing. Anaphylaxis is a life-threatening allergic reaction requiring immediate medical help.
- Severe Diarrhea (Clostridium difficile-associated diarrhea – CDAD): This can cause watery or bloody stools, stomach pain, and fever. CDAD can occur during or even several weeks after antibiotic treatment.
- Seizures: In rare cases, cephalexin may increase the risk of seizures, especially in individuals with epilepsy or kidney problems.
This is not a complete list of side effects. If you experience any unusual symptoms while taking cephalexin, contact your doctor promptly.
Conclusion: Using Cephalexin Safely and Effectively
Cephalexin is a valuable antibiotic for treating various bacterial infections. Understanding what cephalexin is, its appropriate uses, and correct dosage is essential for successful treatment and minimizing potential risks. Always use cephalexin as prescribed by your doctor, complete the full course of treatment, and be aware of potential side effects. If you have any questions or concerns about cephalexin, consult your healthcare provider for personalized guidance.
