Keflex: what is cephalexin?

Keflex is a well known and frequently marketed antibiotic in the cephalosporin group. It primarily fights off bacterial infections in the body which frequently affect the respiratory system, the ears, the skin, and the urinary tract. Additionally, it is often given to patients with heart conditions before minor procedures to avoid a bacterial infection known as endocarditis that affects the heart. Keflex is available in the generic form, cephalexin.

Side Effects and Precautions

The most important aspect to consider when dealing with medications are side effects and possible drug interactions or contraindications. Side effects vary depending on the patient. They generally include, but are not limited to:

• Major allergic reaction with symptoms of hives, difficulty breathing, and swelling in the facial area or throat
• Watery or bloody diarrhea
• Sore throat, fever, and headache
• Blistering, peeling skin rash
• Yellow or pale skin
• Dark urine
• Confusion
• Weakness
• Agitation
• Easy bleeding or bruising
• Seizures

Those who have an allergy to penicillin or other cephalosporins should avoid using Keflex. This medication should not be used if there is a past history of kidney or liver disease, GI diseases like colitis, diabetes, or a history of malnutrition. Certain medications when used with Keflex can cause adverse reactions, so patients should provide a full list of home medications to their physicians (including over-the-counter and herbal remedies). Drugs that will affect Keflex are blood thinners like Coumadin, diabetic medications like metformin, and probenecid. It may be beneficial to carry a list of active medications in case of emergency. Check with the prescribing physician before using Keflex if you are on any of these medications or have any conditions that could exacerbate side effects.

What is Keflex used for?

For adults, dosing ranges between one and four grams on a daily basis, but are usually divided into a few doses. Generally speaking, adults are prescribed 250 mg every 6 hours. For certain types of skin infections, a dose of 500 mg is given every 12 hours in patients over the age of 15. More severe infections may require larger doses, which are usually given in a hospital setting. Pediatric patients can safely receive Keflex at a smaller dose of 25 to 50 mg/kg divided doses, usually every 12 hours. Sometimes an infection will require larger doses, but these are monitored very closely by clinicians. Keflex is provided in capsule or liquid form; however, the liquid medication is made with sugar, so this should be avoided or monitored in diabetics.

Keflex should be taken with water and food if possible to avoid an upset stomach. Follow the prescription instructions, as the type of tablet or administration will make a difference in how it’s taken. If a dose is missed at the 6 or 12-hour mark, take it as soon as you remember. If it’s near the time of the next dose, it’s okay to skip - but do not double the dose.