- Bacterial Infections 101 Pictures Slideshow
- Take the Tummy Trouble Quiz
- Hepatitis C Slideshow Pictures
- What is cephalexin? How does it work (mechanism of action)?
- What are the uses for cephalexin?
- What are the side effects of cephalexin?
- What is the dosage for cephalexin?
- Which drugs or supplements interact with cephalexin?
- Is cephalexin safe to take if I'm pregnant or breastfeeding?
- What else should I know about cephalexin?
What is cephalexin? How does it work (mechanism of action)?
Cephalexin belongs to a class of antibiotics called cephalosporins. They are similar to penicillin in action and side effects. They stop or slow the growth of bacterial cells by preventing bacteria from forming the cell wall that surrounds each cell. The cell wall protects bacteria from the external environment and keeps the contents of the cell together, and without a cell wall, bacteria are not able to survive. Bacteria that are susceptible to cephalexin include Staphylococcus aureus, Streptococcus pneumoniae, Haemophilus influenzae, E. coli and several others. Cephalexin was approved by the FDA in January 1971.
What are the uses for cephalexin?
Cephalexin is used to treat infections caused by bacteria that are susceptible to the effects of cephalexin. Common infections that cephalexin treats include:
What are the side effects of cephalexin?
The most common side effects of cephalexin are:
- abdominal pain,
- skin rash,
- abnormal liver tests, and
Individuals who are allergic to penicillin may also be allergic to cephalexin. Serious but rare reactions include seizures, severe allergic reactions (anaphylaxis), and low platelet or red blood cell count.
Cephalexin, like almost all antibiotics, may cause mild or severe cases of pseudomembranous colitis, a mild to severe inflammation of the colon. Antibiotics, including cephalexin alter the types of bacteria in the colon and permit overgrowth of a bacterium called Clostridium difficile. Studies indicate that toxins produced by Clostridium difficile are a primary cause of pseudomembranous colitis.
What is the dosage for cephalexin?
- The dose of cephalexin for adults is 1 to 4 grams in divided doses.
- The usual adult dose is 250 mg every 6 hours.
- Some infections may be treated with 500 mg every 12 hours.
- Children are treated with 25-100 mg/kg/day in divided doses.
- The dosing interval may be every 6 or 12 hours depending on the type and seriousness of the infection.
Which drugs or supplements interact with cephalexin?
Is cephalexin safe to take if I'm pregnant or breastfeeding?
What else should I know about cephalexin?
- Cephalexin is available in generic form. You need a prescription to obtain cephalexin.
- Keflex is the brand name available for cephalexin in the US.
- Cephalexin is available as:
- Tablets of 250 and 500 mg.
- Capsules: 250, 500 and 750 mg.
- Powder for Suspension: 125 and 250 mg/5 ml.
- Cephalexin tablets and capsules should be stored at room temperature, 15 C to 30 C (59 F to 86 F). Suspensions should be refrigerated and discarded 14 days after they have been prepared from the powder.
Quick GuideSymptoms of Mono: Infectious Mononucleosis Treatment
Cephalexin (Keflex) is a prescription antibiotic used for treating middle ear infections (otitis media), tonsillitis, laryngitis, pneumonia, urinary tract infections (UTIs), skin infections, bone infections, throat infections, bronchitis, and bone infections.
Side effects, drug interactions, storage, dosage, and pregnancy safety information should be reviewed prior to taking any medication.
Multimedia: Slideshows, Images & Quizzes
Ear Infection Quiz: Test Your Medical IQ
Is it possible to prevent ear infections? Take the Ear Infection (Otitis Media) Quiz to learn the risks, causes, symptoms and...
Do I Have Pneumonia? Symptoms & Signs
Pneumonia can be deadly. Take the Pneumonia Quiz on MedicineNet to learn more about this highly contagious, infectious disease....
Strep (Streptococcal) Throat Infection Quiz: Test Your Infectious Disease IQ
Take the Strep (Streptococcal) Throat Infection Quiz to learn about causes, symptoms, treatments, prevention methods, diagnosis,...
What happens within the body when a person develops bronchitis? Take this quick quiz to learn the causes, symptoms, treatments,...
Ear Health Quiz
How loud is too loud? Take this quiz to learn about your ears, how they function, and how to keep them healthy....
Urinary Tract Infection Quiz
How would you know if you had urinary tract infection (UTI)? Take the Urinary Tract Infection in Adult Quiz to learn the causes,...
Picture of Bronchitis
Acute bronchitis usually comes on quickly and gets better after several weeks. See a picture of Acute Bronchitis and learn more...
Picture of Strep Throat
Strep infection often produces a distinct pattern of white patches in the throat and on the tonsils, as well as red swollen...
Picture of Tonsil Stones
Tonsil stones (also called tonsilloliths) form when bacteria and mucus get trapped and calcify in your tonsils' nooks and...
Picture of Tonsils
The tonsils (palatine tonsils) are a pair of soft tissue masses located at the rear of the throat (pharynx). See a picture of the...
Boils: Causes, Symptoms, and Home Remedies
What causes boils? Learn home remedies for boils on the skin, how to get rid of boils, as well as the causes, symptoms, and types...
Diverticulitis (Diverticulosis) Symptoms, Diet, Treatment
Diverticulitis (diverticulosis) is a condition in which the diverticulum or diverticula rupture in the colon causing infection....
Urinary Tract Infection (UTI) Symptoms, Diagnosis, Medication
Understand urinary tract infection (UTI) through pictures. Our experts describe urinary tract infection symptoms like pelvic...
Sore Throat or Strep Throat? How to Tell the Difference
Explore the types and causes of a sore throat through pictures, including strep throat, and learn how to find relief from that...
Ear Infection Symptoms, Causes, and Treatment
Learn about the causes and symptoms of ear infections and how they are diagnosed and treated. Read about treatments such as ear...
Bronchitis Symptoms and Treatments
Is bronchitis contagious? Learn about bronchitis, an inflammation of the lining of the lungs. Bronchitis can be aggravated from...
Early Signs & Symptoms of Pregnancy
Read about early signs and symptoms of pregnancy such as nausea and vomiting (morning sickness), bloating, tender breasts, and...
Sinus Infection (Sinusitis) Symptoms & Treatment
Sinus infection (sinusitis) symptoms can include headaches, a sore throat, and toothaches. Chronic sinusitis may be caused by...
Bladder Infections: UTI Causes, Symptoms, Treatments
Urinary tract infections (UTI), including bladder infections, affect women and men, causing UTI symptoms like kidney infection....
Bacterial Infections 101: Types, Symptoms, and Treatments
Learn more about bacteria and the most common bacterial infections. Get more information on bacterial skin infections, which...
Common Respiratory Illnesses
Is your cough caused by a cold, flu, pneumonia or something else? Learn causes of respiratory infection like bronchitis,...
Related Disease Conditions
Tonsillitis (Adnoiditis, Symptoms, Home Treatment, Pictures, Causes)
Tonsillitis is a contagious infection with symptoms of bad breath, snoring, congestion, headache, hoarseness, laryngitis,...
Boils (Skin Abscesses)
A boil is a skin abscess, a collection of pus localized deep in the skin. There are several different types of boils. Among them...
Diverticulitis (Diverticulosis, Diverticular Disease)
Most people with diverticulosis have few if any symptoms at all. When people do experience signs and symptoms of diverticulosis...
Pneumonia is inflammation of the lungs caused by fungi, bacteria, or viruses. Symptoms and signs include cough, fever, shortness...
Sore throat (throat pain) usually is described as pain or discomfort in the throat area. A sore throat may be caused...
Strep Throat (Treatment, Causes, Home Remedies)
Strep throat is a bacterial infection of the throat. Signs and symptoms of strep throat include headache, nausea,...
Urinary Tract Infections (UTIs)
A urinary tract infection (UTI) is an infection of the bladder, kidneys, ureters, or urethra. E. coli, a type of bacteria that...
Group B Strep
Group B strep are bacteria called Streptococcus agalactiae that may sometimes cause infections both in a pregnant woman and her...
Ear Infection (Otitis Media)
Middle ear infection or inflammation (otitis media) is inflammation of the middle ear. There are two forms of this type of ear...
Impetigo is a contagious skin infection caused by staph and strep bacteria. There are two types of impetigo: nonbullous and...
An abscessed tooth is an infection within a tooth that has spread to the root. Symptoms of an abscessed tooth may include pain,...
Bronchitis (Acute) Symptoms, Causes, Treatment Remedies, and Cures
Bronchitis is inflammation of the airways in the lung. Acute bronchitis is is short in duration (10 to 20 days) in comparison...
Group A streptococcal infections are caused by group A streptococcus, a bacteria that causes a variety of health problems,...
Emphysema, Chronic Bronchitis, and Colds
If you have a COPD such as emphysema, avoiding chronic bronchitis and colds is important to avoid a more severe respiratory...
Folliculitis is a skin condition that causes small red bumps to form around the hair follicles. Skin bacteria such as...
Laryngitis is an inflammation of the voice box (vocal cords). The most common cause of acute laryngitis is infection, which...
Chronic Bronchitis (Symptoms, Causes, Treatment, Remedies)
Chronic bronchitis is a cough that occurs daily with production of sputum that lasts for at least three months, two years in a...
Ingrown hairs may be caused by improper shaving, waxing, or blockage of the hair follicle. Symptoms and signs of ingrown hairs...
Urinary Tract Infections in Children
Urinary tract infections (UTIs) are very common in children. Symptoms and signs include fever and abdominal pain. Associated...
Scarlet Fever (Scarlatina)
Scarlet fever, a bacterial infection caused by group A Streptococcus bacteria, causes symptoms and signs such as fever, rash with...
Sore Throat Home Remedies (Soothe, Pain Relief)
Natural and home remedies for sore throat symptoms and pain relief include essential oils, licorice gargles, slippery elm...
Is Strep Throat Contagious?
Strep throat is caused by group A streptococcus bacterium. Symptoms of strep throat include sore throat, white patches or spots...
Is Tonsillitis Contagious?
Tonsillitis is a common infection, especially in kids. Tonsillitis is caused by viruses and bacteria like the flu and herpes...
Are Boils Contagious?
A boil is a hair follicle that has been infected with bacteria. Boils can spread if a person's boil touches another person....
Is Sore Throat (Pharyngitis) Contagious?
The medical term for a sore throat is pharyngitis. There are many causes of a sore throat such as medications, diseases (GERD,...
Bronchiolitis is an illness caused by a variety of viruses that is most common during the winter season. Bronchiolitis symptoms...
19 Tips on How to Stop a Cough
Coughing is a reflex that helps a person clear their airways of irritants. There are many causes of an excessive or severe...
Ear Infection Home Treatment
Infections of the outer, middle, and inner ear usually are caused by viruses. Most outer (swimmer's ear) and middle ear...
Inner Ear Infection (Symptoms, Signs, Treatments, Home Remedies)
An inner ear infection or otitis interna is caused by viruses or bacteria and can occur in both adults and children. An inner...
Treatment & Diagnosis
- Urinary Tract Infection FAQs
- Pneumonia FAQs
- Strep Streptococcal Throat Infection FAQs
- Ear Infection FAQs
- Bronchitis FAQs
- Ear Health FAQs
- Gonorrhea Treatment Recommendations Update
- Medication Disposal
- Dangers of Mixing Medications
- How To Reduce Your Medication Costs
- Pharmacy Visit, How To Get The Most Out of Your Visit
- Indications for Drugs: Approved vs. Non-approved
- Strep Throat Diagnosis & Treatment
- Drugs: Buying Prescription Drugs Online Safely
- Drugs: The Most Common Medication Errors
- Kidney Infections During Pregnancy
- Antibiotics 101
- Generic Drugs, Are They as Good as Brand-Names?
Medications & Supplements
Prevention & Wellness
Infectious Disease Resources
Health Solutions From Our Sponsors
Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.