- Bacterial Infections 101 Pictures Slideshow
- Take the Tummy Trouble Quiz
- Hepatitis C Slideshow Pictures
- Nitrofurantoin vs. Cephalexin: What's the difference?
- What are nitrofurantoin and cephalexin?
- What are the side effects of nitrofurantoin and cephalexin?
- What is the dosage of nitrofurantoin vs. cephalexin?
- What drugs interact with nitrofurantoin and cephalexin?
- Are nitrofurantoin and cephalexin safe to use while pregnant or breastfeeding?
Nitrofurantoin vs. Cephalexin: What's the difference?
- Nitrofurantoin and cephalexin are antibiotics used to treat urinary tract infections (UTIs).
- Cephalexin is also used to treat middle ear infections (otitis media), tonsillitis, throat infections, laryngitis, bronchitis, pneumonia, skin infections, and bone infections.
- Brand names of nitrofurantoin include Macrobid, Macrodantin, and Furadantin.
- Brand names of cephalexin include Keflex and Daxbia.
- Side effects of nitrofurantoin and cephalexin that are similar include headache, rash, nausea, vomiting, diarrhea, and abdominal pain.
- Side effects of nitrofurantoin that are different from cephalexin include itching, change in urine color, and loss of appetite.
- Side effects of cephalexin that are different from nitrofurantoin include dizziness, fever, abnormal liver tests, and vaginitis.
What are nitrofurantoin and cephalexin?
Nitrofurantoin is an antibiotic used for treating urinary tract infections (UTIs) caused by certain bacteria including E. Coli, Enterobacter cystitis, Klebsiella, Enterococcus, and Staphylococcus aureus. Nitrofurantoin affects the production of bacterial proteins, DNA, and cell walls. Bacteria cannot survive without a cell wall or multiply without DNA. Nitrofurantoin is available in three forms: Furadantin, a microcrystalline form; Macrodantin, a macrocrystalline; and Macrobid, a sustained release form of macrocrystalline used twice daily. The macrocrystalline form is more slowly absorbed than the microcrystalline form and is used in patients who are unable to tolerate the microcrystalline form.
Cephalexin is a cephalosporin antibiotic, 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 others. Common infections cephalexin treats include middle ear infections (otitis media), tonsillitis, throat infections, laryngitis, bronchitis, pneumonia, urinary tract infections (UTIs), skin infections, and bone infections.
What are the side effects of nitrofurantoin and cephalexin?
Common side effects of nitrofurantoin include:
The macrocrystalline form (Macrodantin) appears to cause less stomach upset. Stomach upset also can be minimized by using a lower dose or by taking nitrofurantoin with food or milk.
Possible serious side effects include:
Nitrofurantoin can cause serious lung injury. The reaction can occur within hours of the start of treatment if the patient has previously received nitrofurantoin, or within a few days of starting nitrofurantoin for the first time. Symptoms include:
In other persons, lung injury may occur after approximately a month of treatment. Symptoms include:
- Difficulty breathing
- Rapid breathing
Fortunately, the symptoms usually resolve within a week if the medication is stopped. In other individuals, lung injury may not develop until after several months or years of therapy. Unless it is recognized and treated, this delayed lung injury can result in permanent lung damage that remains even after the drug is stopped.
Nitrofurantoin can also cause damage to the sensory nerves of the arms and legs (peripheral neuropathy), which can cause tingling in the extremities. The condition can become severe and is more likely to occur in people with diabetes, vitamin B deficiency, or general debilitation.
Reduced red blood cell count (anemia) by breaking red blood cells (hemolytic anemia) can occur from nitrofurantoin. This reaction occurs most frequently in persons with a deficiency of an enzyme called glucose--6-phosphate dehydrogenase that is very important to the survival of red blood cells.
Treatment with nitrofurantoin can cause urine to change color to a dark yellow or brown.
The most common side effects of cephalexin are:
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 of nitrofurantoin vs. cephalexin?
- The recommended adult dose for treating urinary tract infections is 50-100 mg 4 times daily (Macrodantin, Furadantin) or 100 mg every 12 hours (Macrobid) for 7 days or for 3 days after obtaining sterile urine.
- Nitrofurantoin can be taken with or without meals. Taking it with meals increases its absorption into the body.
- The suspension can be mixed with water, milk, juice, or infant formula.
- It also is used once a day (or in some children, twice daily) to prevent urinary tract infections.
- It should not be used in persons with poor kidney function.
- 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.
Latest Medications News
Daily Health News
What drugs interact with nitrofurantoin and cephalexin?
- High doses of probenecid (Benemid) or sulfinpyrazone (Anturane) can partially block the kidneys' elimination of nitrofurantoin. This can increase the blood concentrations of nitrofurantoin and the risk of toxicity from nitrofurantoin.
- Concomitant administration of a magnesium trisilicate antacid may decrease the absorption of nitrofurantoin, reducing the effectiveness of nitrofurantoin.
- Nitrofurantoin may reduce the activity of live tuberculosis vaccine (BCG vaccine) and live typhoid vaccine. In laboratory tests, nitrofurantoin reduced the effect of quinolone antibiotics, for example, norfloxacin (Noroxin). Therefore, nitrofurantoin should not be combined with quinolone antibiotics.
Cephalexin may reduce the effect of BCG and typhoid vaccines. Cephalexin should not be combined with BCG or typhoid vaccine unless there are no other options.
Are nitrofurantoin and cephalexin safe to use while pregnant or breastfeeding?
Although there are no adequate studies of nitrofurantoin in pregnant women, many women have safely used it during pregnancy. However, nitrofurantoin should not be used near the time of delivery (38-42 weeks gestation) since it interferes with the immature enzyme systems in the red blood cells of newborns, damaging the cells and resulting in anemia.
There are no adequate and well-controlled studies in pregnant women. Because animal reproduction studies are not always predictive of human response, cephalexin should only be used during pregnancy if clearly needed.
Cephalexin is excreted in breast milk. Cephalexin should be used with caution or stopped when breastfeeding.
Nitrofurantoin and cephalexin are antibiotics used to treat urinary tract infections (UTIs). Cephalexin is also used to treat middle ear infections (otitis media), tonsillitis, throat infections, laryngitis, bronchitis, pneumonia, skin infections, and bone infections.
Multimedia: Slideshows, Images & Quizzes
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...
Bacterial Infections 101: Types, Symptoms, and Treatments
Get more information on bacterial skin infections, which bacteria cause food poisoning, sexually transmitted bacteria, and more....
Skin Infections: Types, Causes, and Symptoms
Viruses, bacteria, and fungi can all cause skin infections. What is scabies? Learn about golden staph infections, cellulitis,...
Urinary Tract Infection (UTI) Symptoms, Diagnosis, Medication
Bladder infections can be painful and often require medical treatment. Get the latest information on urinary tract infections...
What Is a Staph Infection? Causes, Symptoms, Treatments
Do you know what a staph infection is? What about golden staph? Learn about the causes, symptoms, and treatments of staph...
What's Bronchitis? Symptoms and Treatments
Is bronchitis contagious? Learn about bronchitis, an inflammation of the lining of the lungs. Explore bronchitis symptoms,...
What happens within the body when a person develops bronchitis? Take this quick quiz to learn the causes, symptoms, treatments,...
Do I Have Pneumonia Quiz
Pneumonia can be deadly. Take the Pneumonia Quiz on MedicineNet to learn more about this highly contagious, infectious disease.
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...
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,...
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 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...
Related Disease Conditions
Laryngitis is an inflammation of the voice box (vocal cords). The most common cause of acute laryngitis is an infection, which inflames the vocal cords. Symptoms may vary from the degree of laryngitis and age of the person (laryngitis in infants and children is more commonly caused by croup).
Urinary Tract Infection (UTI)
A urinary tract infection (UTI) is an infection of the bladder, kidneys, ureters, or urethra. E. coli, a type of bacteria that lives in the bowel and near the anus, causes most UTIs. UTI symptoms include pain, abdominal pain, mild fever, urinary urgency, and frequency. Treatment involves a course of antibiotics.
Tonsillitis is a contagious infection with symptoms of bad breath, snoring, congestion, headache, hoarseness, laryngitis, and coughing up blood. Tonsillitis can be caused by acute infection of the tonsils, and several types of bacteria or viruses (for example, strep throat or mononucleosis). There are two types of tonsillitis, acute and chronic. Acute tonsillitis lasts from 1-2 weeks while chronic tonsillitis can last from months to years. Treatment of tonsillitis and adenoids include antibiotics, over-the-counter medications, and home remedies to relieve pain and inflammation, for example, saltwater gargle, slippery elm throat lozenges, sipping warm beverages and eating frozen foods (ice cream, popsicles), serrapeptase, papain, and andrographism Some people with chronic tonsillitis may need surgery (tonsillectomy or adenoidectomy).
Staph (Staphylococcus) Infection
Staphylococcus or staph is a group of bacteria that can cause a multitude of diseases. Staph infections can cause illness directly by infection or indirectly by the toxins they produce. Symptoms and signs of a staph infection include redness, swelling, pain, and drainage of pus. Minor skin infections are treated with an antibiotic ointment, while more serious infections are treated with intravenous antibiotics.
Middle Ear Infection (Otitis Media)
A middle ear infection (otitis media) can cause earache, temporary hearing loss, and pus drainage from the ear. It is most common in babies, toddlers, and young children. Learn about causes and treatment.
Is Strep Throat Contagious?
Strep throat is caused by group A streptococcus bacteria. Incubation period for strep throat is 1-5 days after exposure. If strep throat is treated with antibiotics, it is no longer contagious after 24 hours; if it is not treated with antibiotics, it is contagious for 2-3 weeks. Symptoms include fever, sore throat, tonsillitis, white spots or patches on the tonsils, and nausea and vomiting. Diagnosis of strep throat is performed through a rapid strep test.
Is Tonsillitis Contagious?
Tonsillitis is a common infection, especially in kids. Tonsillitis is caused by viruses and bacteria like the flu and herpes simplex virus, and Streptococcus bacteria. These viruses and bacterium are spread person to person. Symptoms of tonsillitis are a yellow or white coating on the tonsils, throat pain, pain when swallowing, and hoarseness.
Pneumonia is inflammation of the lungs caused by fungi, bacteria, or viruses. Symptoms and signs include cough, fever, shortness of breath, and chills. Antibiotics treat pneumonia, and the choice of the antibiotic depends upon the cause of the infection.
Strep throat is a bacterial infection of the throat. Signs and symptoms of strep throat include headache, nausea, vomiting, sore throat, and fever. Strep throat symptoms in infants and children are different than in adults. Strep throat is contagious and is generally passed from person to person. Treatment for strep throat symptoms includes home remedies and OTC medication; however, the only cure for strep throat are antibiotics.
Is Laryngitis Contagious?
Laryngitis is inflammation and swelling of the voice box (larynx). Causes of laryngitis are viral, bacterial, fungal, strenuous singing or talking, chemical irritants, and other underlying medical conditions. Symptoms of laryngitis are hoarseness, a weak or loss of voice, sore throat, dry throat, a tickling sensation in the back of the throat, or irritated or raw throat. Treatment of laryngitis depends upon the cause.
Is a Staph Infection Contagious?
A staph infection is caused by the bacteria Staphylococcus aureus. Staph can cause boils, food poisoning, cellulitis, toxic shock syndrome, MRSA, and various other illnesses and infections. Most staph infections are transmitted from person to person.
Bronchitis is inflammation of the airways in the lung. Acute bronchitis is short in duration (10-20 days) in comparison with chronic bronchitis, which lasts for months to years. Causes of acute bronchitis include viruses and bacteria, which means it can be contagious. Acute bronchitis caused by environmental factors such as pollution or cigarette smoke is not contagious. Common symptoms for acute bronchitis include nasal congestion, cough, headache, sore throat, muscle aches, and fatigue. Acute bronchitis in children also my include runny nose, fever, and chest pain. Treatment for acute bronchitis are OTC pain relievers, cough suppressants (although not recommended in children), and rest. Infrequently antibiotics may be prescribed to treat acute bronchitis.
Urinary Tract Infection in Adults
Second Source article from Government
Is a Urinary Tract Infection (UTI) Contagious?
Bacteria such as E. coli or Pseudomonas can cause a urinary tract infection (UTI). The incubation period for a UTI ranges from three to eight days.
Second Source article from Government
Group A Streptococcal Infections
Second Source article from Government
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, cancer, AIDS), infections (Streptococcus or strep, mononucleosis), allergies, and smoking. Symptoms are a red, swollen throat; fever, and swollen lymph nodes. Treatment for sore throat depends on the cause.
Chronic bronchitis is a cough that occurs daily with production of sputum that lasts for at least 3 months, 2 years in a row. Causes of chronic bronchitis include cigarette smoking, inhaled irritants, and underlying disease processes (such as asthma, or congestive heart failure). Symptoms include cough, shortness of breath, and wheezing. Treatments include bronchodilators and steroids. Complications of chronic bronchitis include COPD and emphysema.
Group A streptococcal infections are caused by group A Streptococcus, a bacteria that causes a variety of health problems, including strep throat, impetigo, cellulitis, erysipelas, and scarlet fever. There are more than 10 million group A strep infections each year.
Urinary Tract Infections in Children
Urinary tract infections (UTIs) are very common in children. Symptoms and signs include fever and abdominal pain. Associated symptoms and signs include flank pain, vomiting, and blood in the urine. Treatment for a UTI involves antibiotic therapy.
Treatment & Diagnosis
- Urinary Tract Infection FAQs
- Pneumonia FAQs
- Strep Streptococcal Throat Infection FAQs
- Ear Infection FAQs
- Bronchitis FAQs
- Is It Easier to Get Staph Infection When You've Had it Before?
- How Do You Get Staph Infection?
- What Causes an Ear Infection?
- How Do You Get an Ear Infection?
- How to Get Rid of a Staph Infection
- Urinary Tract Infection (UTI) Symptoms
- E. coli Infection Facts
- Urinary Tract Infection (UTI) Treatment
Medications & Supplements
- Keflex (cephalexin)
- nitrofurantoin (Macrodantin, Furadantin, Macrobid)
- Cipro, XR (ciprofloxacin) vs. Keflex (cephalexin)
- Nitrofurantoin vs. Amoxicillin
- Cephalexin vs. Amoxicillin
- Nitrofurantoin vs. Ciprofloxacin
- Nitrofurantoin vs. Bactrim
- Levaquin (levofloxacin) vs. Keflex (cephalexin)
- Suprax (cefixime) vs. Rocephin (ceftriaxone)
Subscribe to MedicineNet's General Health Newsletter
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.