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Cephalosporins are medicines that kill bacteria or prevent their growth.


Cephalosporins are used to treat infections in different parts of the body—the ears, nose, throat, lungs, sinuses, and skin, for example. Physicians may prescribe these drugs to treat pneumonia, strep throat, staph infections, tonsillitis, bronchitis, and gonorrhea. These drugs will not work for colds, flu, and other infections caused by viruses.
Cephalosporins are a newer class of antibiotics and often are seen as an alternative to penicillin for many patients. Clinical studies continue to compare this class of antibiotics to penicillin in combating various infections. For example, a 2004 study showed that cephalosporins are three times more effective than penicillin for treating bacterial throat infections, such as strep throat, in children. The authors recommended cephalosporin drugs as the first choices for pediatricians.


Examples of cephalosporins are cefaclor (Ceclor), cefadroxil (Duricef), cefazolin (Ancef, Kefzol, Zolicef), cefixime, (Suprax), cefoxitin (Mefoxin), cefprozil (Cefzil), ceftazidime (Ceptaz, Fortaz, Tazicef, Tazideme), cefuroxime (Ceftin) and cephalexin (Keflex). These medicines are available only with a physician's prescription. They are sold in tablet, capsule, liquid, and injectable forms.

Recommended dosage

The recommended dosage depends on the type of cephalosporin. The physician who prescribed the drug or the pharmacist who filled the prescription can recommend the correct dosage.
Cephalosporins always should be taken exactly as directed by the physician. Patients never should take larger, smaller, more frequent, or less frequent doses. The drug should be taken for exactly as long as directed, no more and no less. Patients should not save some doses of the drug to take for future infections. The medicine may not be right for other kinds of infections, even if the symptoms are the same. In addition, patients should take all of the medicine to treat the infection for which it was prescribed. The infection may not clear up completely if too little medicine is taken. Taking this medicine for too long, on the other hand, may open the door to new infections that do not respond to the drug.
Some cephalosporins work best when taken on an empty stomach. Others should be taken after meals. The physician who prescribed the medicine or the pharmacist who filled the prescription can provide instructions on how to take the medicine.


Certain cephalosporins should not be combined with alcohol or with medicines that contain alcohol. Abdominal or stomach cramps, nausea, vomiting, facial flushing, and other symptoms may result within 15-30 minutes and may last for several hours. Alcoholic beverages or other medicines that contain alcohol should not be used while being treated with cephalosporins and for several days after treatment ends.

Special conditions

People with certain medical conditions or who are taking certain other medicines can have problems if they take cephalosporins. Before taking these drugs, the physician should be told about any of these conditions:
ALLERGIES. Severe allergic reactions to this medicine may occur. Anyone who is allergic to cephalosporins of any kind should not take other cephalosporins. Anyone who is allergic to penicillin should check with a physician before taking any cephalosporin. The physician should also be told about allergies to foods, dyes, preservatives, or other substances.
DIABETES. Some cephalosporins may cause false positive results on urine sugar tests for diabetes. People with diabetes should check with their physicians to see if they need to adjust their medication or their diets.
PHENYLKETONURIA. Oral suspensions of cefprozil contain phenylalanine. People with phenylketonuria (PKU) should consult a physician before taking this medicine.
PREGNANCY. Women who are pregnant or who may become pregnant should check with their physicians before using cephalosporins.
BREASTFEEDING. Cephalosporins may pass into breast milk and may affect nursing babies. Women who are breastfeeding and who need to take this medicine should check with their physicians. They may need to stop breastfeeding until treatment is finished.
OTHER MEDICAL CONDITIONS. Before using cephalosporins, people with any of these medical problems should make sure their physicians are aware of their conditions:
  • History of stomach or intestinal problems, especially colitis. Cephalosporins may cause colitis in some people.
  • Kidney problems. The dose of cephalosporin may need to be lowered.
  • Bleeding problems. Cephalosporins may increase the chance of bleeding in people with a history of bleeding problems.
  • Liver disease. The dose of cephalosporin may need to be lowered.
USE OF CERTAIN MEDICINES. Taking cephalosporins with certain other drugs may affect the way the drugs work or may increase the chance of side effects.

Side effects

Medical attention should be sought immediately if any of these symptoms develop while taking cephalosporins:
  • shortness of breath
  • pounding heartbeat
  • skin rash or hives
  • severe cramps or pain in the stomach or abdomen
  • fever
  • Severe watery or bloody diarrhea (may occur up to several weeks after stopping the drug)
  • unusual bleeding or bruising.
Other rare side effects may occur. Anyone who has unusual symptoms during or after treatment with cephalosporins should get in touch with his or her physician


Some cephalosporins cause diarrhea. Certain diarrhea medicines, such as diphenoxylate-atropine (Lomotil), may make the problem worse. A physician should be consulted before taking any medicine for diarrhea caused by taking cephalosporins.
Birth control pills may not work properly when taken at the same time as cephalosporins. To prevent pregnancy, other methods of birth control should be used in addition to the pills while taking cephalosporins.
Taking cephalosporins with certain other drugs may increase the risk of excess bleeding. Among the drugs that may have this effect when taken with cephalosporins are:
  • blood thinning drugs (anticoagulants) such as warfarin (Coumadin)
  • blood viscosity reducing medicines such as pentoxifylline (Trental)
  • the antiseizure medicines divalproex (Depakote) and valproic acid (Depakene)
Cephalosporins may also interact with other medicines. When this happens, the effects of one or both of the drugs may change or the risk of side effects may be greater. Anyone who takes cephalosporins should let the physician know all other medicines he or she is taking.

Key terms

Bronchitis — Inflammation of the air passages of the lungs.
Colitis — Inflammation of the colon (large bowel).
Gonorrhea — A sexually transmitted disease (STD) that causes infection in the genital organs and may cause disease in other parts of the body.
Inflammation — Pain, redness, swelling, and heat that usually develop in response to injury or illness.
Phenylketonuria (PKU) — A genetic disorder in which the body lacks an important enzyme. If untreated, the disorder can lead to brain damage and mental retardation.
Pneumonia — A disease in which the lungs become inflamed. Pneumonia may be caused by bacteria, viruses, or other organisms, or by physical or chemical irritants.
Sexually transmitted disease — A disease that is passed from one person to another through sexual intercourse or other intimate sexual contact. Also called STD.
Staph infection — Infection with Staphylococcus bacteria. These bacteria can infect any part of the body.
Strep throat — A sore throat caused by infection with Streptococcus bacteria. Symptoms include sore throat, chills, fever, and swollen lymph nodes in the neck.
Tonsillitis — Inflammation of a tonsil, a small mass of tissue in the throat.



"Newer Antibiotics Better for Throats" Pulse April 12, 2004: 18.
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
The genes for the production of ESBLs are carried on plasmids or transposons and may be transferred to other members of the family, hence making them resistant to cephalosporins. This is an extremely alarming situation as the dissemination of these resistant organisms will further limit the therapeutic options for treating typhoid.
Cephalosporin was the most prescribed group and given to 71.2% of the patients.
Trends in Neisseria gonorrhoeae susceptibility to cephalosporins in the United States, 20062014.
The increased frequency of ESBLs is closely linked with the injudicious use of different groups of antibiotics especially cephalosporins. These antibiotics are freely available over the counter and are used indiscriminately.
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Cephalosporins are most commonly and effectively used to treat outpatient indications of pneumonia, skin and soft tissue infections, sinusitis, urinary tract infections, and ear infections.
When penicillin skin test reagents are not available, the decision making between allergists and non-allergists in terms of beta-lactam prescription in patients with an unconfirmed history of an immediate reaction to penicillin was different in the case of first generation and third/fourth generation cephalosporins (P values < 0.01) but not with other drugs (Figure 3).
Following an assessment by the European Food Safety Agency, the British poultry industry voluntarily stopped using cephalosporins as of December 2011, the BPC added.
Unsuccessful treatment of gonorrhea with oral cephalosporins, such as cefixime, was identified in East Asia, beginning in the early 2000s, and in Europe within the past few years.
Current regulations allow Canadian farmers to give cephalosporins to animals without a prescription or a vet present, which allows for potential overuse and poses unknown risks to human and environmental health.
poultry producers have used cephalosporins very little since 2008, which is when the FDA first tried to restrict the drugs1 use in food animals.4 Today, cattle account for most veterinary prescriptions for antibiotics in this country, generally for treating pneumonia, foot rot, and mastitis, according to Gatz Riddell, a veterinarian and executive vice president of the American Association of Bovine Practitioners.