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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.


a group of broad-spectrum, semisynthetic antibiotics, derived from Cephalosporium, a genus of soil-inhabiting fungi, which share the nucleus 7-aminocephalosporanic acid. Cephalosporins named before 1975 are spelled with 'ph', while those named later are spelled with 'f'.
First generation preparations (cefaclor, cephazolin, cefadroxil, cephalexin, cephaloglycin, cephaloridine, cephalothin, cephapirin, cephradine) are active mainly against gram-positive bacteria. Second generation preparations (cephamandole and cefoxitin) have a broader spectrum of activity and third generation preparations (cefoperazone, cefotaxime and moxalactam) are active mainly against gram-negative organisms, including Pseudomonas aeruginosa.
In a more recently introduced system of classification, cephalosporins are grouped according to their route of administration and antimicrobial activity. The orally active cephalosporins, with fair activity against gram-positive bacteria and modest activity against gram-negative, but not Pseudomonas, form one group. Included are cephalexin, cephadrine, cefadroxil, cefachlor and cephaloglycin.
Those active by parenteral administration are placed into four groups: Group I, which includes cefapirin, cefacetrile, cephaloridine, cephalothin and cephazolin, has high activity against gram-positive bacteria and moderate activity against gram-negative, but not Pseudomonas; Group II, which includes cefamandole, cefmenoxime, cefotaxime, cefotiam, ceftiofur, cefuroxime and cefotriaxone, has high activity against Enterobacteriaceae; Group III, which includes cefulodin, ceftazidime and cefoperazone, has high activity against Pseudomonas and other gram-negative bacteria; Group IV, which includes cefoxitin, loxalactam, cefmetazole and cefotetan, is resistant to β-lactamase.
References in periodicals archive ?
The sensitive and resistance rates to 2nd and 3rd generation cephalosporins and monocyclic lactams were close, but resistance rate to cefoxitin was very low.
Dual therapy with gentamicin (240 mg single intramuscular dose) and azithromycin (2 grams single oral dose) is the treatment of choice for pregnant patients with severe penicillin or cephalosporin allergy.
The biocatalytic conversion for CPC into 7-ACA, the key intermediate to cephalosporin derivates was developed (5).
In Pakistan the first third generation cephalosporin resistant Shigella flexneri was isolated in The Aga Khan University Hospital, Karachi, Pakistan, in 2005, but it was not ESBL producer8.
Resistance to 3rd generation cephalosporins has also been reported from other countries.
Continued surveillance of gonococcal antimicrobial susceptibilities is vital to inform treatment guidelines and mitigate the spread of isolates with decreased susceptibility to cephalosporins and resistance to azithromycin.
The increased frequency of ESBLs is closely linked with the injudicious use of different groups of antibiotics especially cephalosporins.
Technavio's report, Global Cephalosporin Drugs Market 2015-2019, has been prepared based on an in-depth market analysis with inputs from industry experts.
Finally, to evaluate the impact of the infections caused by enterobacteria resistant to third-generation cephalosporins on hospital length of stay, a Cox proportional hazards analysis was conducted.
The most commonly used classification system categorizes cephalosporins using the term "generations.
Cephalosporins were only used in breeding flocks so it seems a bit odd to extrapolate Dutch figures to the British industry as we never used cephalosporins in broiler flocks," the British Poultry Council (BPC) said.