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First generation cephalosporins

Written on June 29, 2018 by C. Fookes, BPharm

Medically reviewed on June 29, 2018

What are First generation cephalosporins?

Cephalosporins are a large group of antibiotics derived from the mold Acremonium (previously called Cephalosporium). Cephalosporins are bactericidal (kill bacteria) and work in a similar way to penicillins. They bind to and block the activity of enzymes responsible for making peptidoglycan, an important component of the bacterial cell wall. They are called broad-spectrum antibiotics because they are effective against a wide range of bacteria.

Since the first cephalosporin was discovered in 1945, scientists have been improving the structure of cephalosporins to make them more effective against a wider range of bacteria. Each time the structure changes, a new "generation" of cephalosporins are made. So far there are five generations of cephalosporins. All cephalosporins start with cef, ceph, or kef. Note that this classification system is not used consistently from country to country.

First generation cephalosporins refer to the first group of cephalosporins discovered. Their optimum activity is against gram-positive bacteria such as staphylococci and streptococci. They have little activity against gram-negative bacteria.

What are first generation cephalosporins used for?

First generation cephalosporins may be used to treat infections caused by susceptible bacteria such as:

  • Bone infections
  • Ear infections (eg, otitis media)
  • Skin infections
  • Upper respiratory tract infections
  • Urinary tract infections.

What are the differences between first generation cephalosporins?

Cephalexin and cefadroxil can be given by mouth, whereas cefazolin can only be given by injection (IV/IM). There are also differences with regards to how frequently the different first-generation cephalosporins need to be dosed.

Generic name Brand name examples
cefadroxil Duricef
cefazolin Ancef, Kefzol
cephadrine Discontinued
cephalexin Daxbia, Keflex

Are first generation cephalosporins safe?

First generation cephalosporins are generally safe, with low toxicity and good efficacy against susceptible bacteria.

Allergic reactions have been reported with cephalosporins (including first generation cephalosporins) and symptoms may include a rash, hives (urticaria), swelling, or rarely, anaphylaxis. Up to 10% of people with a history of penicillin allergy will also be allergic to cephalosporins.

Rarely, seizures have been reported with some cephalosporins; the risk is greatest in those with kidney disease.

Cephalosporins have also been associated with a reduced ability of the blood to clot leading to prolonged bleeding times. People with kidney or liver disease, nutritionally deprived, taking cephalosporins long-term, or concurrently receiving anticoagulant therapy are more at risk.

For a complete list of severe side effects, please refer to the individual drug monographs.

What are the side effects of first generation cephalosporins?

First generation cephalosporins generally cause few side effects. The most common side effects reported include diarrhea, nausea and vomiting, dyspepsia, gastritis and abdominal pain. Transient liver problems have also been reported.

Rarely, some people may develop a super-infection due to overgrowth of a naturally occurring bacterium called Clostridium difficile, following use of any antibiotic, including cephalosporins. Symptoms may include severe diarrhea.

Uncommonly, an overgrowth of the yeast, Candida albicans, may occur following cephalosporin use, resulting in the symptoms of thrush.

For a complete list of side effects, please refer to the individual drug monographs.

List of First generation cephalosporins:

Filter by:
Drug NameView by: Brand | Generic Reviews Avg. Ratings
Duricef (Pro)
generic name: cefadroxil
0 reviews
   
10
Velosef
generic name: cephradine
0 reviews
   
10
Kefzol
generic name: cefazolin
0 reviews
   
9.0
Keflex (Pro)
generic name: cephalexin
56 reviews
   
7.9
Ancef (Pro)
generic name: cefazolin
0 reviews
   
6.5
Biocef
generic name: cephalexin
0 reviewsAdd rating
Panixine
generic name: cephalexin
0 reviewsAdd rating

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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