Cefotaxime: Chemical Formula, Presentation, Indications, Action Mechanism, Dosage, Side Effects, Warnings and Interactions

It is a semisynthetic third-generation cephalosporin antibiotic with bactericidal activity.

Cefotaxime inhibits the synthesis of mucopeptides by binding and inactivating proteins, interfering with the final transpeptidation step required for the cross-linking of peptidoglycan units that are a component of bacterial cell walls.

This results in a reduction in the stability of the cell wall and causes cell lysis.

Chemical formula

  • C16H17N5O7S2.


This medicine is available in an injectable form to be administered directly intravenously or intramuscularly.


Cefotaxime is a prescription medication used to treat bacterial infections, including lung, skin, joints, bones, urinary tract, and gynecological disorders.

Mechanism of action

Cefotaxime, like other beta-lactam antibiotics, is mainly bactericidal.

It inhibits bacterial cell wall synthesis when it binds preferentially with specific penicillin-binding proteins located within the bacterial cell wall.


Resistance to beta-lactam antibiotics can develop if there are changes in specific penicillin-binding proteins, if the permeability of the cell wall decreases, or if certain beta-lactamases are present.

Cefotaxime retains activity against some beta-lactamase-producing isolates, including penicillinase and cephalosporins; however, most extended-spectrum beta-lactamase cultures and carbapenemase producers are resistant to the drug.


The recommended dose of cefotaxime will be based on certain conditions such as:

  • The state that is being treated with the medicine.
  • Other medical conditions that the patient has.
  • Other medications the patient is taking.
  • The patient’s response to the drug.
  • The renal function of the patient.
  • The weight and age of the patient.

The recommended dose range for cefotaxime in adults is 0.5 grams once a day at 12 grams divided into multiple doses per day.

The recommended dose range for cefotaxime in children includes the following.

  • From 0 to 1 week of age: 50 mg/kg of body weight in doses every 12 hours, intravenously.
  • From 1 to 4 weeks of age: 50 mg/kg of body weight in doses every 8 hours intravenously.
  • If you have one month to 12 years: less than 50 kg, a dose of 50 to 180 mg per kg of body weight intravenously intramuscularly divided into four to six equal amounts. Greater than or equal to 50 kilograms use the usual dose for adults, with a maximum of 12 grams.

Maximum dosage

  • Adult patients, geriatric, adolescents, and children over 50 kg:  12 g / day.
  • In children less than 50 kg: 180 mg / kg / day.
  • In neonates older than 7 days: 150 mg / kg / day, 7 days or less: 100 mg / kg / day.

Side effects

Call your doctor right away if you have a severe side effect, such as:

  • Watery or bloody diarrhea.
  • Skin rash, bruising, severe tingling, numbness, pain, muscle weakness.
  • Uneven heartbeats.
  • Fever, chills, body aches, flu symptoms.
  • Bruising or easy bleeding, unusual weakness.
  • Fever, sore throat, and headache with a rash with blisters, peeling, and red coloring.
  • Convulsions
  • Jaundice (yellow color of the eyes or skin).

Less serious side effects may include:

  • Pain, irritation, or a hard lump where the injection was given.
  • Stomach pain, nausea, vomiting.
  • Headache.
  • Itching or vaginal discharge.

Warnings and contraindications

Do not take cefotaxime if:

  • The patient is allergic to cefotaxime or any of its ingredients.
  • The patient is allergic to similar antibiotics such as penicillins and cephalosporins.

Before taking cefotaxime, you should inform the doctor about medical conditions. Especially in the cases of:

  • Presenting any other type of allergy.
  • Causes gastrointestinal problems, especially colitis.
  • Present kidney problems.
  • Present diabetes.
  • Presenting heart rhythm disorders.
  • Be pregnant.

Cefotaxime has been detected in human breast milk.

Due to the possibility of adverse reactions in infants from cefotaxime, the decision should be made to stop breastfeeding or discontinue the use of cefotaxime.

The importance of the medication for the mother must be considered.


The doctor should be informed about the medications you are taking, including over-the-counter medicines, vitamins, and herbal supplements.

You should primarily inform the doctor if you take probenecid,  methotrexate, birth control pills, warfarin, or aminoglycosides such as amikacin or gentamicin tobramycin.