Cefotixin (Mefoxin®)

Overview

Cefotixin sodium is an antibiotic. It is further categorized as a second-generation cephalosporin produced by Streptomyces lactamdurans. 

It is a parenterally administered antibiotic that is active against a wide range of gram-positive and gram-negative bacteria, including anaerobic species.

Cephalosporins, in general have greater activity against gram-negative bacteria than penicillins. Gram-positive organisms that are susceptible to cefoxitin include:Staphylococcus aureus, Staphylococcus epidermidis, beta-hemolytic and other streptococci (Streptococcus fecalis is resistant), Mycobacteria species, and Streptococcus pneumoniae. Susceptible gram-negative organisms include: Eikenella corrodens (beta-lactamase negative strains), Escherichia coli, Klebsiella species, Haemophilus influenzae, Proteus mirabilis, Morganella morganii, Proteus vulgaris, and Providencia species. Susceptible anerobic organisms include: Peptococcus niger, Peptostreptococcus species, Clostridium species, and Bacteroides species. 

Cefoxitin is resistant to both penicillinase and cephalosporinase.

Its antibiotic action is achieved through inhibition of mucopeptide synthesis in the bacterial cell wall. 

Following intravenous administration, peak blood levels of cefoxitin are achieved rapidly (~5 minutes) and it is widely distributed in tissues. Its half-life in humans is 41 to 59 minutes (half-life in veterinary species is similar) and it is eliminated largely unchanged by the kidneys.

Cefotixin is a prescription drug and can only be obtained from a veterinarian or by prescription from a veterinarian.

This drug is not approved for use in animals by the Food and Drug Administration but it is prescribed legally by veterinarians as an extra-label drug.

Cefoxitin is not effective against infections caused by parasites (intestinal worms), mites, viruses, or fungi.

Brand Names and Other Names

This drug is registered for use in humans only.

Human formulations: Mefoxin® (Merck)

Veterinary formulations: None

Uses of Cefoxitin

Cefoxitin is used in both dogs and cats to treat a variety of bacterial infections, including:

Respiratory tract infections

Urogenital tract infections

Intra-abdominal infections

Septicemia

Bone and joint infections

Skin infections

Perioperative prophylaxis

Precautions and Side Effects

While generally safe and effective when prescribed by a veterinarian, cefoxitin can cause side effects in some animals.

Cefoxitin should not be used in animals with known hypersensitivity or allergy to it or other cephalosporins. In addition, it should be used cautiously in patients sensitive to other beta-lactam antibiotics. 

Pain may occur on intramuscular (IM) injection of cefoxitin. 

During treatment with cefoxitin, gastrointestinal flora may become disturbed, causing diarrhea. 

High doses of cefoxitin can cause nephrotoxicity, neurotoxicity, hepatitis, changes in the blood leucogram and thrombocytopenia. 

The dose of cefoxitin is often reduced in patients with compromised renal function.

Drug Interactions

Cefoxitin may interact with other medications. Consult with your veterinarian to determine if other drugs your pet is receiving could interact with cefoxitin. Such drugs include certain other antibiotics.

When mixed with aminoglycosides, incompatibility may occur. These drugs can be administered separately, if they are to be used in the same patient. 

How Cefoxitin is Supplied

Powder for injection: 1 g and 2 g vials and infusion bottles or 10 g bulk bottles.

Injection: 1 g or 2 g with dextrose premixed in 50 mL plastic containers.

Dosing Information

Medication should never be administered without first consulting your veterinarian. 

The usual dose is 5 to 15 mg per pound (10 to 30 mg/kg) every 6 to 8 hours subcutaneously, intramuscularly or intravenously for dogs and cats. 

After receiving cefoxitin, many pets are sent home with a prescription of an oral cephalosporin, similar to cefoxitin.

The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects. Be certain to complete the prescription unless specifically directed by your veterinarian. Even if your pet feels better, the entire treatment plan should be completed to prevent relapse or prevent the development of resistance.