There are many antibiotics veterinarians can choose from, but imipenem for dogs with infections is one of those second-line of drugs to select only when the first-line antibiotics have proven to be ineffective. Imipenem is therefore effective for those stubborn infections that are reluctant to heal. While this drug is very potent and can kill many infectious agents, as one may imagine, use of such a drug can have a multitude of side effects which is why imipenem should used with the utmost caution and should only be given under the guidance of a veterinarian.
About This Drug
Imipenem, also known as Primaxin, is a medication that belongs to a class of antibiotics known as carbapenems, basically, antibiotics that are mean to treat infections that are suspected to be caused by multidrug-resistant (MDR) bacteria.
Veterinarians may therefore prescribe this drug to dogs suffering from stubborn infections such as urinary tract infections, infections of the digestive tract caused by E-coli, skin infections, bone infections, infections of the inner lining of the heart, lower upper respiratory tract infections and pneumonia.
Imipenem is a broad-spectrum antibiotic that is capable of fighting against gram-positive and gram-negative organisms, anaerobic bacteria and bacteria that produce beta-lactamases. While imipenem is not approved by the FDA for use in animals, veterinarians can prescribe it legally as an extra-label drug.
Imipenem is given to dogs by an intramuscular shot or can be administered by IV at regular dosages. This means, that your dog must see the vet to have dosages of this drug administered. In most cases, this drug is administered to hospitalized pets.
How this Drug Works
Multiple drug resistance (MDR) refers to resistance to certain antibiotics shown by certain types of microorganisms. This is obviously a concern, considering that many antibiotics are ineffective when dealing with such organisms. Imipenem is effective because it works on preventing the invading organisms from penetrating cell walls which leads to them breaking up and dying.
While effective, Imipenem though is inactivated by an enzyme produced by the kidneys known as renal dehydropeptidase. Because of this, this drug is often used in combination with cilastatin, a special enzyme that works as a DHP-I inhibitor, increasing the half life of imipenem and its excretion from the dog's kidneys through the urine. The addition of this enzyme is therefore meant to potentiate the effectiveness of this drug and reduce toxicity.
Side Effects of Imipenem
While imipenem is a very potent antibiotic, it can cause a variety of side effects. Digestive issues can be common, often causing nausea, drooling, vomiting and diarrhea. At a skin level, this drug can cause rashes and irritations and pain at the injection site. On a more serious, systemic level, imipenem may cause seizures, bone marrow depression, hepatitis, kidney failure and heart problems.
Imipenem should be used with caution in dogs suffering from pre-extisting kidney failure If this drug must be used in these subjects, it's important to carefully monitor kidney function through chemical profile blood tests.
To provide the best benefit to the dog and decrease the risk of drug-resistant bacteria, Imipenem should only be given in presence of a proven,or otherwise, strongly suspected bacterial infection.
- Antibiotics and Acute Renal Failure: Caitriona M. Matthews, DVM; Melinda S. Camus, DVM; Bruce E. LeRoy, DVM, DACVP, PhD. Veterinary Clinical Pathology Clerkship Program