Imipenem/cilastatin

A combination antibiotic used to treat bacterial infections

Imipenem/cilastatin

Chemical structure of imipenem and cilastatin

Imipenem/cilastatin is a combination antibiotic used in the treatment of a variety of bacterial infections. It consists of two active components: imipenem, a broad-spectrum beta-lactam antibiotic, and cilastatin, a renal dehydropeptidase inhibitor.

Pharmacology

Imipenem is a member of the carbapenem class of antibiotics, which are known for their broad-spectrum activity against both Gram-positive and Gram-negative organisms. It works by inhibiting bacterial cell wall synthesis, leading to cell lysis and death.

Cilastatin is not an antibiotic itself but is included in the formulation to inhibit the enzyme dehydropeptidase I in the kidneys. This enzyme would otherwise degrade imipenem, reducing its efficacy. By inhibiting this enzyme, cilastatin increases the concentration of imipenem in the body, enhancing its antibacterial activity.

Clinical Uses

Imipenem/cilastatin is used to treat a wide range of infections, including:

• Complicated urinary tract infections
• Intra-abdominal infections
• Skin and soft tissue infections
• Bacterial septicemia
• Lower respiratory tract infections

It is often reserved for severe infections or those caused by multi-drug resistant organisms due to its broad spectrum and potency.

Administration

The combination is typically administered intravenously, as imipenem is not absorbed orally. The dosage and duration of treatment depend on the type and severity of the infection, as well as the patient's renal function.

Side Effects

Common side effects of imipenem/cilastatin include:

• Nausea
• Vomiting
• Diarrhea
• Rash

Serious side effects can include seizures, particularly in patients with pre-existing central nervous system disorders or renal impairment.

Mechanism of Resistance

Resistance to imipenem can occur through several mechanisms, including the production of carbapenemase enzymes by bacteria, which hydrolyze the antibiotic, rendering it ineffective. Other mechanisms include alterations in bacterial porin channels and efflux pump overexpression.

Related pages

• Antibiotic resistance
• Beta-lactam antibiotics
• Carbapenem-resistant Enterobacteriaceae