Imipenem/Cilastatin (Primaxin)
Antibiotic | Anti-Infective Agent
- Broad-Spectrum Antibacterial Activity:
- Primaxin is a combination antibiotic containing imipenem and cilastatin. Imipenem is a broad-spectrum beta-lactam antibiotic, and cilastatin is a renal dehydropeptidase inhibitor that prevents the degradation of imipenem in the kidneys, enhancing its efficacy. It is effective against a wide range of Gram-positive and Gram-negative bacteria, including some anaerobic species.
- Indications and Usage:
- Primarily used for the treatment of serious infections such as lower respiratory tract infections, urinary tract infections, intra-abdominal infections, gynecological infections, bacterial septicemia, and skin/skin structure infections. It is especially useful in cases of polymicrobial infections and infections due to multi-drug resistant bacteria.
- Dosing Considerations:
- The dosage of Primaxin may vary based on the severity and type of infection. It is crucial to adjust the dose in patients with renal impairment to avoid toxicity. Regular monitoring of renal function is recommended.
- Administration Guidelines:
- Primaxin should be administered intravenously. Ensure correct IV infusion techniques to avoid phlebitis or thrombophlebitis. Do not administer intramuscularly or subcutaneously.
- Drug Interactions:
- Be aware of potential drug interactions. For example, Primaxin may decrease serum levels of valproic acid, potentially reducing its effectiveness in controlling seizures. It may also interact with other nephrotoxic drugs, enhancing the risk of renal damage.
- Side Effects and Monitoring:
- Common side effects include gastrointestinal disturbances (nausea, vomiting, diarrhea), skin rash, and possible CNS effects such as seizures. Severe hypersensitivity reactions may occur in patients with a history of penicillin allergy due to possible cross-reactivity.
- Contraindications and Precautions:
- Contraindicated in patients with a known hypersensitivity to any component of Primaxin or other beta-lactam antibiotics. Use cautiously in patients with CNS disorders like epilepsy, as imipenem may lower the seizure threshold.
- Special Patient Populations:
- In elderly patients, dose adjustments may be necessary based on renal function. Use in pregnancy only if clearly needed, under close supervision, as there are no adequate and well-controlled studies in pregnant women. It is generally considered safe in lactation under medical advice.
- Antibiotic Stewardship:
- Emphasize the importance of using Primaxin judiciously to prevent the development of antibiotic resistance. It should be reserved for confirmed or strongly suspected bacterial infections where less potent antibiotics are inappropriate.
- Therapeutic Monitoring:
- Monitor therapeutic effectiveness by observing the reduction in specific infection markers and symptoms. Also, monitor for any adverse reactions or signs of superinfection during therapy.
https://www.merck.com/product/usa/pi_circulars/p/primaxin/primaxin_iv_pi.pdf —
prescribing information
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