Home Drug Guide Colistimethate Sodium

Drug Guide

Generic Name

Colistimethate Sodium

Brand Names Coly-mycin M

Classification

Therapeutic: Antibiotic, Antimicrobial, Polymyxin

Pharmacological: Polymyxin E (colistin) derivative

FDA Approved Indications

Treatment of multidrug-resistant Gram-negative infections, including Pseudomonas aeruginosa, Acinetobacter baumannii, and Klebsiella pneumoniae.

Mechanism of Action

Disrupts bacterial cell membrane integrity by interacting with phospholipids, leading to leakage of cell contents and cell death.

Dosage and Administration

Adult: Dosage varies; typically 2.5–5 mg/kg/day divided into 2-4 doses, adjusted based on severity and site of infection.

Pediatric: Dosage based on weight; consult specific pediatric dosing guidelines.

Geriatric: Use with caution; dose adjustments may be necessary due to renal function.

Renal Impairment: Dose adjustment required based on renal function; monitor renal function closely.

Hepatic Impairment: No specific adjustments; monitor for toxicity.

Pharmacokinetics

Absorption: Poor oral absorption; administered parenterally.

Distribution: Widely distributed; penetrates lung and CSF poorly.

Metabolism: Not extensively metabolized; activated from colistimethate sodium.

Excretion: Renally excreted; adjust dose in renal impairment.

Half Life: Approximately 1.5–2 hours for colistimethate sodium; variable in renal impairment.

Contraindications

Known hypersensitivity to colistin or other polymyxins.

Precautions

Renal impairment, neuromuscular disorders, assessments of renal function essential before and during therapy.

Adverse Reactions - Common

Nephrotoxicity (Common)
Neurotoxicity (e.g., dizziness, weakness, parasthesias) (Less common)

Adverse Reactions - Serious

Respiratory failure (Rare)
Allergic reactions including rash, anaphylaxis (Rare)

Drug-Drug Interactions

Aminoglycosides, vancomycin, other neurotoxic or nephrotoxic agents—may increase risk of toxicity.

Drug-Food Interactions

N/A

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor renal function (BUN, creatinine), neuro status, and signs of toxicity.

Diagnoses:

Risk for nephrotoxicity
Risk for neurotoxicity

Implementation: Administer as per prescribed dose; ensure proper reconstitution and infusion techniques.

Evaluation: Regularly assess renal function, neurological status, and signs of adverse reactions.

Patient/Family Teaching

Report any signs of nephrotoxicity (decreased urine output, swelling).
Inform about potential neurotoxic symptoms (dizziness, weakness).
Maintain hydration to promote renal function.

Special Considerations

Black Box Warnings:

Nephrotoxicity and neurotoxicity risk; use with caution.

Genetic Factors: No specific genetic markers identified affecting dosing or toxicity.

Lab Test Interference: None known.

Overdose Management

Signs/Symptoms: Signs of neurotoxicity or nephrotoxicity—e.g., ringing in ears, weakness, or kidney dysfunction.

Treatment: Discontinue drug, provide supportive care, consider hemodialysis in severe cases.

Storage and Handling

Storage: Store at room temperature, protected from light.

Stability: Stable at room temperature for specified period as per manufacturer.