What Is Colistin Used For and How Does it Work?

Colistin is used to treat certain bacterial infections.

Colistin is available under the following different brand names: colistimethate sodium and Coly Mycin M.

What Are Dosages of Colistin?

Dosages of Colistin:

Dosage Forms and Strengths

Powder for Injection

  • 150 mg/vial

Dosage Considerations – Should be Given as Follows:

Susceptible Infections

  • Dosage expressed in terms of colistin base
  • 2.5-5 mg/kg/day divided every 6-12 hours intravenously/intramuscularly (IV/IM); not to exceed 5 mg/kg/day
  • Children under 12 years old: Safety and efficacy not established

Renal Impairment

  • CrCl greater than 80 mL/minute: No dosage adjustment required
  • CrCl 50-79 mL/minute: 2.5-3.8 mg/kg/day IV/IM divided every 12 hours
  • CrCl 30-49 mL/minute: 2.5 mg/kg/day IV/IM once daily or divided every 12 hours
  • CrCl 10-29 mL/minute: 1.5 mg/kg IV/IM every 36 hours

Other Indications and Uses

  • Gram-neg. infection (e.g., Enterobacter aerogenes, E. coli, Klebsiella, Pseudomonas) unresponsive to other antibiotics
  • Multi-drug resistant gram-negative infection

What Are Side Effects Associated with Using Colistin?

Common side effects of colistin include:

  • Dizziness
  • Numbness, tingling, prickling, burning sensation especially of extremities and tongue

Less common side effects of colistin include:

  • Neurotoxicity
  • Kidney toxicity
  • Acute respiratory failure (inhalation route)
  • Respiratory tract paralysis

Other side effects of colistin include:

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

What Other Drugs Interact with Colistin?

If your doctor has directed you to use this medication, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider, or pharmacist first.

What Are Warnings and Precautions for Colistin?


This medication contains colistin. Do not take colistimethate sodium and Coly Mycin M if you are allergic to colistin or any ingredients contained in this drug.


  • Hypersensitivity

Effects of Drug Abuse

  • No information available

Short-Term Effects

  • See "What Are Side Effects Associated with Using Colistin?"

Long-Term Effects

  • See "What Are Side Effects Associated with Using Colistin?"


  • Do not exceed 5 mg/kg/day (as colistin base) with normal renal function
  • Not indicated for infections by Proteus or Neisseria (most strains are resistant)
  • Risk of nephrotoxicity, neurotoxicity; discontinue if elevated BUN/creatinine
  • Risk of respiratory arrest in myasthenia gravis or concomitant anesthetics or neuromuscular blocking drugs
  • Risk of C. difficile-associated pseudomembranous colitis
  • Sedative effects may impair driving, operating machinery

Pregnancy and Lactation

Use colistin with caution during pregnancy if benefits outweigh risks. Animal studies show risk and human studies are not available or neither animal nor human studies were done.

It is unknown if colistin passes into breast milk or how it would affect a nursing infant. Use caution while breastfeeding.


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