What is polymyxin B used for and how does it work?

Polymyxin B can be [used to treat a variety of infections](https://accpjournals.onlinelibrary.wiley.com/doi/full/10.1002/phar.2209), such as those in the urinary tract, brain, and blood, caused by certain bacteria. It kills bacteria by destroying the protective covering around them.

When is polymyxin B typically used?

Polymyxin B is an older antibiotic that isn't commonly used today because it's linked to [serious side effects](https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=b56f18c0-ef5e-4ed9-a5af-f79f3cd189b6&type=display#BOX), like kidney damage. It's usually only used in the hospital to treat serious infections [when safer antibiotics don't work well](https://pharmrev.aspetjournals.org/content/73/2/679) because of [antibiotic resistance](https://www.goodrx.com/health-topic/infections/superbugs-and-antibiotic-resistance). Depending on the type and severity of the infection, your provider might give polymyxin B to you by itself or together with another antibiotic.

How is polymyxin B given and how much will I receive?

Polymyxin B is typically given as an injection through the veins (IV). But it can also be injected directly into the fluid around the spinal cord for certain types of [meningitis](https://www.goodrx.com/conditions/meningitis/meningitis-causes-symptoms-treatment-prevention). The [dose of polymyxin B can differ](https://accpjournals.onlinelibrary.wiley.com/doi/full/10.1002/phar.2209) from person to person depending on your age, weight, the type of infection, and if you have kidney problems.

What side effects can polymyxin B cause?

Some side effects you might experience from polymyxin B include rash, pain at the injection site, and fever. In addition, Polymyxin B has a [black box warning](https://www.goodrx.com/drugs/safety/fda-black-box-warning) (warning for extremely serious side effects) for [kidney damage and nervous system problems](https://dailymed.nlm.nih.gov/dailymed/fda/fdaDrugXsl.cfm?setid=b56f18c0-ef5e-4ed9-a5af-f79f3cd189b6&type=display#BOX). Don't use this medication with other medications that can also damage your kidneys or cause nervous system problems. Let your provider know if you experience symptoms include feeling irritable, weakness, drowsiness, numbness in the hands and feet, and not making much urine.

polymyxin B

Generic Aerosporin

Used for Bacterial Infection, Eye Infection, Meningitis, Urinary Tract Infection

Polymyxin B can be used to treat infections in the urinary tract, brain, and blood. It's infused through the veins (IV) by a healthcare provider. Polymyxin B is an older antibiotic that's not commonly used today because of the risk of serious side effects, such as kidney problems. But it's still considered a good choice for some resistant bacteria that don't respond well to safer, first-choice antibiotics.

Reviewed by:

Robert Chad Hakim, PharmD, BCCCP

Kristianne Hannemann, PharmD

Last reviewed on May 24, 2022

What is Polymyxin B?

Are you looking for information on bacitracin / polymyxin B (Ak-Poly-Bac) eye ointment or bacitracin / neomycin / polymyxin B (Neosporin) topical ointment instead?

Drug facts

Common BrandsAerosporin(brand no longer available)

Drug ClassAntibiotic

Controlled Substance ClassificationNot a controlled medication

Generic StatusNo lower-cost generic available

AvailabilityPrescription only

Common questions about Polymyxin B

Polymyxin B can be used to treat a variety of infections, such as those in the urinary tract, brain, and blood, caused by certain bacteria. It kills bacteria by destroying the protective covering around them.

Polymyxin B is an older antibiotic that isn't commonly used today because it's linked to serious side effects, like kidney damage. It's usually only used in the hospital to treat serious infections when safer antibiotics don't work well because of antibiotic resistance. Depending on the type and severity of the infection, your provider might give Polymyxin B to you by itself or together with another antibiotic.

Polymyxin B is typically given as an injection through the veins (IV). But it can also be injected directly into the fluid around the spinal cord for certain types of meningitis. The dose of Polymyxin B can differ from person to person depending on your age, weight, the type of infection, and if you have kidney problems.

Some side effects you might experience from Polymyxin B include rash, pain at the injection site, and fever. In addition, Polymyxin B has a black box warning (warning for extremely serious side effects) for kidney damage and nervous system problems. Don't use this medication with other medications that can also damage your kidneys or cause nervous system problems. Let your provider know if you experience symptoms include feeling irritable, weakness, drowsiness, numbness in the hands and feet, and not making much urine.

How to save using GoodRx

1. Compare PricesSpecify your dosage and quantity to find out exactly how much you can save.

2. Select your free couponYou can use the displayed coupon, or compare prices at other pharmacies near you.

3. Show coupon to your pharmacistPresent your printed or electronic coupon when you pick up your prescription.

Get free coupon Learn more

Polymyxin B dosage

Typical dosage for Polymyxin B

Interactions between Polymyxin B and other drugs

Polymyxin B may interact with certain medications or supplements. Always let your doctor and pharmacist know about any other medications or supplements (including prescribed and over-the-counter medications, vitamins, and dietary or herbal supplements) that you are currently taking. The list below does not include all possible drug interactions with Polymyxin B. Please note that only the generic name of each medication is listed below.

Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are receiving this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.

Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.