Bacitracin

Skin Infections

The topical form of bacitracin is used to prevent minor skin infections in people with small cuts, scrapes, or burns. It works by stopping the growth of bacteria in the affected area.

Eye Infections

Bacitracin ophthalmic ointment is used to treat infections of the eye or eyelid caused by specific types of bacteria.

Internal Infections

In some cases, bacitracin is given by injection. This form is primarily used to treat infants with pneumonia or a buildup of pus in the chest (empyema) caused by staphylococci bacteria that are sensitive to the medication.

Limitations

Bacitracin only treats bacterial infections. It will not work for infections caused by viruses, such as the common cold or flu, or for fungal infections. Using an antibiotic when it is not needed increases the risk of getting an infection later that resists antibiotic treatment.

Mechanism of Action

Bacitracin belongs to a class of medications known as antibiotics. It works by interfering with the way bacteria build their cell walls. The cell wall is a critical outer layer that bacteria need to survive, maintain their shape, and protect themselves from their environment.

By preventing the formation of this wall, bacitracin stops the bacteria from reproducing and growing. This process helps the body's immune system clear the infection more effectively. Depending on the concentration used and the type of bacteria present, bacitracin can either stop the growth of bacteria or kill them directly.

Scope of Activity

It is important to understand how bacitracin interacts with different types of germs:

• Targeted Bacteria: Bacitracin is primarily effective against gram-positive bacteria, such as staphylococci and streptococci, which are common causes of skin and eye infections.
• Bacterial Infections Only: This medication only works against bacterial infections. It is not effective against infections caused by viruses (such as the common cold or herpes) or fungi (such as athlete's foot).
• Local Treatment: When applied as an ointment or solution to the skin or eyes, the medication acts locally. This means it works directly at the site of a minor cut, scrape, or burn to prevent or treat an infection without being absorbed significantly into the rest of the body.

Common Side Effects

The most common side effects of bacitracin are typically mild and occur at the site where the medication is applied. These may include:

• Mild skin irritation, itching, or redness
• Burning or stinging sensations
• Temporary blurred vision (when using ophthalmic ointment)
• Increased tearing of the eyes

Serious Side Effects

Although rare, some individuals may experience a severe allergic reaction. Seek immediate medical attention if you notice any of the following symptoms:

• Hives or a widespread skin rash
• Swelling of the face, lips, tongue, or throat
• Difficulty breathing or swallowing
• Severe dizziness

If you develop new or worsening skin irritation, redness, or swelling that was not present before you started using the medication, stop use and contact a healthcare professional.

Kidney Toxicity (Boxed Warning)

When administered by injection, bacitracin can cause serious kidney damage, known as nephrotoxicity. This may lead to kidney failure. Because of this risk, kidney function is typically monitored through laboratory tests before and during treatment. Healthcare providers also monitor fluid intake and urinary output closely to watch for signs of toxicity.

Drug Interactions

The risk of kidney damage is higher if bacitracin injection is used at the same time as other medications that can harm the kidneys. These include certain other antibiotics such as streptomycin, kanamycin, polymyxin B, colistin, and neomycin.

Allergic Reactions

Allergic reactions can occur with both the topical and injectable forms of bacitracin. Symptoms may include a skin rash, itching, or hives. While rare, severe and life-threatening allergic reactions, such as anaphylaxis, have been reported. If a rash or other signs of an allergic reaction appear, the medication should be discontinued immediately.

Topical Use Precautions

Topical bacitracin is for external use only and must not be used in the eyes. It should not be applied over large areas of the body or used on deep puncture wounds, animal bites, or serious burns unless directed by a healthcare professional. If a skin condition persists or worsens after several days of treatment, medical advice should be sought.

Risk of Superinfection

Using bacitracin for a long period may result in the overgrowth of organisms that are not sensitive to the antibiotic, including fungi. If a new infection develops during treatment, a healthcare provider should evaluate the condition.

Pregnancy

There is limited information regarding the safety of bacitracin during pregnancy. Animal reproduction studies have not been conducted with this medication, and it is unknown whether bacitracin can cause harm to a fetus or affect reproductive capacity. Healthcare providers typically recommend using bacitracin during pregnancy only if it is clearly needed.

Breastfeeding

It is not known if bacitracin passes into breast milk or if it could harm a nursing infant. If you are breastfeeding or planning to breastfeed, consult your doctor or pharmacist to determine if the benefits of using this medication outweigh the potential risks to the baby.

Topical Ointment

Bacitracin is commonly available as an ointment for application to the skin. It is often used for minor cuts, scrapes, or burns and is available both over-the-counter and by prescription.

Ophthalmic Ointment

A sterile ointment form is available specifically for treating bacterial infections of the eye. This form is formulated to be safe for use on the surface of the eye.

Powder for Injection

Bacitracin is produced as a sterile powder in vials for intramuscular injection. This form is typically prepared by dissolving the powder in a liquid and is administered by healthcare professionals in a clinical setting.

FDA Approval and Indications

Bacitracin is a polypeptide antibiotic that has been FDA-approved for several decades. Its regulatory status and approved uses depend on the specific formulation:

• Topical use: Approved for the prevention of localized skin infections in minor cuts, scrapes, and burns. These products are widely available over-the-counter.
• Ophthalmic use: Approved for the treatment of superficial infections of the eye, such as those affecting the conjunctiva or cornea. These formulations require a prescription.
• Injectable use: Approved for intramuscular administration specifically for infants with staphylococcal pneumonia and empyema when the infection is caused by susceptible organisms.

Boxed Warning

The FDA has issued a boxed warning for the injectable (intramuscular) form of bacitracin. This warning highlights the risk of nephrotoxicity, or kidney damage, which can occur even when the drug is used at recommended doses. Due to this risk, the injectable form is restricted to specific clinical situations where other treatments are not appropriate, and it requires frequent monitoring of kidney function.

Application Instructions

Bacitracin ointment is applied topically to the skin to help prevent infection in minor injuries. Before application, the affected area should be cleaned and dried. A small amount of ointment, typically an amount equal to the surface of a fingertip, is applied to the wound one to three times per day.

The treated area may be covered with a sterile bandage if necessary. It is important to wash your hands before and after use to prevent the spread of bacteria.

Usage Considerations

This medication is for external use only and should not be used in the eyes or over large areas of the body. Users should stop application and consult a healthcare provider if the condition persists, worsens, or if a rash or allergic reaction develops.

For certain types of injuries, medical advice is required before using bacitracin ointment. These include:

• Deep or puncture wounds
• Animal bites
• Serious burns

The ointment should be stored at room temperature, away from excessive heat and moisture.