Antibiotics, Topical

Antibiotics, topical

Definition

Topical antibiotics are medicines applied to the skin to kill or stop the growth of bacteria.

Purpose

Topical antibiotics help prevent infections caused by bacteria that get into minor cuts, scrapes, and burns. Treating minor wounds with antibiotics allows quicker healing. If the wounds are left untreated, the bacteria will multiply, causing pain, redness, swelling, itching, and oozing. Untreated infections can eventually spread and become much more serious.

Topical antibiotics may also be applied to surgical incision sites to prevent infection. However, when antibiotics are given intravenously (by vein) or during surgery and intravenously or by mouth following surgery, this may be enough to prevent infection, and antibiotic ointments may not be needed.

Different kinds of topical antibiotics kill different kinds of bacteria. Many antibiotic first-aid products contain combinations of antibiotics to make them effective against a broad range of bacteria.

When treating a wound, it is not enough to simply apply a topical antibiotic. The wound must first be cleaned with soap and water and patted dry. After the antibiotic is applied, the wound should be covered with a dressing such as a bandage or a protective gel or spray. For many years, it was thought that wounds heal best when exposed to the air. But now most experts say it is best to keep wounds clean and moist while they heal. The covering should still allow some air to reach the wound, however.

Description

Some topical antibiotics are available without a prescription and are sold in many forms, including creams, ointments, powders, and sprays. Some widely used topical antibiotics are bacitracin, neomycin, mupirocin, and polymyxin B. Among the products that contain one or more of these ingredients are Bactroban (a prescription item), Neosporin, Polysporin, and Triple Antibiotic Ointment or Cream.

Recommended dosage

The recommended dosage depends on the type of topical antibiotic. The patient is advised to follow the directions on the package label or ask a pharmacist for directions.

Because only the ointment or cream that actually touches the skin has any benefit, a thin layer of topical antibiotic ointment or cream will usually work just as well as a thick layer.

In general, topical antibiotics should be applied within four hours after injury. It is advised not to use more than the recommended amount and do not apply it more often than three times a day; the medicine should not be applied over large areas of skin or on open wounds.

When topical antibiotics are used for surgical incision sites, a surgeon or nurse should be consulted for instructions.

Precautions

Many public health experts are concerned about antibiotic resistance, a problem that can develop when antibiotics are overused. Over time, bacteria develop new defenses against the antibiotics that once were effective against them. Because bacteria reproduce so quickly, these defenses can be rapidly passed on through generations of bacteria until almost all are immune to the effects of a particular antibiotic. The process happens faster than new antibiotics can be developed. To help control the problem, many experts advise people to use topical antibiotics only for short periods, that is, until the wound heals, and only as directed. For the topical antibiotic to work best, it should be used only to prevent infection in a fresh wound, not to treat an infection that has already started. Wounds that are not fresh may need the attention of a physician to prevent complications such as blood poisoning.

Topical antibiotics are meant to be used only on the skin and for only a few days at a time. If the wound has not healed in five days, the patient is advised to stop using the antibiotic and call a doctor.

It is advised not to use topical antibiotics on large areas of skin or on open wounds. These products should not be used to treat diaper rash in infants or incontinence rash in adults.

Only minor cuts, scrapes, and burns should be treated with topical antibiotics. Certain kinds of injuries may need medical care and should not be self-treated with topical antibiotics. These include:

• large wounds
• deep cuts
• cuts that continue bleeding
• cuts that may need stitches
• burns any larger than a few inches in diameter
• scrapes imbedded with particles that will not wash away
• animal bites
• deep puncture wounds
• eye injuries

Regular topical antibiotics should never be used in the eyes. Special antibiotic products are available for treating eye infections.

Although topical antibiotics control infections caused by bacteria, they may allow fungal infections to develop. The use of other medicines to treat the fungal infections may be necessary. It is recommended to check with the physician.

Some people may be allergic to one or more ingredients in a topical antibiotic product. If an allergic reaction develops, the person should stop using the product immediately and call a physician.

No harmful or abnormal effects have been reported in babies whose mothers used topical antibiotics while pregnant or nursing. However, pregnant women generally are advised not to use any drugs during the first three months after conception. A woman who is pregnant or breastfeeding or who plans to become pregnant should check with her physician before using a topical antibiotic.

Unless a physician says to do so, topical antibiotics should not be used on children under two years of age.

Side effects

The most common minor side effects are itching or burning. These problems usually do not require medical treatment unless they do not go away or they interfere with normal activities.

If any of the following side effects occur, a doctor should be consulted as soon as possible:

• rash
• swelling of the lips and face
• sweating
• tightness or discomfort in the chest
• breathing problems
• fainting or dizziness
• low blood pressure
• nausea
• diarrhea
• hearing loss or ringing in the ears

Other rare side effects may occur. Anyone who has unusual symptoms after using a topical antibiotic should get in touch with the physician who prescribed it or the pharmacist who recommended the medication.

Interactions

Using certain topical antibiotics at the same time as hydrocortisone (a topical corticosteroid used to treat inflammation) may hide signs of infection or allergic reaction. These two medicines should not be used at the same time unless recommended by a health care provider.

Anyone who is using any other type of prescription or nonprescription (over-the-counter) medicine on the skin should check with a doctor before using a topical antibiotic.

Resources

periodicals

Farley, Dixie. "Help for Cuts, Scrapes and Burns." FDA Consumer (May 1996): 12.

O'Connor, L.T. Jr., and M. Goldstein. "Topical Perioperative Antibiotic Prophylaxis for Minor Clean Inguinal Surgery." Journal of the American College of Surgeons 194, no. 4 (April 2002): 407–10.

Nancy Ross-Flanigan Sam Uretsky