Topical and Oral Antibiotics for Acne: Best Ones, How Long to Take Them, and More

• Antibiotics can kill acne-causing bacteria and reduce inflammation.
• Topical antibiotics are more effective in mild to moderate acne while oral antibiotics are used in more severe forms.
• Oral antibiotics can cause more side effects.
• Antibiotics should always be combined with other acne treatments.

Acne requires months and sometimes years of focused treatment, often with multiple medications. Since the role of bacteria in acne was discovered, antibiotics have been an important component in the management of acne. 

How Do Antibiotics Treat Acne? 

The role of bacteria in the development of acne vulgaris (or just acne) is well-established. Propionibacterium acnes (P. acnes; now renamed C. acnes) is a type of skin bacteria that can release enzymes that degrade surrounding oils and skin cells and trigger inflammation.

Antibiotics are medications with activity against bacteria; some antibiotics can directly kill bacteria and others work by stopping their growth and replication. In addition to fighting bacteria, many antibiotics also have anti-inflammatory effects.

Should you use antibiotics for acne?

The American Academy of Dermatology recommends antibiotics as part of the combination therapy for acne ranging from mild to severe. Antibiotics can target C. acnes on the skin and control inflammation, which can improve acne lesions. 

When combined with other acne oral medications or topical treatments with different mechanisms of action (e.g., benzoyl peroxide, isotretinoin, spironolactone, oral contraceptives), the effectiveness is greatly increased.

The main issue that is common to all antibiotics is the risk of bacterial antibiotic resistance. With prolonged use of antibiotics, bacteria can adapt and learn how to avoid destruction by the antibiotic. This makes the bacteria more aggressive and harder to kill. 

Strategies to reduce the risk of bacterial resistance include:

• Using the antibiotic consistently as prescribed
• Avoid overuse of antibiotics
• Using antibiotics with low rates of resistance
• Combining antibiotics with other acne medications

Tetracyclines can be dangerous to pregnant women and children under eight years of age. Avoiding these antibiotics in pregnancy and childhood is recommended.

Topical Antibiotics for Acne

Topical antibiotics typically work on mild acne but can also be part of the combination therapy for more severe types of acne. They come in the form of creams, gels, lotions, solutions, medicated wipes, and foams.

When applied topically, antibiotics accumulate in skin follicles where they can act against the bacteria and exert anti-inflammatory effects. 

Clindamycin and erythromycin are the most commonly used topical acne antibiotics. Other options include dapsone, minocycline, and sulfacetamide.

Clindamycin

Clindamycin is an antibiotic that works by stopping the multiplication of bacteria, effectively reducing their numbers. It also has anti-inflammatory properties.

Clindamycin is effective against mild to severe acne. It can reduce the severity and number of both inflammatory and noninflammatory acne lesions. When combined with other acne treatments such as benzoyl peroxide or retinoids, the improvements are even bigger.

Clindamycin is available as gels, foams, solutions, lotions, and medicated wipes or pledgets. The oral form of clindamycin is not used in the treatment of acne as it can cause diarrhea and inflammation of the colon.

Erythromycin 

Erythromycin belongs to the macrolide class of antibiotics, which work through a mechanism similar to clindamycin. 

Like clindamycin, erythromycin is recommended for mild, moderate, or severe acne in combination with other acne medications. Erythromycin and clindamycin are similarly effective.

Erythromycin is available as creams, gels, lotions, and pledgets. Unlike clindamycin, oral erythromycin can be used to treat acne.

Dapsone

Dapsone is effective at treating inflammatory and noninflammatory acne lesions, with inflammatory ones experiencing the biggest improvements. 

In two large-scale clinical trials, the number of inflammatory lesions in people treated with dapsone 5% gel fell by almost half (47.5%) after 12 weeks of treatment.

Topical dapsone 5% gel is recommended for inflammatory acne. Some studies suggest that it may be more effective in women.

Minocycline

Minocycline is a tetracycline antibiotic from the same family as doxycycline. It is typically used as an oral antibiotic for acne, but a new minocycline foam is expected to become available in 2020.

In clinical studies, this new formulation was effective in treating inflammatory and noninflammatory acne.

Sulfacetamide 

Although some studies suggest that sulfacetamide may be effective, there is not enough data to recommend its use in acne treatment. 

Oral Antibiotics for Acne

Oral or systemic antibiotics are first absorbed into your bloodstream then they diffuse through your skin to act against the bacteria. Due to the increased risk of side effects compared to topical antibiotics, they are reserved for more severe forms of acne.

Oral antibiotics should be combined with topical retinoids and benzoyl peroxide to increase effectiveness and decrease the risk of bacterial resistance.

Tetracyclines or macrolides are recommended in most people who require oral antibiotics.  

Tetracyclines

Tetracyclines are a class of antibiotics that work by inhibiting bacterial protein production, slowing down their growth and replication. 

Tetracyclines can treat moderate to severe inflammatory acne. This includes acne papules, pustules, nodules, and cysts. 

Doxycycline, one of the tetracyclines, is the first choice of oral antibiotic for acne. Oral minocycline is also effective but concerns over its side effects make it a less attractive option. The older drug tetracycline (named after the group) is no longer recommended for acne.

Sarecycline is a new tetracycline antibiotic that showed promise in treating moderate to severe acne. More studies are needed to compare the effectiveness and safety of sarecycline to other antibiotics.

Macrolides

Like tetracyclines, macrolides stop bacterial replication by interfering with protein production. The macrolides erythromycin and azithromycin are as effective in treating inflammatory acne as doxycycline.

Macrolides carry an increased risk of side effects and bacterial resistance. For this reason, their use is restricted to people who cannot take tetracyclines. This includes pregnant women and children under eight years of age.

Trimethoprim-sulfamethoxazole

Trimethoprim-sulfamethoxazole (TMP-SMX) is an effective treatment for severe acne. However, it can cause potentially severe side effects such as bone marrow suppression and toxic epidermal necrolysis, a condition in which the skin can slough off and resemble a severe burn.

The use of TMP-SMX is limited to patients who are unable to take other acne medications and when other treatments fail to improve the condition.

Amoxicillin

Amoxicillin is a derivative of the first antibiotic to be discovered, penicillin. It is effective in treating moderate to severe inflammatory acne and has a good safety profile.

In cases that do not respond to the usual acne medications or when other treatments cannot be used, particularly in pregnancy, amoxicillin can be used.

How Long Should You Take Antibiotics for Acne?  

While there is no hard limit on how long you can use antibiotics, their use should be limited to the shortest possible period to minimize the risk of developing bacterial resistance. Both topical and systemic antibiotics can cause resistance.

Antibiotics are typically prescribed for three to four months. Your dermatologist will then re-evaluate whether you need to continue taking them. Some people with extensive acne may need to use antibiotics for six months or longer.

It can take as little as two weeks after starting an antibiotic for you to see some improvements. Some people can take up to 12 weeks to experience improvements.

You should not stop or change the dosage of antibiotics without first consulting your dermatologist. Using antibiotics incorrectly can contribute to the development of bacterial resistance.

Side Effects

Depending on which antibiotic you use and whether you take it by mouth or use it topically, you may experience some side effects. Oral antibiotics generally cause more side effects than topicals.

The side effects of tetracyclines include nausea, vomiting, diarrhea, rash, esophagitis (inflammation of the esophagus), and photosensitivity (increased susceptibility to sunburns). They can also cause color changes in the skin and damage the bone and teeth of young children and infants whose mothers used tetracyclines while pregnant.

Macrolides can cause diarrhea, dizziness, jaundice, abnormal liver function tests, and electrocardiogram (ECG) changes.

Topical antibiotics can cause skin dryness, itching, redness, and exfoliation. 

Takeaway 

Antibiotics are a cornerstone of acne therapy. Oral and topical antibiotics are effective in treating inflammatory and noninflammatory acne. Because bacterial resistance is a concern with prolonged antibiotic use, they should be used for the shortest duration possible.