A number of different antibiotics are available
Antibiotics work by controlling the skin bacteria (P. acnes) that contributes to acne. They also have an anti-inflammatory action, which can reduce the redness, swelling and pain.
Antibiotics are used for inflammatory acne – small pink lumps and bumps and pustules. In more serious cases the lumps are larger and may appear as nodules and cysts.
Antibiotics have been used in acne management for decades, however with increasing concerns of antibiotic resistance there is a trend to use shorter courses, usually three to six months of treatment. Using antibiotics with topical benzoyl peroxide can reduce bacterial resistance.
Antibiotic gels and lotions are applied directly onto the skin (e.g. Aczone, Clindatech and Dalacin). Those currently used for the treatment of acne contain the active ingredients clindamycin or dapsone. You should use these on a cool, dry face to minimise irritation.
Using topical antibiotics avoids some side effects that may occur with oral antibiotics, however they may take longer to be effective. Larger areas over the back may be difficult to reach to get a good application.
There is also a combination product (Duac gel) that combines clindamycin and benzoyl peroxide.
Antibiotic tablets/capsules include doxycycline (e.g. Doxy, Doryx, Vibratabs), minocycline (eg, Minomycin, Akamin) and trimethoprim. Erythromycin may be used in younger patients and pregnancy. Bactrim is a sulfa antibiotic and is used occasionally.
A number of different antibiotics are available and a doctor will recommend the most suitable product for you. If one antibiotic doesn’t improve your acne, your doctor may change your dose or change you to a different one to improve effectiveness.
How to use antibiotics
A doctor will prescribe an antibiotic gel, solution or lotion with instructions on how often to apply it, which parts of the skin it should be put on, and for how long. Follow these instructions carefully. Other treatments (e.g. topical benzoyl peroxide or retinoids such as Epiduo) are often prescribed in association with antibiotics to obtain maximum benefit.
In most cases you should apply a thin smear once or twice a day to the entire area affected by acne, not just the spots. This is because topical preparations work to reduce visible pimples but also help prevent new ones. Using them regularly over the entire area will lead to much better control of acne.
Oral antibiotics may work faster and tend to be more effective if large areas are involved, such as acne on the face and body.
Your doctor and pharmacist will tell you when it’s best to take tablets or capsules and whether or not they should be taken with food. They can also provide some practical tips on how to remember to take medications.
Antibiotics usually produce some improvement in 6-12 weeks. Talk to your doctor if your acne is not settling down within this timeframe.
Reduce the risks
Over the years, antibiotics have saved millions of lives but like all medications, there can be side effects.
Doxycycline can increase sensitivity to the sun so it’s best to take extra precautions to avoid sunburn:
- Avoid being in the sun when the UV alert is above level 3. This is usually in the middle of the day, particularly in summer. Check the Bureau of Meteorology or Sunsmart websites or download the free Sunsmart App to have a daily alert sent to you
- Stay in the shade whenever possible
- Wear a hat and other physical protection such as rash shirts at the beach
- Use sunscreen (labelled non-comedogenic and/or non-acnegenic) regularly
Potential side effects
Nausea, diarrhoea and thrush may affect a small number of people taking oral antibiotics.
In some cases the antibiotics used to treat acne may cause headaches. If you think any medications are causing headaches, particularly if they are present in the morning, not quickly relieved with paracetamol and/or associated with blurring of vision or neck stiffness, you should stop the medication and see your doctor.
Antibiotics can sometimes cause an allergy. Allergic reactions are more common with minocycline, rare with doxycycline and uncommon with antibiotic gels, solution and lotions. Anyone with the warning signs or symptoms of allergy including an unexplained fever, sore throat, swollen neck glands and rash should stop the medication and visit the doctor. Other symptoms can include joint pain and swelling, nausea, abdominal discomfort, diarrhoea, headache and shortness of breath.
Occasionally fever, rash, joint swelling and pain, skin ulcers and generally feeling unwell due to minocycline allergy can occur several years after first starting therapy.
Uncommonly, topical antibiotic gels and lotions may cause an irritation or allergic contact dermatitis. Using it together with other acne treatments may increase irritation so it’s best to see your doctor for advice on how to reduce irritation with these medications.
As with all antibiotics, there is concern that if they are over-used or inappropriately used, strains of the acne bacteria will become resistant to antibiotics, making the medications ineffective. Taking antibiotics for the full course as prescribed and applying antibiotic creams and gels as directed will reduce this risk.
Combining antibiotic therapy with other acne treatments e.g. benzoyl peroxide cream or wash also helps to protect against antibiotic resistance.