Patients are often surprised that the antibiotics that we use are really not used as antibiotics--in that acne is not an infection. You can't pass on acne from one person to another. So, yes, the antibiotics that we use may indeed suppress and they do reduce the bacterial called P. Acnes. It doesn't seem to be the main part of how they work.
The antibiotics that we use are also anti-inflammatories. They reduce the ability of the white cells to get into the skin. They reduce the inflammatory part of acne. It's important to know that they work in two ways: The anti-inflammatory and maybe some of it is antibacterial.
They act slowly. The response to these is not as if you had a sore throat from strep, and you take an antibiotic for a week, you kill off the bacteria and that's it. In acne, they work very slowly-you expect maybe a 50% improvement in the number of inflammatories: less pimples pustules. 50% in 12 weeks.
The philosophy I think has changed from 20 years ago. Individuals were put on antibiotics such as tetracycline and left for a long time. We are now living in a world of antibiotic resistance, and there is an awareness that maybe it's not such a smart thing to be using these antibiotics for a very long time. There is concern about antibiotic resistance not just to bacteria in the skin but bacteria in the gut and transferring resistance.
I think, the approach of many including myself, is to use the oral antibiotics as short a time as possible to try and reduce the amount of inflammation, get improvement in the acne as quickly as you can. It helps compliance-even if it responds quickly, it's a long time. We use the antibiotics for 2 or 3 months, and then hope that topical medications that we have can keep the acne down after the initial injection of the anti-inflammatory antibiotics by mouth.
That's been an evolution in the way that we think about these antibiotics. It does appear that if you add a topical Benzoyl peroxide, say a Benzoyl peroxide wash on to the skin, when you're on an oral antibiotic, it may reduce the selection of resistant organisms.
Whenever you use an antibiotic or any drug for a long time, you always have to balance the advantages to the side effects. Various antibiotics have different types of side effects, different things that we have to consider when prescribing them, and it's our responsibility to keep the patient safe. Antibiotics are useful, yes. If there were better treatments, we'd use them.