Focusing on the treatment landscape of acute bacterial skin and skin structure infections (ABSSSIs), key opinion leaders discuss duration of therapy and the current role of vancomycin in this setting.
Joe Reilly, PharmD, BS, BCGP: The duration of therapy for the treatment of skin infections is typically 7 to 14 days. Depending on the setting, if they’re treated in the outpatient setting, it would be all oral therapy. If it’s in the hospital, that’s where we can run into problems because you’re admitted to the hospital to treat these patients. Let’s say they need 10 days of therapy. The goal is to get them out as quickly as possible. So when we get them out on day 4, if that’s the average length of stay in a hospital, or day 5, we have to switch them to continuing therapy in the outpatient setting. And is that going to be parenteral therapy, is that going to be oral antibiotics? Many of these patients are admitted through a hospital, not because they necessarily need an IV [intravenous antibiotic] for clinical reasons; they need an IV because they’re deemed 'not going to be compliant with oral antibiotics.'
So we admit them, and we try to get them out on day 4, which is still a money-losing situation, switch them to oral antibiotics, and then they may not be compliant. So 7 to 14 days of treatment that may vary depending on the size of the infection, the severity of it, comorbidities, whether the patient is immunocompromised, how they present it, whether it’s uncomplicated or complicated. And we just hope that they can take all their antibiotics.
Tom Lodise, PharmD, PhD: Yes. And I think Joe is right. I think a good rule of thumb is probably 7 to 10 days. Historically, we used to treat for 2 weeks and, in some cases, longer. And I think one of the themes in infectious diseases right now is 'Treat them hard, treat them early, and treat them as short as possible.' For CAP [community-acquired pneumonia] or even hospital acquired pneumonia, we have that, and a responding patient who gets early appropriate therapy, we could treat 5 to 7 days. And even across recent abscesses studies, we’re showing that 5 to 7 days is as good as 10.
There are a couple of things when we think about these shorter-course therapies. It’s in a setting where the patient has adequate surgical intervention; they’re responding. And in that scenario, I think 5 or 7 days is fine. But I don’t know about you, Joe, but most of our patients are a bit more complicated than that. And I think what we often find is they take them a few days to respond. Again, you’re always going to have that inflammation post antibiotics, but they still do not feel well; they have that postinflammatory response. So I think in most individuals that we see and do hospitalize, I think 7 to 10 days is more the rule, and it’s really that window post discharge I’m a bit worried about for all the reasons that Joe mentioned.
Joe Reilly, PharmD, BS, BCGP: I couldn’t agree more. You have to think about the fact that there’s a selection bias—sort of who actually goes to the emergency department [ED] with a skin infection. A lot of times, they didn’t have a scratch, and then 24 hours later, it’s a fulminant infection because it’s something that’s been developing. So maybe they ignored it. Many people would just go to their primary care doctor, but these patients are presenting with the ED now for treatment. And I think that lends itself to mean that they may not necessarily be compliant with their medical care or stay compliant with their antibiotic therapy.
So a lot of these patients may have a little bit more advanced infections, even if they’re stable and they don’t have complications, but the wounds can be larger or the abscess can be a little bit bigger. And we admit them, and the goal is they get IV antibiotics, but in order even to break even based on our reimbursement—if we’re getting reimbursed for this by Medicare, say $5000 is an average reimbursement, about that—we have to get them out of the hospital within 3 days even to break even. And most of that cost is your room and board. So the treatment paradigm is difficult.
Tom Lodise, PharmD, PhD: Is vancomycin the most commonly used antimicrobial for skin? The answer is yes. We still use a lot of vancomycin. There have been some recent prevalence studies showing it’s the No. 1 prescribed drug for skin and soft tissue infections. This is true in the inpatient setting, which may surprise many of us because vancomycin, because of the therapeutic drug monitoring and multiple daily dosing, is also on one of the No. 1 prescribed drugs in OPAT [outpatient parenteral antimicrobial therapy] as an IV administration. Still use a lot of vancomycin. I kind of view it as a dog with fleas. Monitoring, multiple dosing, we start running into toxicity, particularly nephrotoxicity with prolonged use. But despite all these things, it’s still our primary agent.
Joe Reilly, PharmD, BS, BCGP: Back to cost, a lot of people will go with vancomycin. It makes sense for them, and you think, 'Well, it’s a relatively inexpensive antibiotic. Why would I want to use something more expensive?' But you really have to look at all the costs that are incurred. And the costs that may be incurred by therapeutic drug monitoring, checking the levels, the potential risk of nephrotoxicity and what that may cost for patients. So most institutions will use a lot of vancomycin. I think that decision is based mostly on acquisition cost because it’s deemed relatively cheap. And that sort of silo mentality, just thinking about the acquisition cost of the drug, can lead to problems for sure.