What Antibiotics Are Recommended To Treat Acute Bacterial Sinusitis In The Patient Who Had A Course Of Amoxicillin Within The Last Few Weeks For Otitis Media?
There are several possibilities that could explain the subsequent development of acute sinusitis after treatment with amoxicillin for acute otitis media (AOM). From a microbio- logic standpoint, the expected bacterial causes of acute sinusitis and AOM are known to be identical and so the recommended antibiotic therapy is similar. Thus, in this instance, the clinician must first be confident in the diagnosis of acute bacterial sinusitis because alternative diagnoses such as a viral upper respiratory infection (URI), which has similar symptoms to acute bacterial sinusitis, may be the actual cause of the infection. See the recent American Academy of Pediatrics (AAP) guidelines edited by Dr. Ellen Wald on the diagnosis of acute bacterial sinusitis. Note that green or yellow drainage occur with nearly every viral URI (usually on day 3 to 5 of drainage) and is not pathognomic or even highly suggestive of acute bacterial sinusitis. The discoloration of nasal drainage with viral URIs is due to increased cellular elements, including monocytes, macrophages, as well as neutrophils together with debris from injured or sloughed respiratory epithelium. Another noninfectious condition such as allergy is also very common and can present in a similar fashion. In the case of allergy, more detailed aspects of the patient history and additional symptoms such as itching in the nose or eyes may be a clue.
If the diagnostic certainty for acute bacterial sinusitis is high (eg, symptoms exceeding 10 days, or increasing in intensity after day 7 plus headache or facial or maxillary tooth pain), it is important to confirm that the duration and dosing of the prior amoxicillin was appropriate because inadequate treatment for AOM could predispose to subsequent sinusitis. This may occur if a persistent infection of the posterior nasopharynx occurs in the face of incompletely or inadequately treated AOM.
Another possible issue is whether the ostiomeatal complex became dysfunctional despite adequate AOM therapy during which the middle ear infection resolved. In other words, even though the initial infection was eradicated during the course of therapy, the sinuses may be unable to flush adequately and will become infected due to a mechanical problem. In this case, one may still select for amoxicillin resistance in the nasopharyngeal flora, which then enter the sinuses and cause infection. This has been well described for recurrent AOM, where Dagan et al showed that the longer the interval between episodes, the more likely the cause of a subsequent episode is a new pathogen. For example, if a recurrence occurs at 7 days, the chance that the original pathogen is the cause is approxi- mately 40%; this decreases to 25% after 2 weeks, 15% after 3 weeks, and 10% if 4 weeks has elapsed between episodes (Figure 36-1).
Figure 36-1. Proportion of AOM infections representing relapses vs. new infections over time.
In this context whereby one is considering the diagnosis of sinusitis following a recent episode of AOM, one must be concerned that the prior amoxicillin therapy has selected for a different pathogen including a highly penicillin-resistant pneumococcus or a beta- lactamase-producing pathogen such as nontypeable Haemophilus influenzae. In this case, using a beta-lactamase stable drug with as much pneumococcal activity as possible is the goal. High-dose amoxicillin plus clavulanate is an ideal choice as high-dose amoxicillin provides good coverage even for resistant strains of pneumococcus, and the clavulanate adds coverage for beta-lactamase-producing H influenzae and Moraxella catarrhalis. Both amoxicillin and amoxicillin with clavulanate are readily available at most pharmacies, come in several concentrations, and are palatable. “Other second-line alternatives to consider, especially in the case of penicillin allergy, include an oral third-generation cephalosporin, clindamycin, and azithromycin. Some clinicians ask, “What is the highest dose of amoxicillin that can be used?” My answer is 100 mg/kg/d or up to 4 g/d of amoxicil- lin. Although this is not technically Food and Drug Administration approved as a sole product, this dose is FDA approved for Augmentin XR. If the pharmacist questions your prescribing 4 g/d, you can refer them to the package insert for Augmentin XR.
The optimal duration of therapy for acute sinusitis is not well established, but 10 days has been effective in several clinical trials. There are data in adult-based studies that have shown effective treatment in as little as 3 days. However, this has not been established in children.
American Academy of Pediatrics Subcommittee on Management of Acute Otitis Media. Diagnosis and management of acute otitis media. Pediatrics. 2004;113(5):1451-1465.
Leibovitz E, Greenberg D, Piglansky L, et al. Recurrent acute otitis media occurring within one month from comple- tion of antibiotic therapy: relationship to the original pathogen. Pediatr Infect Dis J. 2003;22(3):209-216 (ISSN:0891-3668).