Chapter 128. Pneumococcal Infections (Part 8) pot

Chapter 128. Pneumococcal Infections (Part 8) Acute Sinusitis Just as the pathogenesis and microbial etiology of acute rhinosinusitis are similar to those of otitis media, so are the principles of diagnosis and treatment. The diagnosis is often empirical, and the less rigorously it is made, the more irrelevant antibiotics are likely to be. The estimated efficacy rate for amoxicillin/clavulanic acid, fluoroquinolones, and ceftriaxone (available for parenteral use only) is 90–92%, as opposed to 83–88% for amoxicillin, trimethoprim-sulfamethoxazole, and oral second- or third-generation cephalosporins and 71–81% for macrolides and doxycycline. Treatment should be given for longer periods than are recommended for otitis media (perhaps 10–14 days), but the optimal duration is uncertain. Pneumonia (Table 128-5) This section will deal primarily with the treatment of pneumococcal pneumonia. The broader issue of empirical therapy for community- acquired pneumonia is covered elsewhere (Chap. 251). Unless epidemiologic, clinical, and radiologic findings strongly favor another etiology, empirical therapy for pneumonia must include an agent that will be effective against S. pneumoniae, which remains the most likely causative agent of community-acquired pneumonia. Table 128- 5 Regimens for the Treatment of Pneumococcal Pneumonia in Adults a Route, Drug Dose, Schedule b Oral Therapy Amoxicillin 1 g q8h Quinolone, e.g., levofloxacin 500 mg q24h Telithromycin 800 mg q24h Parenteral Therapy Penicillin c 3–4 mU q4h Ampicillin 1–2 g q6h Ceftriaxone 1 g q12–24h Cefotaxime 1–2 g q6–8h Quinolone, e.g., gatifloxacin 400 mg q24h Imipenem 500 mg q6h Vancomycin d 500 mg q6h a These regimens are recommended for treatment after a presumptive diagnosis of pneumoco ccal pneumonia is made on the basis of examination of a Gram- stained sputum sample or as a replacement for broader spectrum empirical therapy after a diagnosis of pneumococcal pneumonia is proven by culture. When a valid sputum specimen cannot be obtained, concern about other likely pathogens should prompt the selection of more all- inclusive therapeutic regimens. Readers are referred to guidelines for empirical treatment of community- acquired pneumonia. b Therapy should continue for 5 days after defervescence, not to exceed 7– 10 days total. A switch from parenteral to oral drug administration may be made as soon as the patient can tolerate oral medications. c This regimen is listed more for historic than for practical reasons. The spectrum is overly narrow, although perfectly acceptable if a Gram- stained sputum specimen shows only pneumococci. However, the need for frequent administration, mandated by the short half- life of penicillin, renders this regimen impractical. d Not proven to be effective by the extensi ve clinical experience that applies to the other regimens. Outpatient Therapy Amoxicillin (1 g three times daily) effectively treats virtually all cases of pneumococcal pneumonia. Neither cefuroxime nor cefpodoxime offers any advantages over amoxicillin, and they are far more expensive. Telithromycin is likely to be equally effective. Moxifloxacin is also highly likely to be effective in the United States except in patients who come from a closed population where these drugs are used widely or who have themselves been treated recently with a quinolone. Clindamycin is effective in 90% of cases and doxycycline, azithromycin, or clarithromycin in 80%. Treatment failure resulting in bacteremic disease due to macrolide-resistant isolates has been amply documented in patients treated empirically with azithromycin. As noted above, rates of resistance to all these antibiotics are lower in some countries and much higher in others; high-dose amoxicillin remains the best option worldwide. . Chapter 128. Pneumococcal Infections (Part 8) Acute Sinusitis Just as the pathogenesis and microbial etiology of. days), but the optimal duration is uncertain. Pneumonia (Table 128- 5) This section will deal primarily with the treatment of pneumococcal pneumonia. The broader issue of empirical therapy for. remains the most likely causative agent of community-acquired pneumonia. Table 128- 5 Regimens for the Treatment of Pneumococcal Pneumonia in Adults a Route, Drug Dose, Schedule b Oral