Antibiotic Therapy

1.2.1 Discuss the mechanism of action of penicillins, macrolides, quinolones, and aminoglycosides. What are some of the specific side-effects associated with each class of antibiotics? 

1.2.2 What are the classes of cephalosporins? Tell us which types of bacteria each class covers. Give examples of the different head and neck disease processes, in children and adults, each cephalosporin could be used to treat. 

• 1. First generation - cefazolin, cefadroxil, cephalexin, cephalothin, cephapirin, and cephradine.

     1. Good activity against aerobic gram-positive organisms (group A streptococcus, methicillin-sensitive S aureus, and viridans streptococci) and some community-acquired gram-negative organisms (Proteus mirabilis, E coli, and the Klebsiellaspecies). Agents in this class include the orally administered cephalexin (eg, Keflex) and the parenteral cefazolin (eg, Ancef).

     2. Commonly used for the treatment of minor staphylococcal infections such as in cellulitis. Intravenous first-generation cephalosporins are the drugs of choice for surgical prophylaxis in head and neck surgery if oral or pharyngeal mucosa is involved

  2. Second generation -

• • 1. cefuroxime (Zinacef), cefoxitin (Mefoxin), and cefotetan. In general, they provide slightly more gram-negative coverage than the first-generation cephalosporins, including activity against indole-positive Proteus, Klebsiella, M catarrhalis, and the Neisseria species. They have slightly less gram-positive activity than the first-generation cephalosporins. Cefoxitin and cefotetan also have activity against many strains of Bacteroide

    2. In patients with a mild allergy to ampicillin or amoxicillin, cefuroxime is an alternative agent for the treatment of sinusitis and otitis because it has activity against β-lactamase-producing strains such as H influenzae and M catarrhalis. Because of additional anaerobic activity, cefoxitin and cefotetan may be options for mixed (aerobic and anaerobic) infections of the head and neck.

• 3. Third generation

• • 1. Orally administered cefixime (Suprax), cefpodoxime (Vantin), and intravenously or intramuscularly administered ceftazidime (Fortaz), ceftriaxone (Rocephin), and cefotaxime. In general, these agents are less active against gram-positive organisms, including S aureus, but most streptococci are inhibited. Of these, ceftriaxone has the most reliable pneumococcal coverage. They all have expanded gram-negative coverage. Ceftazidime has good activity against Pseudomonas aeruginosa. Ceftriaxone is the first-line agent for gonorrhea. Cefixime and cefpodoxime are oral alternatives for gonorrhea.

    2. Because of their penetration into cerebrospinal fluid, third-generation cephalosporins are widely used to treat meningitis. Ceftriaxone can be used to treat meningitis caused by susceptible pneumococci, meningococci, H influenzae, and enteric gram-negative rods. It is also used for meningitis caused by the Pseudomonas species. Ceftriaxone, cefpodoxime, and cefixime are used for the treatment of gonorrhea, including pharyngeal disease.

• 4. Fourth generation

• • 1. Cefepime (Maxipime) is currently the only available fourth-generation cephalosporin. It has activity against Enterobacter, Citrobacter, and Pseudomonas species and similar activity to ceftriaxone against gram-positive organisms.

    2. Cefepime is typically used for gram-negative organisms resistant to other cephalosporins, such as Enterobacter and Citrobacter. It is also used empirically in patients with febrile neutropenia.

• 5. Fifth generation

• • 1. Ceftaroline (Teflaro). It has activity against gram-positive organisms, including methicillin-resistant S aureus, and gram-negative organisms with the notable exception of P aeruginosa.

    2. Ceftaroline can be used as an alternative agent for the treatment of skin and soft tissue infections, or community acquired pneumonia (MRSA +)

Reference:

-Bertrum K. Katzung et al. Basic and Clinical Pharmacology. 12 edition.

-Chin-Hong PV, Jacobs RA. Chapter 2. Antimicrobial Therapy for Head & Neck Infection. In: Lalwani AK. eds. CURRENT Diagnosis & Treatment in Otolaryngology—Head & Neck Surgery, 3e.  New York, NY: McGraw-Hill; 2012.

1.2.3 Unasyn-Why do we use it? What bacteria does it cover? What doesn’t it cover? What are your other option for a penicillin allergic patient?

1.2.4 A patient presents with an odontogenic neck abscess. What bugs are you concerned about? How would you cover?

1.2.5 Tell us about the normal flora of the upper aerodigestive tract.

1.2.6 What bacteria are you concerned about in pediatric acute and chronic otitis media? How will you cover and what are your choices?

1.2.7 What organisms are you concerned about in acute and chronic sinusitis? How will you cover and what are your choices? What bacteria should you be concerned about in patients with sinus disease and cystic fibrosis? Which types of antibiotics are most appropriate for this group of patients?

1.2.8 What are the different treatment options when managing otitis externa? Are there special considerations for diabetic and immunocompromised patients? 

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1.2.9 Fungal Infections: How do you treat fungal otitis externa?, Allergic fungal sinusitis?, Aspergilloma of the sinuses?, Invasive fungal sinusitis?

1.2.10 A patient presents with a post-traumatic CSF leak. Would you treat with antibiotics? What are the controversies regarding this? Does CSF otorrhea versus rhinorrhea influence your management?

1.2.11 Can you give penicillin allergic patients cephalosporins? What is the likelihood of an allergic reaction? How would you manage a patient that presents with an acute allergic reaction to an antibiotic?

1.2.12 Tell us about the bacteriology of necrotizing fasciitis. What is the appropriate treatment of patients with this disease process?

1.2.13 You pack a nose for epistaxis and fail to prescribe an antibiotic. Are antibiotics indicated? What would you use? What are the signs and symptoms of Toxic Shock Syndrome? Treatment of Toxic Shock?

1.2.14 Discuss the increasing incidence of Methicillin Resistant Staphylococcus Aureus (MRSA) in pediatric neck infections?. Which children are at risk? Which antibiotics should be utilized to treat pediatric patients with suspected MRSA neck abscess? Are these children at increased risk for complications?

Duggal P, Naseri I, Sobol SE. The increased risk of community-acquired methicillin-resistant Staphylococcus aureus neck abscesses in young children. Laryngoscope. 2011 Jan;121(1):51-5. PMID:21120830

1.2.15 Discuss the management of tympanostomy tube otorrhea. What is the first line treatment? Discuss patterns of bacterial resistance in patients with persistent otorrhea. What are some other antibiotic alternatives that can be utilized to treat such patients?

Oberman JP, Derkay CS. Posttympanostomy tube otorrhea. Am J Otolaryngol. 2004 Mar-Apr;25(2):110-7. PMID:14976657