Extended Spectrum Macrolide

Aka: Extended Spectrum Macrolide, Azithromycin, Zithromax, Clarithromycin, Biaxin, Telithromycin, Ketek

1. See also
   1. Erythromycin
2. Pharmacokinetics: Half Life
   1. Clarithromycin: 5 hours
   2. Telithromycin: 10 hours
   3. Azithromycin: 68 hours
3. Dosing: Azithromycin (Zithromax)
   1. Directions
      1. Take more than 1 hour before or 2 hours after food
      2. Adult
         1. Day 1: 500 mg PO qd
         2. Day 2 to 5: 250 mg PO qd
      3. Child
         1. Day 1: 10 mg/kg PO qd (maximum: 500 mg)
         2. Day 2 to 5: 5 mg/kg PO qd (maximum: 250 mg)
      4. Infant under age 6 months
         1. 10 mg/kg/day for 5 days
   2. New preparations
      1. ZMax 2 grams orally x1 dose (Available in 2005)
         1. For uncomplicated community acquired Pneumonia
         2. Vomiting >1 hour after dose - no additional med
         3. Use within 12 hours of reconstituting
      2. References
         1. (2005) Prescribers Letter 12(8):44
4. Dosing: Clarithromycin (Biaxin)
   1. May take with or without food
   2. Adult: 250 to 500 mg PO bid
   3. Child: 7.5 mg/kg PO bid
5. Dosing: Telithromycin
   1. Adult: 800 mg PO daily
   2. Course
      1. Acute Exacerbation of Chronic Bronchitis: 5 days
      2. Acute Sinusitis: 5 days
      3. Community acquired Pneumonia: 7 days
6. Adverse effects
   1. Less Nausea and Vomiting than with Erythromycin
   2. Clarithromycin perverts sense of taste in 20%
7. Indications: Major indications for newer broad spectrum Macrolides
   1. Erythromycin not tolerated
   2. Single dose Chlamydia trachomatis treatment
   3. Respiratory infections
      1. Otitis Media (Azithromycin)
      2. Community Acquired Pneumonia
         1. Consider Doxycycline as alternative
      3. Acute Sinusitis (Azithromycin)
         1. Not recommended due to growing resistance rates
      4. Non-tuberculous Mycobacterial infections
      5. Helicobacter infections
8. Contraindications
   1. Telithromycin (Ketek) may cause repiratory failure in Myasthenia Gravis (FDA Black Box Warning)
9. Preparations: Activity Spectrum
   1. Macrolide resistance is increasing
      1. Resistance to one Macrolide is resistance to all
   2. Spectrum includes organisms covered by Erythromycin
   3. Clarithromycin
      1. Streptococcus Pneumoniae (Pneumococcus)
      2. Staphylococcus aureus
      3. Toxoplasmosis gondii
      4. Mycobacterium leprae
      5. Mycobacterium Avium Complex
      6. Borrelia Burgdorferi
   4. Azithromycin
      1. HaemophilusInfluenzae
      2. Moraxella catarrhalis
      3. Toxoplasmosis gondii
      4. Mycobacterium Avium Complex (Clarithromycin better)
      5. Borrelia Burgdorferi
   5. Telithromycin
      1. Avoid in patients with Myasthenia Gravis due to risk of respiratory failure (FDA Black Box Warning)
      2. Similar to other Extended Spectrum Macrolides
      3. Appears to have greater activity for pneumococcus
      4. May be used in place of other broad spectrum agents
         1. Augmentin
         2. Extended spectrum Fluoroquinolones
      5. References
         1. Fogarty (2003) J Antimicrob Chemother 51:947-55