Ketek (telithromycin)

Ketek oral tablets contain telithromycin, a semisynthetic antibacterial in the ketolide class. The antibacterial kills many of the types of bacteria that can infect the lungs and sinuses, and has been found to treat these infections safely.The drug was designed to deliver targeted coverage in community-acquired upper and lower respiratory tract infections.

Ketek tablets are indicated for the treatment of infections caused by the following:

1. Acute bacterial exacerbation of chronic bronchitis due to Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis.
2. Acute bacterial sinusitis due to Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, or Staphylococcus aureus
3. Community-acquired pneumonia due to Streptococcus pneumoniae.

FDA approval of Ketek for the treatment of community-acquired pneumonia (CAP) was based on eight clinical trials enrolling a total of 2,016 subjects. These included four randomized, double-blind, controlled studies and four open-label studies. Results showed that of the 333 evaluable subjects with CAP due to Streptococcus pneumoniae, 312 or 93.7% achieved clinical success.

FDA approval of Ketek for the treatment of acute sinusitis was based on two randomized, double-blind, comparative studies. Results showed that subjects who received Ketek showed a clinical cure rate at post-therapy follow-up of 75.3% compared with 74.5% for subjects who received the comparator drug (amoxicillin/clavulanic acid). Data showed that subjects who received Ketek showed a clinical cure rate at post-therapy follow-up of 85.2% compared with 82.0% for subjects who received the comparator drug (cefuroxime axetil). A third study compared 5 days with 10 days of KETEK for the treatment of acute bacterial sinusitis, clinical cure rates for the two treatments were similar (91.1% vs. 91.0% respectively).

FDA approval of Ketek for the treatment exacerbation of chronic bronchitis was based on three randomized, double-blind, controlled studies. Results showed that subjects who received Ketek showed a clinical cure rate at post-therapy follow- up of 86.4% compared with 83.1% for subjects who received the comparator drug (cefuroxime axetil). Data showed that subjects who received Ketek showed a clinical cure rate at post-therapy follow- up of 86.1% compared with 82.1% for subjects who received the comparator drug (amoxicillin/clavulanic).

Adverse events associated with the use of Ketek may include (but are not limited to) the following:

• 
  
• Diarrhea
• Nausea
• Headache
• Dizziness
• Vomiting
• Loose Stools
• Dysgeusia

Telithromycin blocks protein synthesis by binding to domains II and V of 23S rRNA of the 50S ribosomal subunit. By binding at domain II, telithromycin retains activity against gram-positive cocci (e.g., Streptococcus pneumoniae) in the presence of resistance mediated by methylases (erm genes) that alter the domain V binding site of telithromycin. Telithromycin may also inhibit the assembly of nascent ribosomal units.

La Scola B, Bryskier A, Raoult D. Comparison of the in vitro efficacy of telithromycin (HMR 3647) and levofloxacin with 22 antibiotic compounds against Bosea and Afipia species. J Antimicrob Chemother. 2004 Apr; 53(4): 683-5.

Mathers Dunbar L, Hassman J, Tellier G. Efficacy and tolerability of once-daily oral telithromycin compared with clarithromycin for the treatment of community-acquired pneumonia in adults. Clin Ther. 2004 Jan; 26(1): 48-62.

Schito GC, Marchese A, Elkharrat D, Farrell DJ. Comparative activity of telithromycin against macrolide-resistant isolates of Streptococcus pneumoniae: results of two years of the PROTEKT surveillance study. J Chemother. 2004 Feb; 16(1): 13-22.

Nicolau DP. Clinical use of antimicrobial pharmacodynamic profiles to optimize treatment outcomes in community-acquired bacterial respiratory tract infections: application to telithromycin. Expert Opin Pharmacother. 2004 Feb; 5(2): 229-35.

For additional information regarding Ketek or Respiratory Infections, please contact The Ketek Web Site