Chemical structure of telithromycin.
Find information on thousands of medical conditions and prescription drugs.

Ketek

Telithromycin is the first ketolide antibiotic to enter clinical use. It is used to treat mild to moderate respiratory infections. Telithromycin is sold under the brand name of Ketek. more...

Home
Diseases
Medicines
A
B
C
D
E
F
G
H
I
J
K
Clonazepam
K-Dur
Kadian
Kainic acid
Kanamycin
Kantrex
Kariva
Kayexalate
Keflex
Kefzol
Kemstro
Keppra
Ketalar
Ketamine
Ketanserin
Ketek
Ketoconazole
Ketoprofen
Ketorolac
Ketotifen
Kionex
Klor-con
Klotrix
Konazol
Korostatin
Kytril
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z

Telithromycin is a semi-synthetic erythromycin derivative. It is created by substituting the cladinose sugar with a ketogroup and adding a carbamate ring in the lactone ring. An alkyl-aryl moiety is attached to this carbamate ring. Furthermore, the carbon at position 6 has been methylated, like in clarithromycin, to achieve better acid-stability.

History

French pharmaceutical company Hoechst Marion Roussel (later Aventis) started phase II/III trials of telithromycin (HMR-3647) in 1998. Telithromycin was approved by the European Commission in July 2001 and subsequently came on sale in October 2001. In USA, telithromycin gained FDA approval April 1, 2004 .

Available forms

Telithromycin is administered as tablets. Two 400mg tablets to be taken together, daily, with or without food.

Mechanism of action

Telithromycin prevents bacteria from growing, by interfering with their protein synthesis. Telithromycin binds to the subunit 50S of the bacterial ribosome, and thus inhibits the translocation of peptides. Telithromycin has over 10 times higher affinity to the subunit 50S than erythromycin. In addition, telithromycin binds simultaneously in to two domains of 23S RNA of the ribosomal subunit 50S, where older macrolides bind only in one. Telithromycin can also inhibit the formation of ribosomal subunits 50S and 30S.

Pharmacokinetics

Unlike erythromycin, telithromycin is acid-stable and can therefore be taken orally without being protected from gastric acids. It is fairly rapidly absorbed, and diffused into most tissues and phagocytes. Due to the high concentration in phagocytes, telithromycin is actively transported to the site of infection. During active phagocytosis, large concentrations of telithromycin is released. The concentration of telithromycin in the tissues much higher than in plasma.

Metabolism

It is metabolized mainly in the liver, the main elimination route being the bile, a small portion is also excreted into the urine. About one third is excreted unchanged into the bile and urine, the biliary route being favoured. Telithromycin's half-life is approximately 10 hours.so

Side effects

Most common side-effects are gastrointestinal; diarrhoea, nausea, abdominal pain and vomiting. Headache and disturbances in taste also occur. Less common side-effects include palpitations, blurred vision and rashes.

Rare, but severe side effects reported in January 2006 involve damage to the liver. Three different incidents reported, one ending in death, one in a liver transplant and one case of drug induced hepatitis.

Has been known to cause false positive readings in drug screenings for cocaine and amphetamines.

Read more at Wikipedia.org


[List your site here Free!]


Antibiotic choice makes little difference in CAP
From Journal of Family Practice, 6/1/05 by G.D. Mills

Mills GD, Oehley MR, Arrol B. Effectiveness of beta lactam antibiotics compared with antibiotics active against atypical pathogens in non-severe community acquired pneumonia: meta-analysis. BMJ 2005; 330:456-460.

* Clinical Question

In the treatment of patients with community-acquired pneumonia, is there a difference among antibiotics?

* Bottom Line

Strange, but true: Oral beta-lactam antibiotics--amoxicillin, amoxicillin/clavulanate (Augmentin), or a cephalosporin--are as effective in the treatment of community-acquired pneumonia as antibiotics active against atypical pathogens, even in patients infected with Mycoplasma pneumoniae or Chlamydia pneumoniae. These old standbys can be used instead of the more expensive drugs for most patients.

Legionella infection still requires treatment with an antibiotic effective against atypical pathogens, but in these studies only 1.1% of the patients with nonsevere pneumonia had Legionella. These results are backed up by similar findings from clinical practice (Hedlund J, et al. Scand J Infect Dis 2002; 34:887-892). (LOE=1a)

Study Design

Meta-analysis (randomized controlled trials)

Setting

Various (meta-analysis)

Synopsis

We have to treat some patients with community-acquired pneumonia (CAP) for atypical bacteria, just in case, don't we? This question was answered by the authors of this meta-analysis. They identified 18 studies comparing a beta-lactam antibiotic with an antibiotic active against the atypical pathogens M pneumoniae, Legionella species, and C pneumoniae: macrolides, fluoroquinolones, or ketolides (eg, telithromycin [Ketek]). They used rigorous methods to identify the studies, searching 3 databases for articles published in any language, searching the reference lists of review articles and retrieved studies, and including unpublished research conducted by pharmaceutical companies. Two reviewers independently screened the studies for inclusion. On average, the 6749 patients in the clinical trials were younger than the typical patient with pneumonia (in most studies the average age was between 40 and 55 years) and had a better risk profile.

Neither macrolides, ketolides, or fluoroquinolones were superior to beta-lactam antibiotics. When analyzed separately by type of antibiotic, neither macrolides nor fluoroquinolones were superior, either with regard to cure or mortality rates at the time specified in the study, usually end of treatment or at 10 days. The speed of response, relapse, or length of stay were not compared.

Here's a surprising outcome: There was no difference between beta-lactams and the other drugs in patients who had M pneumoniae or C pneumoniae. The numbers of patients in these subgroups was small: 211 patients had Mycoplasma infections and 115 had Chlamydia infections. The antibiotics active against atypical pathogens were significantly better at producing clinical cures in the treatment of 75 patients with Legionella (relative risk=0.4; 95% CI, 0.19-0.85).

The investigators used a combined endpoint of success, including cure of pneumonia, absence of adverse drug reactions, absence of medical complications, no need for additional visits, no changes in initial treatment, and no hospital admission or death within 30 days. This outcome was achieved by 83.6% of outpatients and 80.7% of hospitalized patients. Readmission rates were similar in the 2 groups (6%-7%). Health-related quality-of-life scores measured at 7 and 30 days were similar in both groups. More outpatients than inpatients reported satisfaction with their overall care (91.2% vs 79.1%; P=.03).

COPYRIGHT 2005 Dowden Health Media, Inc.
COPYRIGHT 2005 Gale Group

Return to Ketek
Home Contact Resources Exchange Links ebay