Telithromycin is an exogenous solid compound with the formula C43H65N5O10. Telithromycin belongs to the carbohydrates and carbohydrate conjugates, a subclass of organooxygen compounds within the organic compounds. With an average molecular weight of 812.00 g/mol, Telithromycin is a heavy molecule. It is found in healthcare, pharmaceuticals, and veterinary products, specifically among antibiotics and macrolides, lincosamides, and streptogramins. Recorded exposure routes include oral and inhalation.
This compound acts 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, such as Streptococcus pneumoniae, in the presence of resistance mediated by methylases (erm genes) that alter the domain V binding site. Additionally, telithromycin may inhibit the assembly of nascent ribosomal units. Its recorded protein targets include Cytochrome P450 3A7 (CYP3A7), Cytochrome P450 1A2 (CYP1A2), Cytochrome P450 3A4 (CYP3A4), Cytochrome P450 3A5 (CYP3A5), and one other protein. Telithromycin is used to treat mild to moderate respiratory infections by interfering with bacterial protein synthesis and blocking further peptide elongation.
Absolute bioavailability is approximately 57%. Maximal concentrations are reached 0.5 - 4 hours following oral administration. Food intake does not affected absorption.
Mechanism of Toxicity
Telithromycin acts 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. Compared to erythromycin A, telithromycin binds to the 23S rRNA with 10 times greater affinity in erythromycin-susceptible organisms and 25 times greater affinity in macrolide-resistant strains. This increased binding affinity may be conferred by the C11-12 carbamate side chain of telithromycin. The side chain appears to maintain binding at domain II in the presence of resistance mediated by alterations in domain V.
Metabolism
Hepatic - estimated 50% metabolized by CYP3A4 and 50% metabolized independent of cytochrome P450
Route of Elimination: The systemically available telithromycin is eliminated by multiple pathways as follows: 7% of the dose is excreted unchanged in feces by biliary and/or intestinal secretion; 13% of the dose is excreted unchanged in urine by renal excretion; and 37% of the dose is metabolized by the liver.
Half Life: Main elimination half-life is 2-3 hours; terminal elimination half-life is 10 hours
No indication of carcinogenicity to humans (not listed by IARC).
Uses/Sources
For the treatment of Pneumococcal infection, acute sinusitis, acute bacterial tonsillitis, acute bronchitis and bronchiolitis, lower respiratory tract infection and lobar (pneumococcal) pneumonia.
Minimum Risk Level
Not Available
Health Effects
Not Available
Symptoms
Most common side-effects are gastrointestinal, including diarrhea, nausea, abdominal pain and vomiting. Headache and disturbances in taste also occur. Less common side-effects include palpitations, blurred vision and rashes. [Wikipedia]
Suhas Sohani, Mandar Deodhar, Nishant Patel, Manish Patel, Mahesh Davadra, Vinodhamar Kansal, “Process for the Preparation of Telithromycin.” U.S. Patent US20070260066, issued November 08, 2007.
