Telithromycin is a ketolide, an erythromycin derivative with improved acid stability and tissue penetration. It is used in community-acquired pneumonia, including drug-resistant pathogens.
Also known as: Ketek
Ketolide + statin: severe risk of myopathy/rhabdomyolysis. Telithromycin inhibits CYP3A4, increasing simvastatin levels ~10-fold.
Telithromycin moderately inhibits CYP3A4, the main metabolic pathway for simvastatin. Increased simvastatin levels can cause severe myopathy with rhabdomyolysis. The combination is clinically significant and should be avoided.
Creatine kinase (CK), myopathy symptoms (muscle pain, weakness, dark urine).
Avoid coadministration. If unavoidable, discontinue simvastatin during telithromycin treatment. Alternative: pravastatin (not CYP3A4-metabolised).
DailyMed/FDA (NIH/NLM) — approved Telithromycin label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=ba1cca98-f350-4655-88e3-6ef990779fb9
Ketolide + anticoagulant: warfarin potentiated via CYP2C9 inhibition. Risk of serious haemorrhage.
Telithromycin inhibits CYP2C9, the main metabolic enzyme for warfarin (S-enantiomer, more potent). Studies show 2-3-fold INR increase. The risk of haemorrhage is significant.
Daily INR, signs of bleeding (bruising, haematuria, melaena).
Avoid combination if possible. If necessary, reduce warfarin dose 25-50% and monitor INR daily during and 1 week after antibiotic therapy.
DailyMed/FDA (NIH/NLM) — approved Telithromycin label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=ba1cca98-f350-4655-88e3-6ef990779fb9
No documented food or drink interactions.
No documented disease interactions.
CONTRAINDICATED in pregnancy. Fetal toxicity (embryonic loss, developmental delay).
All trimesters: CONTRAINDICATED.
CONTRAINDICATED during breastfeeding.
Inadequate data on human fertility.
DailyMed/FDA (NIH/NLM) — approved Telithromycin label: https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=ba1cca98-f350-4655-88e3-6ef990779fb9
Clinical and educational support tool. The information does not replace a medical prescription or the opinion of a qualified healthcare professional.
Bactericidal: inhibits bacterial protein synthesis via dual binding to the ribosome (23S rRNA). Activity against macrolide-resistant S. pneumoniae, H. influenzae, M. catarrhalis, Legionella, Chlamydophila.
Binds to two sites on the 50S ribosomal subunit 23S (unlike macrolides which bind one). This dual binding maintains activity against erm-methylated strains (macrolide resistance). Bactericidal against S. pneumoniae.
Oral absorption: ~57%, not food-influenced. Peaks at 1 h. Good penetration into alveolar cells and tonsillar tissue.
Hepatic metabolism via CYP3A4 (partial) and N-oxide demethylation. Inhibits CYP3A4 (weak to moderate). Less active metabolites.
10 h (normal renal function). No adjustment required in renal impairment.
Medicines from the same therapeutic group (ATC classification) or the same pharmacological class.
