Last reviewed 2026-04-20 · How we verify

Dirythromycin (DIRITHROMYCIN)

Dirithromycin is a marketed antibiotic primarily indicated for acute Moraxella catarrhalis bronchitis, positioned in a competitive landscape dominated by off-patent macrolides such as erythromycin, clarithromycin, and azithromycin. Its key strength lies in its mechanism of action, which effectively targets the 50S ribosomal subunit to inhibit bacterial protein synthesis, potentially offering a differentiated efficacy profile. The primary risk is the expiration of its key composition patent in 2028, which could lead to increased competition from generics.

At a glance

Approved indications

• Acute Moraxella catarrhalis bronchitis
• Acute bacterial bronchitis
• Bronchitis
• Haemophilus Influenzae Bronchitis
• Infection due to Staphylococcus aureus
• Infection of skin AND/OR subcutaneous tissue
• Legionella Pneumophila Pneumonia
• Pharyngitis
• Pneumonia
• Pneumonia due to Mycoplasma pneumoniae
• Pneumonia due to Streptococcus
• Streptococcal tonsillitis
• Streptococcus Pneumoniae Bronchitis
• Streptococcus pyogenes infection
• Tonsillitis

Common side effects

No common side effects on file.

Drug interactions

• ergotamine
• pimozide

Key clinical trials

• Patients Response to Early Switch To Oral:Osteomyelitis Study (EARLY_PHASE1)
• Semi-replicate Crossover Bioequivalence Study of Dirithromycin of (Abdi İbrahim İlaç San. Ve Tic. A. Ş., Turkey) in Healthy Subjects Under Fasting Conditions (PHASE1)
• Semi-replicate Crossover Bioequivalence Study of Dirithromycin in Healthy Subjects Under Fed Conditions (PHASE1)
• Bioequivalence Pilot Study of Dirithromycin of (Abdi İbrahim İlaç San.Ve.Tic.A.Ş,Turkey) in Healthy Subjects Under Fed Condition (PHASE1)
• Bioequivalence Pilot Study of Dirithromycin of (Abdi İbrahim İlaç San.Ve.Tic.A.Ş,Turkey) in Healthy Subjects Under Fasting Condition (PHASE1)

Primary sources

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