Hypersensitivity to the active substance or to any of the excipients (see Excipient/Inactive Ingredient under Description).
During breast-feeding.
Severe hepatic impairment (serum bilirubin > 3.0 mg/dL).
Jaundice.
Severe bone marrow suppression and severe blood count alterations (leukocyte and/or platelet values dropped to < 3000/μL or < 75000/μL, respectively).
Major surgery less than 30 days before start of treatment.
Infections, especially involving leukocytopenia.
Yellow fever vaccination.