Answer
Caution is needed when Cialis (tadalafil) is used with ketoconazole because ketoconazole is a potent CYP3A4 inhibitor and increased tadalafil exposure (AUC) has been observed when they are combined.
Sources for this answer
- Cialis 2.5mg film-coated tabletsEli Lilly and Company Limited · emc · SmPC §4.4 Special warnings and precautions for use · Version 33Document updated
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