- Regular or chronic treatment with strong inhibitors of Cytochrome P450 (CYP) 3A4 and/or CYP2D6 (this includes some anti-epileptic treatments, macrolide antibiotics, oral antifungal treatments and anti-tuberculosis therapy are prohibited from the screening visit until the end of treatment visit. Where clinically appropriate, an alternative drug in the same class (or unrelated class) that is not a strong CYP3A4 and/or CYP2D6 inhibitor can, after signing informed consent, be substituted for the original strong inhibitor of these enzymes