Cyclophosphamide Aprepitant

Moderate Anthracydine + cyclophosphamide SSRI (as above) and Dexamethasone 12 mg po (with aprepitant) and Aprepitant 125 mg po Aprepitant 80 mg po days 2 and 3... 

Aprepitant had no effect on the pharmacokinetics of a single dose of docetaxeL The activation of cyclophosphamide and thiotepa was slightly lower in patients receiving aprepitant, but this was not clinically relevant. However, because of the possibility of increased toxicity the manufacturer recommends caution with antineoplastics principally metabolised by the cytochrome P450 isoenzyme CYP3A4, particularly irinotecan, and also etoposide, vinorelbine, paclitaxel, ifosfamide, imatinib, vinblastine and vincristine, although there appears to be some limited evidence of safe concurrent use. 

The rate of auto-induction of cyclophosphamide was 23% lower and exposure to the active metabolite 4-hydroxycyelophosphamide was 5% lower in 6 patients receiving aprepitant with a 4-day course of high-dose CTC (cyclophosphamide, thiotepa, carboplatin) when compared with 49 patients receiving high-dose CTC without aprepitant. ... 

In the short-term, aprepitant is an inhibitor of the cytochrome P450 isoenzyme CYP3A4, and might therefore reduce the activation of antineoplastics activated by this isoenzyme (cyclophosphamide, thiotepa), or increase the toxicity of antineoplastics metabolised by this enzyme (docetaxel, irinotecan). 

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