Date of report 28 Jul 2020

Reported case interaction between
Ritonavir and Paclitaxel

This is about an HIV-infected patient successfully treated with ABC/3TC/DRV/r who was diagnosed with metastatic gastric cancer for which palliative treatment with paclitaxel/carboplatin was indicated. The HIV physician and oncologist were aware of a potential interaction between DRV/r and paclitaxel (see Liverpool site) but a switch to an integrase inhibitor was not chosen due to concern about a psychiatric history in this patient. Rilpivirine was considered but not attractive due to expected use of PPIs around the chemotherapy cycles. As the Liverpool site recommended close monitonring of toxicity and uncertainty whether paclitaxel levels would go up or down, the DRV/r regimen was continued and the patient was monitored according to usual toxicity evaluation by the oncologist. The 1st cycle of chemotherapy was administered in normal dose and no toxicity occurred. The 2nd cycle was also given in normal dose. Three days later the patient became ill, got fever, mucositis, positive blood culture for E coli, and two days later died. Obduction showed extensive mucositis, no perforation.