Date of report 31 Jan 2020
Reported case interaction between
Cobicistat and Duloxetine
Cobicistat and Duloxetine
Drugs suspected to be involved in the DDI-summary
Complete list of drugs taken by the patient
duloxetine 120 mg qd lormetazepam 2mg qd omeprazol 20mg qd gabapentin 200mg qd paracetamol on demand
Clinical case description
59-year-old HIV positive patient, known for HIV infection on ART. Undetectable on DRV/c as monotherapy (the patients doesn’t want to modify regimen). Depressive syndrome was diagnosed by his primary physician, starting duloxetine 60mg/d, soon increased to 120mg/d in June 2019. Duloxetine is metabolized by CYP2D6 and CYP1A2, thus Darunavir/cobicistat could potentially slightly increase duloxetine concentration as cobicistat is a weak inhibitor of CYP2D6. However, despite being receiving the highest recommended dose (120 mg daily), no adverse events were observed.
Clinical Outcome
Editorial Comment
This is a nice case showing that what may be defined as a "potential weak interaction" can be managed in a tailored way. A PLWH already on cobicistat boosted darunavir started duloxetine at 60 mg; after reporting no side effects the dose was increased to 120 mg and, after a follow up of almost 8 months, no side effect emerged. In cases of weak interaction with drugs lacking a narrow therapeutic index titration of the victim drug is a potential option when alternative are lacking.
University of Liverpool Recommendation
Potential interaction likely to be of weak intensity. Additional action/monitoring or dosage adjustment is unlikely to be required