Gastrointestinal drugs (Jan 2019–Dec 2019)

Serotonin Syndrome Triggered by an Interaction Between Opioid Analgesics and Cobicistat: A Challenging Diagnostic Case Report

“…Combination medication regimens, including cobicistat, may be associated with an increased risk for serotonin syndrome given many serotonergic agents are metabolized by CYP2D6 and CYP3A4 (Table 2) [11]. Similar interactions have been noted in previous literature, including a 2012 case report where a patient on HIV medication darunavir/ritonavir, proton pump inhibitor esomeprazole, and SSRI escitalopram developed a similar case of SS [12], and a 2019 case involving a patient on an antiretroviral therapy of elvitegravir, cobicistat, emtricitabine, and tenofovir disoproxil fumarate who was started on escitalopram for anxiety, with concomitant receipt of ondansetron for nausea, who developed serotonin syndrome [13]. While it is well known that CYP inhibitors have the potential to cause SS, patients taking HIV combination antivirals with CYP2D6 and CYP3A4 inhibitors may be at higher risk of being underdiagnosed given the abundant drug interactions involved in HIV treatment regiments.…”