Should we be concerned when COVID-19-positive patients take opioids to control their pain? Insights from a pharmacological point of view.

The purpose of this narrative review is to discuss the available information regarding the currently utilized COVID-19 therapies (and the evidence level supporting them) and opioids for chronic pain with a focus on warnings of potential interactions between these two therapeutic approaches. Papers were retrieved from a PubMed search, using different combinations of keywords [e.g., pain treatment AND COVID-19 AND drug-drug interaction (DDI)], without limitations in terms of publication date and language. Remdesivir is an inhibitor of CYP3A4 and may increase the plasma concentration of CYP3A4 substrates (e.g., fentanyl). Dexamethasone is an inducer of CYP3A4 and glycoprotein P, thus coadministration with drugs metabolized by this isoform will lead to their increased clearance. Dexamethasone may cause hypokalemia, thus potentiating the risk of ventricular arrhythmias if it is given with opioids able to prolong the QT interval, such as oxycodone and methadone. Finally, the existing differences among opioids with regard to their impact on immune responses should also be taken into account with only tapentadol and hydromorphone appearing neutral on both cytokine production and immune parameters. Clinicians should keep in mind the frequent DDIs with drugs extensively metabolized by the CYP450 system and prefer opioids undergoing a limited hepatic metabolism. Identification and management of DDIs and dissemination of the related knowledge should be a major goal in the delivery of chronic care to ensure optimized patient outcomes and facilitate updating recommendations for COVID-19 therapy in frail populations, namely comorbid, poly-medicated patients or individuals suffering from substance use disorder.