Deregulated kynurenine metabolism - An alternate hypothesis for COVID-19 associated anosmia

Unbalanced IDO1/IDO2 Endothelial Expression and Skewed Keynurenine Pathway in the Pathogenesis of COVID-19 and Post-COVID-19 Pneumonia

Despite intense investigation, the pathogenesis of COVID-19 and the newly defined long COVID-19 syndrome are not fully understood. Increasing evidence has been provided of metabolic alterations characterizing this group of disorders, with particular relevance of an activated tryptophan/kynurenine pathway as described in this review. Recent histological studies have documented that, in COVID-19 patients, indoleamine 2,3-dioxygenase (IDO) enzymes are differentially expressed in the pulmonary blood vessels, i.e., IDO1 prevails in early/mild pneumonia and in lung tissues from patients suffering from long COVID-19, whereas IDO2 is predominant in severe/fatal cases. We hypothesize that IDO1 is necessary for a correct control of the vascular tone of pulmonary vessels, and its deficiency in COVID-19 might be related to the syndrome’s evolution toward vascular dysfunction. The complexity of this scenario is discussed in light of possible therapeutic manipulations of the tryptophan/kynurenine pathway in COVID-19 and post-acute COVID-19 syndromes.

Drug interaction risk between cardioprotective drugs and drugs used in treatment of COVID-19: A evidence-based review from six databases

BACKGROUND AND AIMS

This Review discusses the potential drug interactions risk between Drugs used in treating COVID-19 infection and Drugs used in treating comorbid conditions (Diabetes, hypertension, cardiovascular illness).

METHOD

Six Databases were consulted a) Micromedex drug interaction b) Medicine complete.com c) Liverpool Drug Interaction Group for COVID-19 therapies d) Epocrates e) Medscape f) drugs.com. To acquire information on possible interaction effects between drugs used for COVID-19 treatment such as atazanavir, lopinavir/ritonavir, remdesivir, molnupiravir, paxlovid(nirmatrelvir/ritonavir), dexamethasone, azithromycin, chloroquine, and FDA approved monoclonal antibodies with primarily used antidiabetic drugs, antihypertensive drugs, and drugs acting on the cardiovascular system.

RESULTS

Potential interaction effects such as worsening glycemic control were prominent with lopinavir/ritonavir and the primarily used antidiabetic drugs, which needs dosage adjustment and close monitoring. The risk of hypotension and irregular heart rhythm is the potential interaction effects with concomitant use of drugs for COVID-19 treatment and antihypertensive drugs. Caution is advised with drugs such as atazanavir and lopinavir/ritonavir when concomitantly used in treating comorbid conditions. Drugs such as remdesivir, molnupiravir, and some monoclonal antibodies are safer in use with drugs used in treating the comorbid condition.

CONCLUSIONS

Drug-drug interaction remains one of the significant factors in altering the therapeutic efficacy. Drugs used to manage comorbid conditions may influence the COVID-19 treatment with potential interaction effects. These enhance the view on safety concerns about the drug interaction risk in managing COVID-19 infection in patients with comorbid conditions. This primary evidence may concern preventing potential or unintentional effects resulting from Drug-drug interaction, Improving patient quality of life.