DULOXETINE

What is duloxetine (Cymbalta, Yentreve)?

Most used for anxiety and depression, duloxetine belongs to a class of medication called serotonin-norepinephrine reuptake inhibitors (SNRIs). Serotonin is a molecule in the body that aids in mood, sexual desire, sleep, digestion, wound healing, bone health, and blood clotting [1]. It is often referred to in psychology as the “happy” chemical. Norepinephrine is thought to play a role in the body’s stress response and helps to regulate sleep, alertness, and blood pressure [2]. In conditions like depression and anxiety, the brain is dealing with an imbalance of chemicals such as serotonin and norepinephrine. SNRIs, like duloxetine, work by keeping serotonin and norepinephrine in the space where they can readily be available for bodily processes. 

How can duloxetine help with long-COVID?

Many people diagnosed with long-COVID suffer from “brain fog,” which includes decreased cognitive acuity, memory deficits, poor focus, reduced ability to multitask, and reduced concentration [2]. The proposed reason for this is that during a COVID-19 infection, the body’s immune response becomes activated, causing heavy amounts of inflammation. This inflammation affects the central nervous system (CNS), the brain, and the spinal cord.

Serotonin and norepinephrine have been shown to have an effect against this viral inflammation by blocking certain viruses (like HIV-1) into the cells. In addition, they can decrease cytokine production, promoting the immune response [3]. Since serotonin and norepinephrine possess anti-inflammatory properties and may inhibit viral activity, duloxetine could be an option for treating long-COVID. Duloxetine keeps these chemicals around longer in the body so they can perform their functions. Therefore, the longer they are active, the more immune response, and symptoms of depression have a higher chance of decreasing.

Aside from depression, duloxetine can also be used to treat peripheral neuropathy (numbness/tingling in the extremities). Some patients with long-COVID experience neuropathy as a side effect, and duloxetine has shown effectiveness as a treatment. In a webinar sponsored by the Centers for Disease Control (CDC), duloxetine was listed as an option for small fiber neuropathy caused by long-COVID [4].

Further research needs to be conducted in clinical trials to assess the effectiveness of duloxetine for treating long-COVID; however, for symptom management of depression and neuropathy, duloxetine may be an option for patients. As its effects are multifold, duloxetine may hold more value over other SNRIs and help to decrease pill burden while also assisting patients in returning to their pre-COVID baselines.

References

¹https://my.clevelandclinic.org/health/articles/22572-serotonin

²https://americanaddictioncenters.org/antidepressants-guide/ndris

³https://www.medtextpublications.com/open-access/long-covid-is-there-a-role-for-antidepressants-1249.pdf

⁴https://emergency.cdc.gov/coca/ppt/2021/012821_slide.pdf