- Many drugs were tested to use as a potential Covid-19 treatment.
- Dexamethasone is only known to be effective for severe cases of the disease.
- Now, researchers are investigating Prozac as this may suppress the replication of SARS-Cov-2.
On 16 June 2020, an ongoing clinical trial for a potential Covid-19 treatment finally brought good news. Dexamethasone, a common corticosteroid, could result in saving many lives among the most severely affected Covid-19 patients.
But the search for other treatment options is still ongoing, and one unlikely drug is being investigated – Prozac.
An antidepressant for a viral disease?
The name “Prozac” is not unfamiliar. This antidepressant medication, also known by its generic name fluoxetine, is a selective serotonin uptake inhibitor (SSRI) which first appeared on the market in the late 1980s.
It is often used as a treatment for depression, anxiety and obsessive-compulsive disorder. Now, researchers from the Julius-Maximilians-Universität Würzburg are investigating this medication as an effective treatment for the early stages of Covid-19.
The team found that the SSRI could significantly halt the early replication of the SARS-CoV-2, which means that the virus has a smaller chance of gaining a foothold in the body, causing severe illness.
The study, which has not yet been peer-reviewed, is available in full on bioRxiv.
What does the research say?
The researchers tested different types of SSRIs, which included fluoxetine, escitalopram and paroxetine to see how they would fare in reducing the replication of SARS-CoV-2.
They incubated cells with the agents while increasing the concentration of the drugs in the cells. These cells were all infected with SARS-CoV-2 and the viral replication was extracted and tested with the real-time polymerase chain reaction (RT-PCR) method.
The viral level was significantly decreased in these cells, which means that fluoxetine was effective at suppressing the virus. However, the researchers believe that the effect had nothing to do with the inhibition of serotonin, since the paroxetine and the escitalopram didn’t have the same effect.
Instead, they believe that it had to do with the way two optical isomers in fluoxetine inhibited the virus.
Did the fluoxetine have the same effect on other viral infections?
According to the research team, they also tested this effect of fluoxetine on other viruses such as rabies, human respiratory syncytial virus or the herpes simplex virus, but it didn’t have the same effect.
They therefore believe that the effect of fluoxetine is specific to the SARS-CoV-2 virus.
Would a lengthy clinical trial be necessary?
As we have seen since the start of the outbreak, some scientific teams are circumventing time-consuming, lengthy clinical trials to fast-track the testing of medications that are already available.
Several medications are currently used “off-label” in the fight against Covid-19 and a comprehensive review has been published to document these medications and to encourage further investigation.
Why is this discovery good?
Right now, the press release on the breakthrough in the dexamethasone trial stated that this medication was used in patients who were already badly affected by Covid-19. These patients were already hospitalised and on a ventilator.
Dexamethasone could help save lives as it suppresses the immune system and treats inflammation. One of the significant causes of severe illness and death among Covid-19 patients has been an overreaction of the immune system. Therefore, this method would not be suited for treatment early on in the disease, as one does not want to suppress the immune system at that stage.
However, if Prozac could suppress the viral replication of SARS-CoV-2, it could help sidestep the most severe stage of Covid-19.
It is, however, important to note that the research is still in its early stages and that the study has not yet been peer-reviewed.
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