A pill which has been used to treat toenail infections for decades could help treat Covid by blocking production of the virus, a new study has suggested.

The antifungal drug itraconazole - also known as Snoporax - was said to have killed the bug in experiments.

Anti-depressant fluoxetine, or Prozac, had the same effect, but worked best together with coronavirus treatment remdesivir, scientists said.

Mixing the drugs offered hopes of a 'Covid cocktail', say the German and Finnish team behind the research, who now want to start human trials.

Both treatments blocked SARS-CoV-2 - the virus that causes the infection - in cells grown in the lab, the study found.

The combined therapy blocked production by more than 90 per cent, reports the British Journal of Pharmacology.

Antifungal drug itraconazole

Senior author Professor Ursula Rescher, of the University of Muenster, said: "Preventive vaccination and therapeutic medicines against Covid-19 are both required to effectively combat pandemics caused by emerging zoonotic viruses such as SARS-CoV-2."

Snoporax and Prozac have been commonly prescribed across the world for around 30 years.

Combining either with remdesivir are "promising starting points" for therapeutic options to control SARS-CoV-2 infection and severe progression of Covid, she said.

Using more than one drug can target different molecular pathways - a key strategy to achieving therapeutic success with lower doses.

It also reduces the likelihood of the development of drug resistance, she added.

But thorough safety tests will be essential before they can be tried on patients, warned the researchers.

The antidepressant drug Prozac, also known as fluoxetine (
Image:
REUTERS)

Prof Rescher explained: "The translation of lab results into the clinics remains a major challenge.

"Combined medications bear the risk of drug-drug interactions which may lead to reduced therapeutic benefit or even severe adverse effects.

"Therefore, it is important to mention that a vast number of drugs are currently known to interact with itraconazole, fluoxetine and even remdesivir.

"Furthermore, the patient's genetic disposition and physiological or pathophysiological conditions demand for a careful evaluation of the appropriate treatment strategy.

"Thus, it is paramount to evaluate the patient-related risks and benefits, as co-administration of drugs might be contra-indicated in certain patients."

But she added the analysis showed 'promising novel options' for treating coronavirus.