Niclosamide, a drug that is used for tapeworm
infections and emricasan, which is being tested for certain liver diseases, may
be the answer to the Zika virus
- Infection with the mosquito-borne Zika virus during pregnancy
can cause the baby to be born with a small head (microcephaly)
- A research team from Florida State University, the Johns
Hopkins University and the National Institutes of Health investigated
compounds that are already in use, in clinical trials or pharmacologically
active to find a drug that is effective against the Zika virus.
- One possible candidate is niclosamide, a drug that is used in
the treatment of tapeworm infection and is safe in pregnancy. Another is
emricasan, which is being investigated in certain liver diseases.
. Researchers from the Florida State University, the Johns Hopkins
University and the National Institutes of Health concluded the same; the
findings of their research were published in Nature Medicine
The Zika virus
had recently threatened to disrupt the
Olympic Games in Rio, Brazil. Several
babies whose mothers were infected with the virus during pregnancy were born
with small heads and brains, a condition referred to as microcephaly
. The urgency to find a cure
for the condition prompted researchers to test several compounds for their
effectiveness against the Zika virus.
‘Anthelminitic drug niclosamide and casapase inhibitor emricasan may be effective in the treatment of Zika.’
They tested compounds that are
currently available for clinical use for some other disease, in clinical trials
or which are pharmacologically active. Such compounds are likely to take less
time for their development into an effective treatment for Zika infection.
The researchers tested around 6000
compounds. They identified compounds that stopped the Zika virus from
multiplying and others that stopped the virus from killing fetal brain cells.
One of the compounds that prevented the virus from multiplying was
niclosamide. Niclosamide is an anthelmintic drug hat is approved for the
treatment of tapeworm infection
. It belongs to the FDA pregnancy Category B, and is considered
relatively safe for use in pregnancy. This plus point could enable its use in
pregnant women with the Zika virus, the population that needs the medication
However, there still remain
several hurdles to cross before the drug can be used to treat Zika infection.
It is not known if the drug can produce the same effect in the human body
against the virus as it produced in the laboratory.
Niclosamide is not much absorbed
from the digestive tract into the blood, therefore, it remains to be seen how
the medication will reach the virus in the rest of the body. The exact dosage
and treatment regimen for Zika has still to be established. Niclosamide is
currently not available in the United States.
Another compound, emricasan, a caspase inhibitor was found to prevent
death of immature brain cells caused by the Zika virus in the laboratory and
therefore has the potential to protect against microcephaly
. Emricasan is currently in
clinical trials for the treatment of certain liver problems. Nine other
compounds prevented the replication of the virus. Using a combination of
antiviral and brain-protective compounds provided additional protection to the
The Zika virus is spread through
the bite of an infected Aedes aegypti
mosquito, through sexual transmission and from the mother to the baby.
Currently, the only way to prevent the infection is to keep mosquitoes at bay.
Treatment for the infection is not available; most people respond to
- Xu M et al. Identification of small-molecule inhibitors of Zika virus infection and induced neural cell death via a drug repurposing screen. Nature Medicine (2016) doi:10.1038/nm.4184
- NIH Collaboration Helps Advance Potential Zika Treatments - (https://www.nih.gov/news-events/news-releases/nih-collaboration-helps-advance-potential-zika-treatments)