British Heart Foundation: Scientists at the University of Oxford, part
funded by us, are using a drug developed in 1950 for the treatment of
Lupus to lower an abnormally high heart rate in those with heart failure
and high blood pressure. Hydroxychloroquine (HCQ) was created to combat malaria, and was later
found to be useful in the treatment of Lupus and rheumatoid arthritis.
Now, a team at the University of Oxford has found that the drug can also
reduce heart rate. Published today in the journal Heart Rhythm, the treatment has the potential to benefit people with heart failure, high blood pressure, angina and other heart conditions.
Dr Rebecca Burton, who led the research and is funded by us, said:
“The starting point was a chance observation. A patient being treated
for Lupus also had a high heart rate. When the patient started
Hydroxychloroquine for the Lupus, their heart rate reduced. We started
to think about how the drug might be acting in the heart and began
extensive pre-clinical studies."
The researchers found that the drug acts on an area of the heart
called the sino-atrial node. This group of cells keeps the heart beating
by producing a rhythmic electrical signal that is transmitted to the
rest of the heart muscle. The drug targets a particular protein in this
region of the heart to restrict an electrical signal known as the ‘funny
current’ that is especially important in setting the heart rate.
The effects of HCQ on the heart were studied in the late 1950s but
initial findings were not followed up. There were also reports of
lowered heart rate as a side-effect in patients treated for other
conditions, but the potential of this drug as a heart treatment had not
been pursued fully until the Oxford team began their research.
Dr Burton said: "The number of drugs on the market and the number of
possible conditions are so huge that it takes a lucky observation to
connect something which might be viewed as an annoying side-effect to
something which could have a clinical benefit.”
HCQ has a well-established safety profile. Side-effects are limited
and well understood, and it is possible to use it for children and
pregnant women under specialist care.
Professor Jeremy Pearson, our Associate Medical Director, said: “This
study is an elegant example of how a chance clinical observation,
carefully followed up, can provide evidence in favour of an unexpected
new use for an old drug. However, a clinical trial is needed to
establish whether HCQ is as safe and effective as existing medicines
used to reduce heart rate.”