| Ciprobay:
Proof of efficacy
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Nutrient solutions for
a wide range of experiments with bacteria
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More than 200 million people in 80 countries have been treated
with Bayer’s Ciprobay so far. This drug is a highly
effective antibiotic which has now been authorized even in
children and adolescents for the treatment of particularly
severe exacerbations of infection in cystic fibrosis.
Doctors use this drug mainly to treat respiratory and urinary
tract infections. It is also used to treat bacterial soft
tissue infections and sepsis (“blood poisoning”).
This antibiotic became famous after terrorist attacks in the
USA, when anonymous letters were posted which contained highly
dangerous anthrax bacteria. The victims were treated with
Ciprobay, and the US government also ordered large quantities
of the drug to enable them to respond quickly and effectively
to more large-scale attacks.
There are now 9,000 studies and more than 32,000 publications
documenting the excellent efficacy and safety of this product.
Many animal studies had to be conducted in the development
of Ciprobay, of course.
What did the animal study used to show
efficacy involve?
In this type of study, the researchers work with mice. In
order to test the antibiotic, bacteria which have caused infections
in patients are injected into the abdominal cavity of the
animals. Within a short time, the bacteria spread through
the whole body and cause sepsis.
During the study, five mice remain untreated (this is known
as the “control group”), while four other groups
of five mice receive different doses of the actual drug. Just
this small number of animals is sufficient to produce statistically
meaningful data. The study serves to determine the dose at
which the drug is effective.
The data from studies with various strains of bacteria which
cause diseases in different organs are compiled in a document
called the “Investigator’s Brochure”, which
in turn (in addition to the results of other studies) serves
as a basis for the clinical
studies. Without these data, the next step in the drug
development process, in which the active ingredient is administered
to humans for the first time, could not take place.
What happens to the mice after the
study?
The mice in the control group usually succumb to infection
after approximately 24 hours because they have been infected
with a high dose of organisms for the purpose of the study.
The course of the disease in the animals given the active
ingredient under investigation is monitored closely. In the
groups in which animals survive the infection, Ciprobay shows
efficacy - unlike in the control group.
The mice in the treated group have to be put down after the
end of the study. They can no longer be used for other studies
because they have already been treated. Statistically meaningful
results could not therefore be obtained in new studies.
In other studies (e.g. toxicology studies), in which the
animals are treated only with the active ingredient, the scientists
examine the animals’ organs very closely in order to
identify possible side effects. Only when it has been proven
beyond doubt that the active ingredient is safe in animal
studies can clinical testing begin.
Can’t the effects be researched
in the test tube too?
It is widely believed that the effects of such substances
can also be researched in the test tube. Unfortunately, however,
that is not the case. The reason for this is that the way
in which infection responds in the body cannot be reproduced
in a test tube. Only with animal studies is it possible to
determine whether the active ingredient even actually reaches
an infected organ, for example. And it needs to do this if
it is to have any effect on the organ at all and later cure
innumerable people.
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