Safety pharmacology seeks to predict if a drug administered to humans would be unsafe. Prior to 1990, companies conducted toxicological testing during drug discovery. In the 1990s, the antihistamine terfenadine was withdrawn due to its potential for life-threatening cardiac side effects. This led to increased efforts by industry and regulators through initiatives like the International Conference on Harmonisation to improve safety testing and accommodate regulatory requirements. Safety pharmacology testing helps determine potential undesirable effects on body systems and inform decisions on advancing to human testing or discontinuing development, with the goal of identifying unsafe drugs early.

2. It is the discipline that seeks to predict
whether a drug, if administered to human
populations, is likely to be found unsafe,
and its professional mendate is to prevent
such an occurrence.

3. • Prior to 1990, prarmaceutical
companies conducted toxicological
testing of lead compounds as part of
preclinical drug discovery.
• In the mid 1990s, the antihistamine,
terfenadine, was withdrawn
following a growing awareness that
the drug could evoke the potentially
life threatening cardiac syndrome,
torsades de pointes.

4. So, how has this impacted on the
unfolding history of safety
pharmacology?
 In the absence of quantification of the
predictive value of tests and
programmes, industry and the
regulators have attempted to
accommodate one another through a
series of industry and regulatory led
initiatives.
 Of the latter, the most imp is ICH.

5. The ICH is a project started in
1990that utilises the regulatory
authorities of the united states,
Europe and Japan in conjuction with
experts from the pharmaceutical
industry to discuss scientific and
technical aspects of therapeutic drug
registration.

6. What has this to do with
pharmacology?
The answer is that Safety Pharmacology
has been shaped in structure and
function by this ongoing
accommodation between
pharmacologists and regulatory
authorities.

7.  To determine the potential undesirable
pharmacodynamic effects of a drug on CVS,
CNS and respiratory systems, as well as to
implement supplementary tests to evaluate other
organ systems.
 To take account of regulatory requirements.

8.  To determine whether a drug is effective
 To help inform the decision to begin testing
in humans.
 To determine if a drug is ‘unsafe’ and if this
is not the case, to inform drug discovery that
the drug is likely to be ‘safe’

10.  To provide companies with data to
discontinue development of unsafe drugs
early in the preclinical development phase.
 To identify a drug as potentially safe.
 To minimize testing time
 To identify quickly and accurately any ‘show
stopper’ adverse effect liability as soon as
possible.

11.  If drug development can be terminated
during the preclinical testing phase instead
of phase 3, there is a major resource and
financial advantage.

12.  At the end of the discovery process, just prior to
phase1 clinical investigations, there will be
detailed portfolio of of safety pharmacology data
for the nominated compound including GLP
studies
 For any NCE that fails it is the goal of safety
assessment to inform the decision as early and
possible in the discovery process for reasons of
cost and time.

13. 1. Preclinical safety pharmacology models require
better validation
2. Validation requires a quantitative and accurate
human template of liabilities of positive and
negative controls with which to compare model
data sets
3. Validation is not possible for models screening
for liabilities that are rare or imprecise with
current drug in humans

14. 4. Validation is not possible for methods for
evaluating human specific biologics.
5. In the absence of validation it is better to
live with false positives than risk the chance of
false negatives.