1.
PLACEBO
BY Dr . RAVINDRA KUMAR.G

2.
1.Definition, Effects, Ethics
2.History
3.Mechanism of the effect
4.Clinical utility
5.The individual variation
6.Symptoms and conditions
7.In research

3.
1.DEFINITION, EFFECTS, ETHICS-
 Placebo means “I will please”(Latin)
 A substance or procedure that is objectively without
specific activity for the condition being used.
 Ex- inert tablets, vehicle infusions, sham surgery
, sham acupuncture, sham electrodes, ultra sound.
 Inert tablets made up of starch or lactose

4.
 PLACEBO EFFECT-it is a therapeutic effect in the
patient who had received placebo (but not told
that it is inert substance)
 Placebos may also have positive effect on
patient’s, who knows that it is inert substance

5.
 Placebo reactors-those who responds to the
placebo positively
 Neurotics are great placebo reactors
 While depressed are resistant

6.
 The physician has even been called a placebo
 Placebo effect has sometimes been defined as
physiological effect, but it is illogical, as placebo does
not directly cause anything
 Some studies also indicated that animals(dogs) also
have relieved symptoms

7.
2.HISTORY-
 John haygarth was the first to investigate efficacy of
placebo
 Richard cobat said “I have not yet found any case in
which a lie does not do more harm than good”
 T.C.graves first defined the placebo effect

8.
3.MECHANISM OF THE EFFECT-
 Placebo effect is highly variable in it’s magnitude
 placebo interventions can alter hormone levels or
endogenous opioids(endorphins)
a)Expectancy and conditioning-
 Placebo effect is related to the perceptions
, expectations of the patient
 The expectancy can be enhanced through factors such
as the enthusiasm of the doctor, differences in size and
color of placebo pills

9.
 Placebos can act similarly through classical
conditioning
 In a trial of anti-depressants, "Once the trial was over
and the patients who had been given placebos were
told as much, they quickly deteriorated“
 The perceived consumption of caffeine has been
reported to cause similar effects even when
decaffeinated coffee is consumed

10.
 Perceived ergogenic aids can increase
endurance, speed and weight-lifting ability
 Proper adherence to placebos is associated with
decreased mortality
 Placebo treatment varies widely with society
 The placebo effect can work selectively

11.
b) placebo effect and the brain-
 Functional imaging upon placebo analgesia shows
activation of some areas in brain
 Different areas in the brain have different functions
 High placebo responses link with dopamine activity
 Nonanalgesic placebo effects:
Parkinson's disease-with the release of dopamine

12.
C)Brain and body;
 Research upon conditioning in animals shows the
brain can learn control over them
 placebo effects can extend beyond the brain.

13.
4.CLINICAL UTILITY-
a)Duration;
 Placebo effects can last for a long time
over 8 weeks for panic disorder,
6 months for angina pectoris,
two and half years for rheumatoid arthritis.

14.
b)Clinical significance;
 The placebo effect does not have "powerful
clinical effects" (objective effects) and that
patient-reported improvements
(subjective effects) were small and could not be
clearly distinguished from reporting bias

15.
 Another researchers noted different conclusions
that placebo effects are indeed significant but
small in magnitude
 Placebos used as therapeutic agent that work
psychologically
 To sort out real drug related ADR

16.
c)Negative effects
 inert substances have the potential to cause
negative effects
 Latin nocebo = I will harm
 a patient who disbelieves in a treatment may
experience a worsening of symptoms
 negative consequence is that placebos can
cause side-effects associated with real treatment
 Withdrawal symptoms can also occur after
placebo treatment

17.
d)Doctor-patient relationship
 The most frequently prescribed placebos
were antibiotics for viral infections, and vitamins
for fatigue
 The following impracticalities exist with placebos
1.Roughly only 30% of the population seems
susceptible to placebo effects
2.Patients rightfully want immediate relief
3.doctors and pharmacists could open themselves
up to charges of fraud

18.
 Critics of the practice responded that it is
unethical to prescribe treatments that do not
work
 placebos as a diagnostic tool
 The placebo administration may prove to be a
useful treatment in some specific cases where
recommended drugs cannot be used.

19.
 The House of Commons of the United
Kingdom Science and Technology Committee has
stated
- homeopathy is a placebo treatment
- Government should have a policy on prescribing
placebos.
 Beyond ethical issues prescribing pure placebo is
bad medicine

20.
5. THE INDIVIDUAL VARIATION-
 Though not everyone responds to a
placebo, neither does everyone respond to an
active drug
 Children seem to have greater response
than adults to placebos

21.
 6.SYMPTOMS AND CONDITIONS-
 symptoms such as pain, swelling, stomach
ulcers, depression, and anxiety
 Some list of medical conditions
-Asthma
-Bipolar mania
-Cough
-Nausea
-Depression
-HTN
-migraine

22.
7.IN RESEARCH-
 Placebos are used during clinical trails
 If a person is given a placebo under one
name, and they respond, they will respond in the
same way on a later occasion.
 In double blinded studies the placebo effect is
weaker

23.
THANK U