Drug-independent Effects I

Placebo
A placebo is a dosage form devoid of an
active ingredient, a dummy medication.
Administration of a placebo may elicit
the desired effect (relief of symptoms)
or undesired effects that reflect a
change in the patient’s psychological
situation brought about by the therapeutic
setting.
Physicians may consciously or unconsciously
communicate to the patient
whether or not they are concerned
about the patient’s problem, or certain
about the diagnosis and about the value
of prescribed therapeutic measures. In
the care of a physician who projects
personal warmth, competence, and confidence,
the patient in turn feels comfortable
and less anxious and optimistically
anticipates recovery.
The physical condition determines
the psychic disposition and vice versa.
Consider gravely wounded combatants
in war, oblivious to their injuries while
fighting to survive, only to experience
severe pain in the safety of the field hospital,
or the patient with a peptic ulcer
caused by emotional stress.
Clinical trials. In the individual
case, it may be impossible to decide
whether therapeutic success is attributable
to the drug or to the therapeutic
situation. What is therefore required is a
comparison of the effects of a drug and
of a placebo in matched groups of patients
by means of statistical procedures,
i.e., a placebo-controlled trial. A
prospective trial is planned in advance, a
retrospective (case-control) study follows
patients backwards in time. Patients
are randomly allotted to two
groups, namely, the placebo and the active
or test drug group. In a double-blind
trial, neither the patients nor the treating
physicians know which patient is
given drug and which placebo. Finally, a
switch from drug to placebo and vice
versa can be made in a successive phase
of treatment, the cross-over trial. In this
fashion, drug vs. placebo comparisons
can be made not only between two patient
groups, but also within either
group itself.