Study Set Content:
For example, the withdrawal of (blank)( a drug whose ⍺ 2-
adrenoreceptor agonist activity reduces blood pressure) can
produce hypertensive crisis, probably because the drug down-
regulates ⍺ 2 adrenoceptors.
clonidine
Before initiating therapy with a drug, be aware of patient
characteristics that may limit the clinical response.
Changes in Components of Response Distal to the
Receptor
These Characteristics include:
o The (blank) of the patient
age and general health
The (blank) of the
disease. The most important potential cause of failure to
achieve a satisfactory response is that the diagnosis is
wrong or physiologically incomplete.
severity and the pathophysiologic mechanism
BENEFICIAL VERSUS TOXIC
EFFECTS OF DRUG
Clinical selectivity
No drug causes only a single, specific effect
Why is this so?
o It is exceedingly unlikely that any drug molecule will bind to
only a single type of receptor molecule, if only because the
number of potential receptors in every patient is
astronomically
large
Drugs are only selective rather than (blank) in their
actions.
specific
Drugs are only selective rather than specific in their
actions.
o Because... they bind to (blank)
more tightly than to others and because these receptors
control discrete processes that result in distinct effects.
one or a few types of receptors
SELECTIVITY IS USUALLY CONSIDERED BY SEPARATING
EFFECTS INTO TWO CATEGORIES:
Beneficial or therapeutic effects
Toxic or adverse effects
Pharmaceutical advertisement and prescribers occasionally use term
(blank), implying that the effect in question is insignificant or
occurs via a pathway that is to one side of the principal action of
the drug:
side effects
Pharmaceutical advertisement and prescribers occasionally use term
side effects, implying that the effect in question is insignificant or
occurs via a pathway that is to one side of the principal action of
the drug: such implications are frequently
erroneous
Beneficial and Toxic Effects Mediated by the Same
Receptor-Effector Mechanism
Serious drug toxicity in clinical practice represents a direct
pharmacologic extension of the(blank) of the drug.In some of these cases:(eg. bleeding caused by anticoagulant
therapy; hypoglycemic coma due to insulin)
therapeutic actions
Toxicity may be avoided by: Management of the (blank) of drug administered, guided
careful monitoring of effect measurements of blood
coagulation or serum glucose
dose
Aided by (blank)measures
ancillary measures
ancillary measures
(avoiding tissue trauma that
may lead to hemorrhage; regulation of carbohydrate intake).
In still other cases, the toxicity may be avoided by not
(blank)at all, if the therapeutic indication is
weak or if another therapy is available.
administering the drug
Many drugs produce both their desired effects and adverse effects
by acting on a (blank) receptor type in different tissues.
single
which act by inhibiting Na +K + -
ATPase in cell membranes.
Digitals Glycosides
which inhibits the enzyme dihydrofolate
reductase and,
Methotrexate
THREE THERAPEUTIC STRATEGIES:
The drug should always be administered at the(blank)
that produces acceptable benefits.
lowest dose
