NSG 251 Practice Questions 2025 Latest and
Verified Answers
How do drugs exert actions?
Receptors, enzymes and nonselective physiology
Receptors
Reactive site on surface or inside cell (molecular structure of drug is critical)
What two ways do drugs interact with receptors
Elicit or block physiologic response
Affinity:
Degree which a drug attaches to and binds with a receptor; drug with the best "fit" and
strongest affinity will elicit the greatest response
Enzymes
Drugs bind to enzyme and either inhibit (more common) or enhance (less common) the action
of a specific enzyme // this process is called selective interaction
Nonselective interactions
Nonspecific mechanism of action ; Drugs do not interact with receptors or enzymes --> Their
main targets are cell membranes and various cellular processes such as metabolic activities ;
These drugs can either physically interfere with or chemically alter cellular structures of
processes ; Some cancer and antibiotic do this
Agonist
,Drug binds to the receptor; there IS a response
Partial agonist (agonist-antagonist)
Drug binds to the receptor; the response is diminished compared with the elicited by an agonist
Antagonist
Drug binds to the receptor; there is NO response. Drug prevents binding of agonists
Competitive antagonist
Drug competes with the agonist for binding to the receptor. If it binds, there is NO response
Noncompetitive antagonist
Drug combines with different parts of the receptor and inactivates it; agonist then has no effect
Pharmacotherapeutics
The clinical use of drugs to prevent and treat diseases
Acute therapy
Intensive drug treatment for acutely ill, needed to sustain life
Maintenance therapy
Prevents progression of a disease, treats chronic illnesses
Supplemental (replacement) therapy
Supplies body with substance needed to maintain normal function. I.e. - Insulin for
diabetic, iron for anemia
Palliative therapy
Make Pt comfortable, provide relief from pain, stress of serious illness. I.e. - opioids for end of
life
Supportive therapy
, Maintain integrity of body functions while Pt recovers from illness/trauma. I.e. - electrolytes to
prevent dehydration due to vomit/diarrhea
Prophylactic therapy
Prevent illness. I.e. - preoperative antibiotic. Vaccine to traveler
Empiric therapy
Based on clinical probabilities, when a certain pathologic condition has high likelihood of
occurrence based on the patient's initial presenting symptoms. Ex] Use of antibiotics active
against the organism most commonly associated with specific infection before the results of the
culture and sensitivity reports are available
Monitoring:
Therapy implemented, effectiveness must be evaluated. I.e. - Giving antihypertensives
and monitoring blood pressure
Adverse drug event (ADE)
Any undesirable occurrence involving medications. The two most common categories are
medication errors and adverse drug reactions (ADR)
Adverse drug reaction (ADR)
Any reaction to a drug that is unexpected and undesirable and occurs at therapeutic
drug dosages
Pharmacologic reaction
Known and predictable reaction
Hypersensitivity reaction
Allergic reaction - Involves the patients immune system; patient specific and immunological
response
Idiosyncratic reaction
Verified Answers
How do drugs exert actions?
Receptors, enzymes and nonselective physiology
Receptors
Reactive site on surface or inside cell (molecular structure of drug is critical)
What two ways do drugs interact with receptors
Elicit or block physiologic response
Affinity:
Degree which a drug attaches to and binds with a receptor; drug with the best "fit" and
strongest affinity will elicit the greatest response
Enzymes
Drugs bind to enzyme and either inhibit (more common) or enhance (less common) the action
of a specific enzyme // this process is called selective interaction
Nonselective interactions
Nonspecific mechanism of action ; Drugs do not interact with receptors or enzymes --> Their
main targets are cell membranes and various cellular processes such as metabolic activities ;
These drugs can either physically interfere with or chemically alter cellular structures of
processes ; Some cancer and antibiotic do this
Agonist
,Drug binds to the receptor; there IS a response
Partial agonist (agonist-antagonist)
Drug binds to the receptor; the response is diminished compared with the elicited by an agonist
Antagonist
Drug binds to the receptor; there is NO response. Drug prevents binding of agonists
Competitive antagonist
Drug competes with the agonist for binding to the receptor. If it binds, there is NO response
Noncompetitive antagonist
Drug combines with different parts of the receptor and inactivates it; agonist then has no effect
Pharmacotherapeutics
The clinical use of drugs to prevent and treat diseases
Acute therapy
Intensive drug treatment for acutely ill, needed to sustain life
Maintenance therapy
Prevents progression of a disease, treats chronic illnesses
Supplemental (replacement) therapy
Supplies body with substance needed to maintain normal function. I.e. - Insulin for
diabetic, iron for anemia
Palliative therapy
Make Pt comfortable, provide relief from pain, stress of serious illness. I.e. - opioids for end of
life
Supportive therapy
, Maintain integrity of body functions while Pt recovers from illness/trauma. I.e. - electrolytes to
prevent dehydration due to vomit/diarrhea
Prophylactic therapy
Prevent illness. I.e. - preoperative antibiotic. Vaccine to traveler
Empiric therapy
Based on clinical probabilities, when a certain pathologic condition has high likelihood of
occurrence based on the patient's initial presenting symptoms. Ex] Use of antibiotics active
against the organism most commonly associated with specific infection before the results of the
culture and sensitivity reports are available
Monitoring:
Therapy implemented, effectiveness must be evaluated. I.e. - Giving antihypertensives
and monitoring blood pressure
Adverse drug event (ADE)
Any undesirable occurrence involving medications. The two most common categories are
medication errors and adverse drug reactions (ADR)
Adverse drug reaction (ADR)
Any reaction to a drug that is unexpected and undesirable and occurs at therapeutic
drug dosages
Pharmacologic reaction
Known and predictable reaction
Hypersensitivity reaction
Allergic reaction - Involves the patients immune system; patient specific and immunological
response
Idiosyncratic reaction
