NURS 1060: EXAM #3 QUESTIONS AND ANSWERS WITH
COMPLETE SOLUTIONS GRADED A++ LATEST UPDATE
Drug-Drug Interactions
Interactions can occur whenever a patient takes more than one drug, some interactions
are intended and desired or unintended and undesired.
*Creation of a unique or unknown response.
(Ex.: Alcohol with barbiturate can be lethal).
Consequences of drug-drug interactions
Intensification of effects (Increased therapeutic or adverse effects), Reduction of effects
(Reduced therapeutic or adverse effects), Can create an unknown chemical when
mixing two drugs that will be given parenteral (Check a drug compatibility chart).
Inhibitory
Interactions that result in reduced drug effects (Reduced therapeutic effects).
Basic mechanisms of drug-drug interactions: Pharmacokinetic interaction
examples
-Altered absorption: Drugs thats depress peristalsis, Drugs that induce vomiting.
-Altered distribution: Competition for protein binding.
-Altered metabolism: Phenobarbital is an inducing agent that increases the
synthesis/production of hepatic cytochrome P450 (CYP) enzymes responsible for the
metabolism of many drugs.
-Altered renal excretion: Drugs can alter filtration, reabsorption, active secretion.
Never combine drugs in the same
,Container or syringe without establishing compatibility.
Interactions that involve P-Glycoproteins (PGP's)-
Transmembrane protein that transports a wide variety of drugs out of cells.
Reduction or increased PGP
-Intestinal epithelium: Affects absorption.
-Placenta: affects drug export from placental cells to maternal blood.
-Blood-brain barrier: Affects drug export from cells of brain capillaries into the blood.
-Liver: Affects drug export from liver into bile.
-Kidney tubules: Affects drug export from renal tubular cells into the urine.
At the same receptor
Antagonist/Agonist.
At seperate receptor sites
May be potentiative.
(Ex.: Both warfarin and aspirin suppress blood clotting and the combination may
increase the risk of bleeding).
A potentiative effect is
One in which one drug intensifies the effects of another.
Minimizing adverse drug-drug interactions
Minimize number of drugs a patient receives, take a thorough drug history, adjust the
dosage when metabolizing inducers are added or deleted, be vigilant when patient is
taking a drug with a drug with low therapeutic index.
Examples of drug-food interactions
, Decreased absorption.
-Calcium-containing foods: Milk and Tetracycline.. Calcium binds to tetracycline and is
insoluble.
-High fiber foods.
Example of reduced adverse effects in drug-drug interactions
Naloxone to treat morphine overdose. Morphine reduces respirations- give naloxone to
block morphine receptor binding.
Example of inhibitory (Reduced therapeutic effects) in drug-drug interactions
Propranolol is a cardiovascular drug and Albuterol is a bronchodilator to treat asthma.
Propranolol reduces albuterol effects.
Example of increased therapeutic effects in drug-drug interactions
Sulbactam and ampicillin are two seperate drugs combined into one antibiotic PCN +
Beta Lactamase Inhibitor.
Sulbactam is a beta lactamase inhibitor. Ampicillin is a broad spectrum penicillin.
Combination prolongs and intensifies ampicillin effect.
Example of increased adverse effects in drug-drug interactions
Aspirin (Antiplatelet) and Warfarin (Anticoagulant) put you at risk for major bleeding.
Some drugs must be taken on
An empty stomach. The absorption of some drugs can be significantly reduced by food.
Taken on an empty stomach equates to 1 hour before a meal or 2 hours after a meal.
-Other drugs should be taken with food.
The grapefruit juice effect
COMPLETE SOLUTIONS GRADED A++ LATEST UPDATE
Drug-Drug Interactions
Interactions can occur whenever a patient takes more than one drug, some interactions
are intended and desired or unintended and undesired.
*Creation of a unique or unknown response.
(Ex.: Alcohol with barbiturate can be lethal).
Consequences of drug-drug interactions
Intensification of effects (Increased therapeutic or adverse effects), Reduction of effects
(Reduced therapeutic or adverse effects), Can create an unknown chemical when
mixing two drugs that will be given parenteral (Check a drug compatibility chart).
Inhibitory
Interactions that result in reduced drug effects (Reduced therapeutic effects).
Basic mechanisms of drug-drug interactions: Pharmacokinetic interaction
examples
-Altered absorption: Drugs thats depress peristalsis, Drugs that induce vomiting.
-Altered distribution: Competition for protein binding.
-Altered metabolism: Phenobarbital is an inducing agent that increases the
synthesis/production of hepatic cytochrome P450 (CYP) enzymes responsible for the
metabolism of many drugs.
-Altered renal excretion: Drugs can alter filtration, reabsorption, active secretion.
Never combine drugs in the same
,Container or syringe without establishing compatibility.
Interactions that involve P-Glycoproteins (PGP's)-
Transmembrane protein that transports a wide variety of drugs out of cells.
Reduction or increased PGP
-Intestinal epithelium: Affects absorption.
-Placenta: affects drug export from placental cells to maternal blood.
-Blood-brain barrier: Affects drug export from cells of brain capillaries into the blood.
-Liver: Affects drug export from liver into bile.
-Kidney tubules: Affects drug export from renal tubular cells into the urine.
At the same receptor
Antagonist/Agonist.
At seperate receptor sites
May be potentiative.
(Ex.: Both warfarin and aspirin suppress blood clotting and the combination may
increase the risk of bleeding).
A potentiative effect is
One in which one drug intensifies the effects of another.
Minimizing adverse drug-drug interactions
Minimize number of drugs a patient receives, take a thorough drug history, adjust the
dosage when metabolizing inducers are added or deleted, be vigilant when patient is
taking a drug with a drug with low therapeutic index.
Examples of drug-food interactions
, Decreased absorption.
-Calcium-containing foods: Milk and Tetracycline.. Calcium binds to tetracycline and is
insoluble.
-High fiber foods.
Example of reduced adverse effects in drug-drug interactions
Naloxone to treat morphine overdose. Morphine reduces respirations- give naloxone to
block morphine receptor binding.
Example of inhibitory (Reduced therapeutic effects) in drug-drug interactions
Propranolol is a cardiovascular drug and Albuterol is a bronchodilator to treat asthma.
Propranolol reduces albuterol effects.
Example of increased therapeutic effects in drug-drug interactions
Sulbactam and ampicillin are two seperate drugs combined into one antibiotic PCN +
Beta Lactamase Inhibitor.
Sulbactam is a beta lactamase inhibitor. Ampicillin is a broad spectrum penicillin.
Combination prolongs and intensifies ampicillin effect.
Example of increased adverse effects in drug-drug interactions
Aspirin (Antiplatelet) and Warfarin (Anticoagulant) put you at risk for major bleeding.
Some drugs must be taken on
An empty stomach. The absorption of some drugs can be significantly reduced by food.
Taken on an empty stomach equates to 1 hour before a meal or 2 hours after a meal.
-Other drugs should be taken with food.
The grapefruit juice effect
