Study Guide for Pharm
Fall 2025
,1. What is the objective of drug therapy?
To provide maximum benefit with minimum harm!!!
2. What factors affect drug absorption?
Absorption is the movement of a drug from its site of administration into the blood.
, -Rate of Dissolution: Before a drug can be absorbed, it must first dissolve. Drugs in
formulations that allow rapid dissolution have a faster onset than drugs formulated for
slow dissoulution. Ex. Enteric Coated or XL.
-Surface Area: The larger the surface area, the faster the absorption will be. Ex.
Small intestine has larger sueface area than the stomach because of villi. -Blood Flow:
Drugs are absorbed more rapidly from sites where blood flow is high. This is because
blood containing newly absorbed drug will be replaced rapidly by drug-free blood,
thereby maintaining a large gradient between the concentration of drug outside the
blood and the concentration of the drug in the blood. The greater the concentration
gradient, the more rapid absorption will be. -Lipid solubility: Highly lipid soluble drugs
are absorbed more rapidly than drugs whose lipid solubility is low. This is because
lipid-soluble drugs can readily cross the membranes that separate them from the
blood, whereas drugs of low lipid solubility cannot.
-pH partitioning: Difference in pH causes faster absorption
3. What problems with medication effectiveness do we encounter with bloodbrain-
barrier?
Blood-brain barrior- must be lipid soluble to pass through the BBB or have a transport
system. BBB protects brain from some toxic substances. This makes it harder to treat
infections or other problems where medication needs to reach the brain. BBB is not
developed at birth so newborns are more sensitive and vulnerable to CNS poisons.
Placenta also does not protect- the placenta does not “filter” medications to protect the
developing fetus.
4. Explain and know how to figure drug half life.
Time required for the amount of drug in the body to decrease by 50%. May have
extremely short or relatively long half lives- will vary by medication. Half life helps to
determine the dosing interval. Ex. The half life of morphine is 3 hours. If a patient
receives 4mg of morphine, how much morphine will remain in 9 hours? 4>2>1>.5
5. What is the first pass effect? What routes of administration bypass the first pass
effect?
Rapid hepatic inactivation of certain oral drugs. GI tract goes directly to liver. May
bypass the first pass effect by giving in a parenteral route.
6. Why does grapefruit affect metabolism of certain drugs?
Grapefruit juice can inhibit the metabolism of certain drugs by raising the blood levels.
It is not seen with other citric fruits. If a patient does drink grapefruit juice they must
stay consistent while on a medication that is affected by this juice otherwise the blood
levels will rise.
7. What is tolerance to a drug?
Tolerance can be defined as decreased responsiveness to a drug as a result of repeated
drug administration.
8. What is a teratogen?
, A teratogen is a harmful agent to fetus and can cause birth defects or even a
miscarriage. Teratogens can include smoking, alcohol, pollution, radiation, and certain
medications.
9. Look over the pregnancy risk categories.
The pregnancy risk categories include categories A, B, C, D, and X.
A: Remote risk of fetal harm
B: Slightly more of a risk than A
C: Greater risk than B, look to see is risks outweigh benefits D:
Proven risk of fetal harm, do risks outweigh benefits?
X: Proven risk of fetal harm, WILL cause spontaneous abortion, risks do NOT outweigh
benefits.
10. Why are many pediatric dosages weight based (why not 1 dose for all like adult
meds)?
Pediatric dosages are weight based because their bodies and organ systems are not fully
developed yet like an adult. There cannot be 1 dose for all the med like adult dosing
because children all grow at different rates. What might be a therapeutic dose for one
child could be a toxic dose for another.
11. What are the pharmacokinetic changes in the elderly?
In the elderly there is progressive decline in organ function. This decline can alter the
absorption, distribution, metabolism, and excretion of drugs. Mainly, these
pharmacokinetic changes increase drug sensitivity due to reduced hepatic and renal
drug elimination.
-Absorption: Rate of absorption is slowed due to delayed gastric emptying and reduced
blood flow
-Distribution: Increased percent body fat, decreased percent lean body mass, decreased
total body water, and reduced concentration of serum albumin are all factors that alter
drug distribution in the elderly.
-Metabolism: Decreases due to decreased liver function
-Excretion: Drug accumulation due to decreased renal function
12. What are cholinergic and adrenergic receptors? What happens if you stimulate them
or suppress them?
Adrenergic involves the use of the neurotransmitters epinephrine and norepinehprine
while cholinergic involves acetylcholine. Adrenergic is called the sympathetic line (SNS)
while cholinergic is called the parasympathetic line (PNS). Nicotinic and muscarinic
receptors are part of the cholinergic line while alpha and beta receptors are involved in
the adrenergic line.
The effects of cholinergic stimulation include: bradycardia, increased secretion from
sweat, salivary, bronchial and gastric glands, contraction of smooth muscle and papillary
constriction. Cholinergic suppression include: tachycardia, decreased bodily excretions
(dry mouth, not sweating, urinary retention) and blurred vision. Adrenergic stimulants
cause homeostasis by stopping bleeding with vasoconstriction, nasal decongestion,
Fall 2025
,1. What is the objective of drug therapy?
To provide maximum benefit with minimum harm!!!
2. What factors affect drug absorption?
Absorption is the movement of a drug from its site of administration into the blood.
, -Rate of Dissolution: Before a drug can be absorbed, it must first dissolve. Drugs in
formulations that allow rapid dissolution have a faster onset than drugs formulated for
slow dissoulution. Ex. Enteric Coated or XL.
-Surface Area: The larger the surface area, the faster the absorption will be. Ex.
Small intestine has larger sueface area than the stomach because of villi. -Blood Flow:
Drugs are absorbed more rapidly from sites where blood flow is high. This is because
blood containing newly absorbed drug will be replaced rapidly by drug-free blood,
thereby maintaining a large gradient between the concentration of drug outside the
blood and the concentration of the drug in the blood. The greater the concentration
gradient, the more rapid absorption will be. -Lipid solubility: Highly lipid soluble drugs
are absorbed more rapidly than drugs whose lipid solubility is low. This is because
lipid-soluble drugs can readily cross the membranes that separate them from the
blood, whereas drugs of low lipid solubility cannot.
-pH partitioning: Difference in pH causes faster absorption
3. What problems with medication effectiveness do we encounter with bloodbrain-
barrier?
Blood-brain barrior- must be lipid soluble to pass through the BBB or have a transport
system. BBB protects brain from some toxic substances. This makes it harder to treat
infections or other problems where medication needs to reach the brain. BBB is not
developed at birth so newborns are more sensitive and vulnerable to CNS poisons.
Placenta also does not protect- the placenta does not “filter” medications to protect the
developing fetus.
4. Explain and know how to figure drug half life.
Time required for the amount of drug in the body to decrease by 50%. May have
extremely short or relatively long half lives- will vary by medication. Half life helps to
determine the dosing interval. Ex. The half life of morphine is 3 hours. If a patient
receives 4mg of morphine, how much morphine will remain in 9 hours? 4>2>1>.5
5. What is the first pass effect? What routes of administration bypass the first pass
effect?
Rapid hepatic inactivation of certain oral drugs. GI tract goes directly to liver. May
bypass the first pass effect by giving in a parenteral route.
6. Why does grapefruit affect metabolism of certain drugs?
Grapefruit juice can inhibit the metabolism of certain drugs by raising the blood levels.
It is not seen with other citric fruits. If a patient does drink grapefruit juice they must
stay consistent while on a medication that is affected by this juice otherwise the blood
levels will rise.
7. What is tolerance to a drug?
Tolerance can be defined as decreased responsiveness to a drug as a result of repeated
drug administration.
8. What is a teratogen?
, A teratogen is a harmful agent to fetus and can cause birth defects or even a
miscarriage. Teratogens can include smoking, alcohol, pollution, radiation, and certain
medications.
9. Look over the pregnancy risk categories.
The pregnancy risk categories include categories A, B, C, D, and X.
A: Remote risk of fetal harm
B: Slightly more of a risk than A
C: Greater risk than B, look to see is risks outweigh benefits D:
Proven risk of fetal harm, do risks outweigh benefits?
X: Proven risk of fetal harm, WILL cause spontaneous abortion, risks do NOT outweigh
benefits.
10. Why are many pediatric dosages weight based (why not 1 dose for all like adult
meds)?
Pediatric dosages are weight based because their bodies and organ systems are not fully
developed yet like an adult. There cannot be 1 dose for all the med like adult dosing
because children all grow at different rates. What might be a therapeutic dose for one
child could be a toxic dose for another.
11. What are the pharmacokinetic changes in the elderly?
In the elderly there is progressive decline in organ function. This decline can alter the
absorption, distribution, metabolism, and excretion of drugs. Mainly, these
pharmacokinetic changes increase drug sensitivity due to reduced hepatic and renal
drug elimination.
-Absorption: Rate of absorption is slowed due to delayed gastric emptying and reduced
blood flow
-Distribution: Increased percent body fat, decreased percent lean body mass, decreased
total body water, and reduced concentration of serum albumin are all factors that alter
drug distribution in the elderly.
-Metabolism: Decreases due to decreased liver function
-Excretion: Drug accumulation due to decreased renal function
12. What are cholinergic and adrenergic receptors? What happens if you stimulate them
or suppress them?
Adrenergic involves the use of the neurotransmitters epinephrine and norepinehprine
while cholinergic involves acetylcholine. Adrenergic is called the sympathetic line (SNS)
while cholinergic is called the parasympathetic line (PNS). Nicotinic and muscarinic
receptors are part of the cholinergic line while alpha and beta receptors are involved in
the adrenergic line.
The effects of cholinergic stimulation include: bradycardia, increased secretion from
sweat, salivary, bronchial and gastric glands, contraction of smooth muscle and papillary
constriction. Cholinergic suppression include: tachycardia, decreased bodily excretions
(dry mouth, not sweating, urinary retention) and blurred vision. Adrenergic stimulants
cause homeostasis by stopping bleeding with vasoconstriction, nasal decongestion,
