PHARMACOLOGY MIDTERMS COMPLETE DETAILED STUDY GUIDE GRADED A+
2022/2023 UPDATE
Pharmacokinetics:
• Understand the implications of changing renal function on creatinine and drug dosing.
Renal disease interacts with drugs in three main ways. Firstly, patients with renal disease may be more vulnerable to a
given drug effect (patient susceptibility). Secondly, a drug effect may be exaggerated or attenuated in patients with renal
disease (pharmacodynamic change). Thirdly, and most importantly, some drugs have higher steady-state concentrations
when given at usual doses to patients with renal disease (pharmacokinetic changes).
Serum creatinine is the most commonly used analyte in the evaluation of renal function, and equations using serum
creatinine concentration are the basis of most estimates of GFR
• What is the impact of the following on drug levels and dosing:
o Cirrhosis The liver is the main organ for metabolism and detoxification of endogenous and exogenous substances.
Several pathophysiological changes that occur in liver cirrhosis influence this detoxification of exogenous substances, that
is, drug pharmacokinetics.
o Protein binding Drugs can form reversible bonds with various proteins in the body. Of all the proteins with which
drugs can bind, plasma albumin is the most important. Like other proteins, albumin is a large molecule. Because of its size,
albumin is too large to leave the bloodstream.
Even though a drug can bind albumin, only some molecules will be bound at any moment. The percentage of drug
molecules that are
bound is determined by the strength of the attraction between albumin and the drug
An important consequence of protein binding is restriction of drug distribution. Because albumin is too large to leave
the bloodstream, drug molecules that are bound to albumin cannot leave either. As a result, bound molecules cannot reach
their sites of action or undergo metabolism or excretion until the drug-protein bond is broken so that the drug is free to
leave the circulation. In addition to restricting drug distribution, protein binding can be a source of drug interactions.
Each molecule of albumin has only a few sites to which drug molecules can bind. Because the number of binding sites is
limited, drugs with the ability to bind albumin will compete with one another for those sites. As a result, one drug can
displace another from albumin, causing the free concentration of the displaced drug to rise, thus increasing the intensity
of drug responses. If plasma drug levels rise sufficiently, toxicity can result
o Drug interactions Drug-drug interactions can occur whenever a patient takes two or more drugs. Some
interactions are both intended and desired, as when we combine drugs to treat hypertension. In contrast, some interactions
are both unintended and undesired.
Consequences of Drug-Drug Interactions When two drugs interact, there are three possible outcomes:
(1) one drug may intensify the effects of the other,
(2) one drug may reduce the effects of the other, or
(3) the combination may produce a new response not seen with either drug alone.
o Half-life - Drug half-life is defined as the time required for the amount of drug in the body to decrease by 50%. A
few drugs have half-lives that are extremely short—on the order of minutes or less. In contrast, the half-lives of some drugs
exceed 1 week.
Routes of Administration and Dosage Forms:
• Understand the different routes of administration and dosage forms and some of the challenges and
benefits associated with these routes and forms.
How drugs are administered A drug’s administration route influences the quantity given and the rate at which the drug is
absorbed and distributed. These variables affect the drug’s action and the patient’s response.
Routes of administration include:
• buccal, sublingual, translingual: certain drugs are given buccally (in the pouch between the cheek and gum),
sublingually (under the tongue), or translingually (on the tongue) to speed their absorption or to
prevent their destruction or transformation in the stomach or small intestine
• gastric: this route allows direct instillation of medication into the GI system of patients who can’t ingest the drug orally
• intradermal: substances are injected into the skin (dermis); this route is used mainly for diagnostic purposes when
testing for allergies or tuberculosis \
• intramuscular: this route allows drugs to be injected directly into various muscle groups at varying tissue depths; it’s
used to give aqueous suspensions and solutions in oil, immunizations, and medications that
aren’t available in oral form
• intravenous: the I.V. route allows injection of substances (drugs, fluids, blood or blood products, and diagnostic contrast
agents) directly into the bloodstream through a vein; administration can range from a single dose to an ongoing infusion
delivered with great precision
• oral: this is usually the safest, most convenient, and least expensive route; drugs are administered to patients who are
conscious and can swallow
• rectal and vaginal: suppositories, ointments, creams, gels, and tablets may be instilled into the rectum or vagina to
treat local irritation or infection; some drugs applied to the mucosa of the rectum or vagina can be absorbed systemically
• respiratory: drugs that are available as gases can be administered into the respiratory system; drugs given by
,inhalation are rapidly absorbed, and medications given by such devices as the metered-dose inhaler can be self-
administered, or drugs can be administered directly into the lungs through an endotracheal tube in emergency situations
• subcutaneous (subQ): with the subQ route, small amounts of a drug are injected beneath the dermis and into the
subcutaneous tissue, usually in the patient’s upper arm, thigh, or abdomen • topical: this route is used to deliver a drug
through the skin or a mucous membrane; it’s used for most dermatologic, ophthalmic, otic, and nasal preparations. Drugs
may also be given as specialized infusions injected directly into a specific site in the patient’s body, such as an epidural
,infusion (into the epidural space), intrathecal infusion (into the cerebrospinal fluid), intrapleural infusion (into the pleural
cavity), intraperitoneal infusion (into the peritoneal cavity), intraosseous infusion (into the rich vascular network of a long
bone), and intraarticular infusion (into a joint). New drug development In the past, drugs were found by tri
• Understand when it is OK to crush (or not crush) certain dosage forms and why.
Generally, meds that should not be crushed fall into one of these categories:
• Sustained-release tablets, which can be composed of multiple layers for different drug release times, as can beads within
capsules. Some of the more common prefixes or suffixes for sustained-release, controlled-release, or controlled-delivery products
include: 12-hour, 24-hour, CC, CD, CR, ER, LA, Retard, SA, Slo-, SR, XL, XR, or XT.
• Enteric-coated tablets, which are formulated because certain drugs can be irritating to the stomach or are degraded by stomach
acid. By enteric-coating tablets or capsule beads, the drug’s release can be delayed until it reaches the small intestine. Prefixes
include EN- and EC-.
• Which routes of administration have the fastest and slowest rates of absorption?
• Know the relative onset, monitoring and appropriate use of various dosage forms
including: o Patches (ie; fentanyl, rivastigmine)
o Suppositories (ie; acetaminophen)
o Sublingual tablets
o Tablets
o Liquid (know common measures)
o Injectables
o Sublingual
o Nasogastric
o Elixir (contains alcohol)
(page 85)
Route Barriers to Absorption Advantages Disadvantages
Absorption Pattern
Therapeutics:
Gastrointestinal, Cardiac, Respiratory, Neurology, Musculoskeletal
Understand the mechanism of action, side effects, appropriate use and contraindications for the classes of drugs
and individual drugs listed below.
Also, know the key patient education points including cautions, expected effects, and appropriate use (with food,
empty stomach, etc.).
=================================GASTROINTESTINAL==
===============================
• Anti-diarrheals (diphenoxylate HCl with atropine sulfate(Lomotil), loperamide (Imodium
), bismuth subsalicylate[Pepto-Bismol, others].
Antidiarrheal drugs fall into two major groups: (1) specific antidiarrheal drugs and (2)
nonspecific antidiarrheal drugs. The specific agents are drugs that treat the underlying
cause of diarrhea. Included in this group are antiinfective drugs and drugs used to correct
malabsorption syndromes. Nonspecific antidiarrheals are agents that act on or within the
bowel to provide symptomatic relief; these drugs do not influence the underlying cause.
Opioids are our most effective antidiarrheal agents. By activating opioid receptors in
the GI tract, these drugs decrease intestinal motility and thereby slow intestinal transit,
which allows more time for absorption of fluid and electrolytes. In addition, activation of
opioid receptors decreases secretion of fluid into the small intestine and increases
absorption of fluid and salt. The net effect is to present the large intestine with less water.
As a result, the fluidity and volume of stools are reduced, as is the frequency of defecation
, Several opioid preparations—diphenoxylate, difenoxin, loperamide, paregoric, and opium
tincture—are approved for diarrhea. Of these, diphenoxylate [Lomotil, others] and
loperamide [Imodium, others] are the most frequently employed
Bismuth subsalicylate [Pepto-Bismol, others] is effective for the prevention and
treatment of mild diarrhea. For prevention, the dosage is two 262-mg tablets 4 times a day
for up to 3 weeks. For treatment, the dosage is 2 tablets every 30 minutes for up to
eight doses. Users should be aware that the drug may blacken stools and the tongue.
• Laxatives (fiber, osmotics, stimulants, other)
Laxatives are used to ease or stimulate defecation. These agents can soften the stool,
increase stool volume, hasten fecal passage through the intestine, and facilitate evacuation
from the rectum. When properly employed, laxatives are valuable medications. However,
these agents are also subject to abuse. Misuse of laxatives is largely the result of
misconceptions about what constitutes normal bowel function. Before we talk about
laxatives, we need to distinguish between two terms: laxative effect and catharsis. The term
laxative ef ect refers to production of a soft, formed stool over a period of 1 or more days. In
contrast, the term catharsis refers to a prompt, fluid evacuation of the bowel. Hence a
laxative effect is slower and relatively mild, whereas catharsis is relatively fast and intense.
Traditionally, laxatives have been classified according to general mechanism of
action. This scheme has four major categories:
(1) bulk-forming laxatives,
The bulk-forming laxatives (e.g., methylcellulose, psyllium, polycarbophil) have actions
and effects much like those of dietary fiber. These agents consist of natural or
semisynthetic polysaccharides and celluloses derived from grains and other plant
material. The bulk-forming agents belong to our therapeutic group III, producing a soft,
formed stool after 1 to 3 days of use.
• Mechanism of Action
Bulk-forming agents have the same effect on bowel function as dietary fiber. After
ingestion, these agents, which are nondigestible and nonabsorbable, swell in water
to form a viscous solution or gel, thereby softening the fecal mass and increasing
its bulk. Fecal volume may be further enlarged by growth of colonic bacteria, which
can utilize these materials as nutrients. Transit through the intestine is hastened
because swelling of the fecal mass stretches the intestinal wall and thereby
stimulates peristalsis.
• Indications
Bulk-forming laxatives are preferred agents for temporary treatment of
constipation. Also, they are widely used in patients with diverticulosis and irritable
bowel syndrome. In addition, by altering fecal consistency, they can provide
symptomatic relief of diarrhea and can reduce discomfort and inconvenience for
patients with an ileostomy or colostomy.
• Adverse Effects
Untoward effects are minimal. Because the bulk-forming agents are not absorbed,
systemic reactions are rare. Esophageal obstruction can occur if they are swallowed
in the absence of sufficient fluid. Accordingly, bulk-forming laxatives should be
administered with a full glass of water or juice. If their passage through the
intestine is impeded, they may produce intestinal obstruction or impaction.
Accordingly, they should be avoided if there is narrowing of the intestinal lumen.
• Preparations, Dosage, and Administration
Psyllium (prepared from Plantago seed), methylcellulose, and polycarbophil are the
principal bulk-forming laxatives. All three preparations should be administered with
a full glass of water or juice. (Dosages and trade names are shown in Table
63.4.)
(2) surfactant laxatives,
2022/2023 UPDATE
Pharmacokinetics:
• Understand the implications of changing renal function on creatinine and drug dosing.
Renal disease interacts with drugs in three main ways. Firstly, patients with renal disease may be more vulnerable to a
given drug effect (patient susceptibility). Secondly, a drug effect may be exaggerated or attenuated in patients with renal
disease (pharmacodynamic change). Thirdly, and most importantly, some drugs have higher steady-state concentrations
when given at usual doses to patients with renal disease (pharmacokinetic changes).
Serum creatinine is the most commonly used analyte in the evaluation of renal function, and equations using serum
creatinine concentration are the basis of most estimates of GFR
• What is the impact of the following on drug levels and dosing:
o Cirrhosis The liver is the main organ for metabolism and detoxification of endogenous and exogenous substances.
Several pathophysiological changes that occur in liver cirrhosis influence this detoxification of exogenous substances, that
is, drug pharmacokinetics.
o Protein binding Drugs can form reversible bonds with various proteins in the body. Of all the proteins with which
drugs can bind, plasma albumin is the most important. Like other proteins, albumin is a large molecule. Because of its size,
albumin is too large to leave the bloodstream.
Even though a drug can bind albumin, only some molecules will be bound at any moment. The percentage of drug
molecules that are
bound is determined by the strength of the attraction between albumin and the drug
An important consequence of protein binding is restriction of drug distribution. Because albumin is too large to leave
the bloodstream, drug molecules that are bound to albumin cannot leave either. As a result, bound molecules cannot reach
their sites of action or undergo metabolism or excretion until the drug-protein bond is broken so that the drug is free to
leave the circulation. In addition to restricting drug distribution, protein binding can be a source of drug interactions.
Each molecule of albumin has only a few sites to which drug molecules can bind. Because the number of binding sites is
limited, drugs with the ability to bind albumin will compete with one another for those sites. As a result, one drug can
displace another from albumin, causing the free concentration of the displaced drug to rise, thus increasing the intensity
of drug responses. If plasma drug levels rise sufficiently, toxicity can result
o Drug interactions Drug-drug interactions can occur whenever a patient takes two or more drugs. Some
interactions are both intended and desired, as when we combine drugs to treat hypertension. In contrast, some interactions
are both unintended and undesired.
Consequences of Drug-Drug Interactions When two drugs interact, there are three possible outcomes:
(1) one drug may intensify the effects of the other,
(2) one drug may reduce the effects of the other, or
(3) the combination may produce a new response not seen with either drug alone.
o Half-life - Drug half-life is defined as the time required for the amount of drug in the body to decrease by 50%. A
few drugs have half-lives that are extremely short—on the order of minutes or less. In contrast, the half-lives of some drugs
exceed 1 week.
Routes of Administration and Dosage Forms:
• Understand the different routes of administration and dosage forms and some of the challenges and
benefits associated with these routes and forms.
How drugs are administered A drug’s administration route influences the quantity given and the rate at which the drug is
absorbed and distributed. These variables affect the drug’s action and the patient’s response.
Routes of administration include:
• buccal, sublingual, translingual: certain drugs are given buccally (in the pouch between the cheek and gum),
sublingually (under the tongue), or translingually (on the tongue) to speed their absorption or to
prevent their destruction or transformation in the stomach or small intestine
• gastric: this route allows direct instillation of medication into the GI system of patients who can’t ingest the drug orally
• intradermal: substances are injected into the skin (dermis); this route is used mainly for diagnostic purposes when
testing for allergies or tuberculosis \
• intramuscular: this route allows drugs to be injected directly into various muscle groups at varying tissue depths; it’s
used to give aqueous suspensions and solutions in oil, immunizations, and medications that
aren’t available in oral form
• intravenous: the I.V. route allows injection of substances (drugs, fluids, blood or blood products, and diagnostic contrast
agents) directly into the bloodstream through a vein; administration can range from a single dose to an ongoing infusion
delivered with great precision
• oral: this is usually the safest, most convenient, and least expensive route; drugs are administered to patients who are
conscious and can swallow
• rectal and vaginal: suppositories, ointments, creams, gels, and tablets may be instilled into the rectum or vagina to
treat local irritation or infection; some drugs applied to the mucosa of the rectum or vagina can be absorbed systemically
• respiratory: drugs that are available as gases can be administered into the respiratory system; drugs given by
,inhalation are rapidly absorbed, and medications given by such devices as the metered-dose inhaler can be self-
administered, or drugs can be administered directly into the lungs through an endotracheal tube in emergency situations
• subcutaneous (subQ): with the subQ route, small amounts of a drug are injected beneath the dermis and into the
subcutaneous tissue, usually in the patient’s upper arm, thigh, or abdomen • topical: this route is used to deliver a drug
through the skin or a mucous membrane; it’s used for most dermatologic, ophthalmic, otic, and nasal preparations. Drugs
may also be given as specialized infusions injected directly into a specific site in the patient’s body, such as an epidural
,infusion (into the epidural space), intrathecal infusion (into the cerebrospinal fluid), intrapleural infusion (into the pleural
cavity), intraperitoneal infusion (into the peritoneal cavity), intraosseous infusion (into the rich vascular network of a long
bone), and intraarticular infusion (into a joint). New drug development In the past, drugs were found by tri
• Understand when it is OK to crush (or not crush) certain dosage forms and why.
Generally, meds that should not be crushed fall into one of these categories:
• Sustained-release tablets, which can be composed of multiple layers for different drug release times, as can beads within
capsules. Some of the more common prefixes or suffixes for sustained-release, controlled-release, or controlled-delivery products
include: 12-hour, 24-hour, CC, CD, CR, ER, LA, Retard, SA, Slo-, SR, XL, XR, or XT.
• Enteric-coated tablets, which are formulated because certain drugs can be irritating to the stomach or are degraded by stomach
acid. By enteric-coating tablets or capsule beads, the drug’s release can be delayed until it reaches the small intestine. Prefixes
include EN- and EC-.
• Which routes of administration have the fastest and slowest rates of absorption?
• Know the relative onset, monitoring and appropriate use of various dosage forms
including: o Patches (ie; fentanyl, rivastigmine)
o Suppositories (ie; acetaminophen)
o Sublingual tablets
o Tablets
o Liquid (know common measures)
o Injectables
o Sublingual
o Nasogastric
o Elixir (contains alcohol)
(page 85)
Route Barriers to Absorption Advantages Disadvantages
Absorption Pattern
Therapeutics:
Gastrointestinal, Cardiac, Respiratory, Neurology, Musculoskeletal
Understand the mechanism of action, side effects, appropriate use and contraindications for the classes of drugs
and individual drugs listed below.
Also, know the key patient education points including cautions, expected effects, and appropriate use (with food,
empty stomach, etc.).
=================================GASTROINTESTINAL==
===============================
• Anti-diarrheals (diphenoxylate HCl with atropine sulfate(Lomotil), loperamide (Imodium
), bismuth subsalicylate[Pepto-Bismol, others].
Antidiarrheal drugs fall into two major groups: (1) specific antidiarrheal drugs and (2)
nonspecific antidiarrheal drugs. The specific agents are drugs that treat the underlying
cause of diarrhea. Included in this group are antiinfective drugs and drugs used to correct
malabsorption syndromes. Nonspecific antidiarrheals are agents that act on or within the
bowel to provide symptomatic relief; these drugs do not influence the underlying cause.
Opioids are our most effective antidiarrheal agents. By activating opioid receptors in
the GI tract, these drugs decrease intestinal motility and thereby slow intestinal transit,
which allows more time for absorption of fluid and electrolytes. In addition, activation of
opioid receptors decreases secretion of fluid into the small intestine and increases
absorption of fluid and salt. The net effect is to present the large intestine with less water.
As a result, the fluidity and volume of stools are reduced, as is the frequency of defecation
, Several opioid preparations—diphenoxylate, difenoxin, loperamide, paregoric, and opium
tincture—are approved for diarrhea. Of these, diphenoxylate [Lomotil, others] and
loperamide [Imodium, others] are the most frequently employed
Bismuth subsalicylate [Pepto-Bismol, others] is effective for the prevention and
treatment of mild diarrhea. For prevention, the dosage is two 262-mg tablets 4 times a day
for up to 3 weeks. For treatment, the dosage is 2 tablets every 30 minutes for up to
eight doses. Users should be aware that the drug may blacken stools and the tongue.
• Laxatives (fiber, osmotics, stimulants, other)
Laxatives are used to ease or stimulate defecation. These agents can soften the stool,
increase stool volume, hasten fecal passage through the intestine, and facilitate evacuation
from the rectum. When properly employed, laxatives are valuable medications. However,
these agents are also subject to abuse. Misuse of laxatives is largely the result of
misconceptions about what constitutes normal bowel function. Before we talk about
laxatives, we need to distinguish between two terms: laxative effect and catharsis. The term
laxative ef ect refers to production of a soft, formed stool over a period of 1 or more days. In
contrast, the term catharsis refers to a prompt, fluid evacuation of the bowel. Hence a
laxative effect is slower and relatively mild, whereas catharsis is relatively fast and intense.
Traditionally, laxatives have been classified according to general mechanism of
action. This scheme has four major categories:
(1) bulk-forming laxatives,
The bulk-forming laxatives (e.g., methylcellulose, psyllium, polycarbophil) have actions
and effects much like those of dietary fiber. These agents consist of natural or
semisynthetic polysaccharides and celluloses derived from grains and other plant
material. The bulk-forming agents belong to our therapeutic group III, producing a soft,
formed stool after 1 to 3 days of use.
• Mechanism of Action
Bulk-forming agents have the same effect on bowel function as dietary fiber. After
ingestion, these agents, which are nondigestible and nonabsorbable, swell in water
to form a viscous solution or gel, thereby softening the fecal mass and increasing
its bulk. Fecal volume may be further enlarged by growth of colonic bacteria, which
can utilize these materials as nutrients. Transit through the intestine is hastened
because swelling of the fecal mass stretches the intestinal wall and thereby
stimulates peristalsis.
• Indications
Bulk-forming laxatives are preferred agents for temporary treatment of
constipation. Also, they are widely used in patients with diverticulosis and irritable
bowel syndrome. In addition, by altering fecal consistency, they can provide
symptomatic relief of diarrhea and can reduce discomfort and inconvenience for
patients with an ileostomy or colostomy.
• Adverse Effects
Untoward effects are minimal. Because the bulk-forming agents are not absorbed,
systemic reactions are rare. Esophageal obstruction can occur if they are swallowed
in the absence of sufficient fluid. Accordingly, bulk-forming laxatives should be
administered with a full glass of water or juice. If their passage through the
intestine is impeded, they may produce intestinal obstruction or impaction.
Accordingly, they should be avoided if there is narrowing of the intestinal lumen.
• Preparations, Dosage, and Administration
Psyllium (prepared from Plantago seed), methylcellulose, and polycarbophil are the
principal bulk-forming laxatives. All three preparations should be administered with
a full glass of water or juice. (Dosages and trade names are shown in Table
63.4.)
(2) surfactant laxatives,
