Ch 32 - Medication Administration.
Pharmacological Concepts: Medication Names:
Drugs can have up to three different names:
1. chemical
2. generic, and
3. trade
• Example of a well-known medication:
• Chemical: N-acetyl-para-aminophenol
• Generic: acetaminophen
• Trade: Tylenol, Panadol, Tempra
• Manufacturers choose trade names that are easy to pronounce, spell,
and remember.
• Many companies produce the same medication, and similarities in trade names
are often confusing.
• Therefore be careful to obtain the exact name and spelling for each medication
you administer to your patients.
Pharmacological Concepts: Drug Classifications:
Drugs are classified according to:
1. their characteristics
2. use in body systems, or
3. desired effects.
• Some medications can have more than one classification such as aspirin, which can
be analgesic, antipyretic, or anti-inflammatory.
• Medications come in several forms. [Table 32-1 Forms of Medication on text page 611]
Pharmacokinetics as the basis of medication:
Nurses need to :
1. use knowledge of pharmacokinetics when administering medications
2. selecting the route of administration
3. considering the patient’s risk for alterations in medication action, and
4. evaluating the patient’s response.
Four processes are included when considering pharmacokinetics:
1. absorption
2. distribution
3. metabolism, and
4. excretion.
For medications to be therapeutic, they must be:
1. taken into a patient’s body
2. be absorbed and distributed to cells, tissues, or a specific organ and
3. alter physiological functions.
,Ch 32 - Medication Administration.
Absorption:
• Each route of administration has a different rate of absorption.
Topical administration has the slowest rate of absorption, because of the physical makeup of the
skin.
• The mucous membrane and the respiratory tract have a quick rate of
absorption because these tissues contain many blood vessels.
• IV administration has the fastest absorption rate because these medications
are immediately available when they enter the systemic circulation.
If a doctor orders a STAT medication to be administered to patient then the best route of
administration is:
IV (Intravenous)
The oral route takes some time owing to the passage of medications through the GI tract
• When the site of administration contains a rich blood supply, the medication will
be absorbed quickly.
Safe medication administration requires:
1. knowledge of factors that alter or
2. impair absorption of prescribed medications.
Because some medications interact with food, it is often appropriate to administer them
1. before or after meals
2. with meals, or
3. on an empty stomach.
Additionally, when two medications are given together, they interfere with each other, which
then impairs absorption.
• Ensure that medications are given at the prescribed time for best absorption
• If medications interact with each other, ensure they are not given at the same time.
Distribution:
• The rate and extent of distribution depend on the physical and chemical properties
of the medication and the physiology of the patient.
• Once the medication has entered into the bloodstream, it is carried throughout
the tissues and organs of the body.
• The speed of distribution depends on the vascularity of various tissues and organs.
• Conditions that limit blood flow or blood perfusion inhibit the distribution of
a medication.
Membrane permeability refers to the ability of the medication to pass through tissue and
membranes to enter the target cell.
Some membranes serve as barriers to the passage of medications.
• For example, the blood-brain area allows fat-soluble medications to pass into the
brain and cerebrospinal fluid (CSF).
• Both fat-soluble and non–fat-soluble agents often cross the placenta and produce
fetal abnormalities such as respiratory depression.
,Ch 32 - Medication Administration.
• Some elderly patients experience adverse effects (confusion) as a result of the change
in permeability
• The degree to which medication binds to serum proteins will affect
medication distribution.
Metabolism:
• The liver is especially important because its specialized structure oxidizes and
transforms many toxic substances.
• The liver degrades many harmful chemicals before they are distributed to the tissues.
•
Biotransformation can also occur in the:
1. lungs
2. kidneys
3. blood, and
4. intestines.
Discuss.
If a decrease in liver function occurs such as with aging or liver disease, a medication usually is
eliminated more slowly, resulting in its accumulation.
Patients are at risk for medication toxicity if organs that metabolize medications are not
functioning correctly.]
Excretion:
1. What is the main organ for excretion?
• Kidneys (lungs liver, bowel and exocrine
glands 2. Which type of medications are excreted through the
lungs?
• Anesthetic gases, alcohol
3. Why should certain medications not be taken during pregnancy?
• Some may pass through the placental barrier or mammary glands.]- deep
breathing and coughing help patients’ eliminate these medications more
rapidly after surgery
The chemical makeup of a medication determines the organ of excretion
• The exocrine gland excrete lipid-soluble medications.
• When medications exit through sweat glands, the skin often becomes irritated,
requiring you to instruct patients in good hygiene practices.
• If a medication is excreted through the mammary glands, there is a risk that a
nursing infant will ingest the chemicals
• GI tract is another route of excretion:
•
• Medications that enter the hepatic circulation are broken down by the liver and
excreted into the bile.
• After chemicals enter the intestines through the biliary tract, the intestines resorb them.
, Ch 32 - Medication Administration.
• Factors that increase peristalsis (e.g., laxatives, enemas) accelerate medication
excretion through the feces,
• Whereas factors that slow peristalsis (e.g., inactivity, improper diet) often prolong
the effects of a medication.
• Some medications escape extensive metabolism and exit unchanged in the urine.
• Others undergo biotransformation in the liver before the kidneys excrete them.
• If renal function declines, a patient is at risk for medication toxicity. NTK: For the
older adult, a nurse must know how to assess for signs of medication toxicity within
older adults because of their Reduced glomerular filtration
When the kidney cannot adequately excrete a medication, it is necessary to reduce the dose.
Types of Medication Action:
Patients do not always respond in the same way to each successive dose of a medication.
• Sometimes the same medication causes very different responses in different patients.
• Therefore it is essential to understand all the effects that medications have on patients.
• Therapeutic effect: some medications have more than one therapeutic effect;
knowing the therapeutic effect helps with patient education and accurate evaluation
of desired effects
• Side effects are predictable, and often unavoidable secondary effects are produced at
a usual therapeutic dose.
• They may be harmless or may cause injury.
• If the side effects are serious enough to negate the beneficial effects of the
therapeutic action of the medication, the prescriber discontinues the medication.
• Patients often stop taking medications because of side effects.
• Some adverse effects, unintended, undesirable, & often unpredictable are
immediate, Toxic effects develop:
1. after prolonged intake of a medication, or
2. when a medication accumulates in the blood because of impaired metabolism or
excretion. Idiosyncratic reaction example: child takes benadryl, an antihistamine, & becomes
extremely agitated or excited instead of drowsy.
• In allergic reactions, the medication or chemical acts as an antigen, triggering the
release of antibodies in the body.
Severe or anaphylactic reactions, which are life threatening, are characterized by;
1. sudden constriction of bronchiolar muscles
2. edema of the pharynx and larynx, and
3. severe wheezing and shortness of breath.
4. Immediate medical attention is required to treat anaphylactic reactions.
[See also Table 32-2 on text p. 613 Mild Allergic Reactions.]
Urticaria-raised, irregularly shaped skin eruptions with varying sizes and shapes; have
reddened margins and pale centers
Rash-small raised vesicles that are usually reddened; often distributed over entire body
Pharmacological Concepts: Medication Names:
Drugs can have up to three different names:
1. chemical
2. generic, and
3. trade
• Example of a well-known medication:
• Chemical: N-acetyl-para-aminophenol
• Generic: acetaminophen
• Trade: Tylenol, Panadol, Tempra
• Manufacturers choose trade names that are easy to pronounce, spell,
and remember.
• Many companies produce the same medication, and similarities in trade names
are often confusing.
• Therefore be careful to obtain the exact name and spelling for each medication
you administer to your patients.
Pharmacological Concepts: Drug Classifications:
Drugs are classified according to:
1. their characteristics
2. use in body systems, or
3. desired effects.
• Some medications can have more than one classification such as aspirin, which can
be analgesic, antipyretic, or anti-inflammatory.
• Medications come in several forms. [Table 32-1 Forms of Medication on text page 611]
Pharmacokinetics as the basis of medication:
Nurses need to :
1. use knowledge of pharmacokinetics when administering medications
2. selecting the route of administration
3. considering the patient’s risk for alterations in medication action, and
4. evaluating the patient’s response.
Four processes are included when considering pharmacokinetics:
1. absorption
2. distribution
3. metabolism, and
4. excretion.
For medications to be therapeutic, they must be:
1. taken into a patient’s body
2. be absorbed and distributed to cells, tissues, or a specific organ and
3. alter physiological functions.
,Ch 32 - Medication Administration.
Absorption:
• Each route of administration has a different rate of absorption.
Topical administration has the slowest rate of absorption, because of the physical makeup of the
skin.
• The mucous membrane and the respiratory tract have a quick rate of
absorption because these tissues contain many blood vessels.
• IV administration has the fastest absorption rate because these medications
are immediately available when they enter the systemic circulation.
If a doctor orders a STAT medication to be administered to patient then the best route of
administration is:
IV (Intravenous)
The oral route takes some time owing to the passage of medications through the GI tract
• When the site of administration contains a rich blood supply, the medication will
be absorbed quickly.
Safe medication administration requires:
1. knowledge of factors that alter or
2. impair absorption of prescribed medications.
Because some medications interact with food, it is often appropriate to administer them
1. before or after meals
2. with meals, or
3. on an empty stomach.
Additionally, when two medications are given together, they interfere with each other, which
then impairs absorption.
• Ensure that medications are given at the prescribed time for best absorption
• If medications interact with each other, ensure they are not given at the same time.
Distribution:
• The rate and extent of distribution depend on the physical and chemical properties
of the medication and the physiology of the patient.
• Once the medication has entered into the bloodstream, it is carried throughout
the tissues and organs of the body.
• The speed of distribution depends on the vascularity of various tissues and organs.
• Conditions that limit blood flow or blood perfusion inhibit the distribution of
a medication.
Membrane permeability refers to the ability of the medication to pass through tissue and
membranes to enter the target cell.
Some membranes serve as barriers to the passage of medications.
• For example, the blood-brain area allows fat-soluble medications to pass into the
brain and cerebrospinal fluid (CSF).
• Both fat-soluble and non–fat-soluble agents often cross the placenta and produce
fetal abnormalities such as respiratory depression.
,Ch 32 - Medication Administration.
• Some elderly patients experience adverse effects (confusion) as a result of the change
in permeability
• The degree to which medication binds to serum proteins will affect
medication distribution.
Metabolism:
• The liver is especially important because its specialized structure oxidizes and
transforms many toxic substances.
• The liver degrades many harmful chemicals before they are distributed to the tissues.
•
Biotransformation can also occur in the:
1. lungs
2. kidneys
3. blood, and
4. intestines.
Discuss.
If a decrease in liver function occurs such as with aging or liver disease, a medication usually is
eliminated more slowly, resulting in its accumulation.
Patients are at risk for medication toxicity if organs that metabolize medications are not
functioning correctly.]
Excretion:
1. What is the main organ for excretion?
• Kidneys (lungs liver, bowel and exocrine
glands 2. Which type of medications are excreted through the
lungs?
• Anesthetic gases, alcohol
3. Why should certain medications not be taken during pregnancy?
• Some may pass through the placental barrier or mammary glands.]- deep
breathing and coughing help patients’ eliminate these medications more
rapidly after surgery
The chemical makeup of a medication determines the organ of excretion
• The exocrine gland excrete lipid-soluble medications.
• When medications exit through sweat glands, the skin often becomes irritated,
requiring you to instruct patients in good hygiene practices.
• If a medication is excreted through the mammary glands, there is a risk that a
nursing infant will ingest the chemicals
• GI tract is another route of excretion:
•
• Medications that enter the hepatic circulation are broken down by the liver and
excreted into the bile.
• After chemicals enter the intestines through the biliary tract, the intestines resorb them.
, Ch 32 - Medication Administration.
• Factors that increase peristalsis (e.g., laxatives, enemas) accelerate medication
excretion through the feces,
• Whereas factors that slow peristalsis (e.g., inactivity, improper diet) often prolong
the effects of a medication.
• Some medications escape extensive metabolism and exit unchanged in the urine.
• Others undergo biotransformation in the liver before the kidneys excrete them.
• If renal function declines, a patient is at risk for medication toxicity. NTK: For the
older adult, a nurse must know how to assess for signs of medication toxicity within
older adults because of their Reduced glomerular filtration
When the kidney cannot adequately excrete a medication, it is necessary to reduce the dose.
Types of Medication Action:
Patients do not always respond in the same way to each successive dose of a medication.
• Sometimes the same medication causes very different responses in different patients.
• Therefore it is essential to understand all the effects that medications have on patients.
• Therapeutic effect: some medications have more than one therapeutic effect;
knowing the therapeutic effect helps with patient education and accurate evaluation
of desired effects
• Side effects are predictable, and often unavoidable secondary effects are produced at
a usual therapeutic dose.
• They may be harmless or may cause injury.
• If the side effects are serious enough to negate the beneficial effects of the
therapeutic action of the medication, the prescriber discontinues the medication.
• Patients often stop taking medications because of side effects.
• Some adverse effects, unintended, undesirable, & often unpredictable are
immediate, Toxic effects develop:
1. after prolonged intake of a medication, or
2. when a medication accumulates in the blood because of impaired metabolism or
excretion. Idiosyncratic reaction example: child takes benadryl, an antihistamine, & becomes
extremely agitated or excited instead of drowsy.
• In allergic reactions, the medication or chemical acts as an antigen, triggering the
release of antibodies in the body.
Severe or anaphylactic reactions, which are life threatening, are characterized by;
1. sudden constriction of bronchiolar muscles
2. edema of the pharynx and larynx, and
3. severe wheezing and shortness of breath.
4. Immediate medical attention is required to treat anaphylactic reactions.
[See also Table 32-2 on text p. 613 Mild Allergic Reactions.]
Urticaria-raised, irregularly shaped skin eruptions with varying sizes and shapes; have
reddened margins and pale centers
Rash-small raised vesicles that are usually reddened; often distributed over entire body
