1. PHARMACOLOGY - Introduction
DRUG ACTION:
Pharmaceutic,
Pharmacokinetic &
Pharmacodynamic Phases
A. Pharmaceutic Phase
- is the first phase of drug action
• The first phase of drug action
• Drug becomes a solution so that it can be
absorbed
2 Pharmaceutic phases: Disintegration &
Dissolution
Disintegration – is the breakdown of a
tablet/capsule into smaller particles
Dissolution – is the dissolving of the smaller
particles in the GI fluid before absorption
- Drugs in liquid form are more rapidly
available for GI absorption than are solids
- Enteric-coated drugs resist disintegration in
the gastric acid of the stomach, so
disintegration does not occur until the drug
reaches the alkaline environment of the
small intestine (enteric-coated tablets or
capsules and sustained release capsules
should not be crush, crushing would alter
the place and time of absorption of the drug
B. Pharmacokinetic Phase
• The of drug movement to achieve drug
action
The Process are: ABSORPTION, DISTRIBUTION,
METABOLISM (BIOTRANSFORMATION) &
EXCRETION
ABSORPTION
• Is the movement of drug particles from the
GI tract to body fluids by passive
absorption, active absorption, or Pinocytosis
• Most oral drugs are absorbed into the
surface area of the small instestine through
the action of extensive mucosal villi
• Passive absorption – occurs mostly by
diffusion (movement from higher
concentration to lower concentration)
• Active absorption – requires a carrier such
as enzyme or protein to move the drug
against a concentration agent (energy is
required for active absorption)
• Pinocytosis – is a process by which cells
carry a drug across their membrane by
engulfing the drug particles
FACTORS AFFECTING ABSORPTION
• BLOOD FLOW – poor circulation as a result
of shock, vasoconstrictor drugs, or disease
hampers absorption
• PAIN, STRESS & FOODS – slows gastric
emptying time, so the drug remains in the
stomach longer
• EXERCISE – decreases blood flow by
causing more blood to flow to the peripheral
muscle, thereby decreasing blood
circulation to the GI tract
• BLOOD SUPPLY– drugs given IM are
absorbed faster in muscles that have more
blood vessels (e.g. deltoids) than in those
that have fewer blood vessels (gluteals)
• FIRST PASS EFFECT – the process in
which the drug passes to the liver first,
metabolizing the drug to an active form
• BIOAVAILABILITY – is the percentage of
the administered drug dose that reaches the
systemic circulation (less than 100% for oral
route, 100% for IV route)
Factors Affecting Bioavailability:
a. The drug form (tablet, capsule, sustained
release, liquid, transdermal patch,
inhalation)
b. Route of administration
c. GI mucosa and motility
d. Food and other drugs
e. Changes in the liver metabolism caused by
liver dysfunction or inadequate hepatic
blood flow (a decrease in liver function or a
decrease in hepatic blood flow can increase
the bioavailability of a drug)
DISTRIBUTION
• The process by which the drug becomes
available to body fluids and body tissues
• Influenced by blood flow, drug’s affinity to
the tissue and the protein-binding effect
• Protein binding capability - Drugs that
binds to a carrier protein (albumin) is
pharmacologically becomes inactive
• Only “free drugs” (drugs not bound to
protein) are active and can cause
pharmacologic response
• Highly protein bound drugs - drugs that
are greater than 89% bound to protein e.g.
diazepam, digitoxin, furosemide, propanolol,
rifampin
• Moderately-Highly protein drugs – drugs
that are 61% to 89% bound to protein e.g.
erythromycin, quinidine, trimethoprim
• Moderately Protein bound drugs – drugs
that are 30-60% bound to protein e.g.
aspirin, lidocaine, meperidine, theophylline
• Low protein bound drugs – less than 30%
bound to protein e.g. amikacin,
amoxicillin,cephalexin, digoxin, terbutaline
sulfate, neostigmine bromide

2. Note: clients with liver or kidney disease or those
who are malnourished may have an abnormally low
serum albumin level (this results in fewer protein-
binding sites, which in turn leads to excess free
drug and eventually to drug toxicity)
METABOLISM
• Aka. “Biotransformation”
• The process by which a drugs are
inactivated by liver enzymes and are then
converted into inactive metabolites or water
soluble substances for Excretion
• The liver is the primary site of metabolism
• Decreased rate of drug metabolism
(cirrhosis/hepatitis) will cause excess drug
accumulation leading to drug toxicity
• HALF LIFE – is the time it takes for one half
of the drug concentration to be eliminated
Note: knowing the half-life, the time it takes for a
drug to reach a steady state of serum concentration
can be computed
e.g. Half-life of 650 mg of Aspirin
Time of
elimination
(hr)
Dosages
Remaining (mg)
Percentage
Left (%)
3 325 50
6 162 25
9 81 12.5
12 40 6.25
15 20 3.1
18 10 1.55
EXCRETION
• Refers to the elimination of drugs from the
body
• KIDNEY – is the main route of drug
elimination
• Other routes: hepatic metabolism, bile,
feces, lungs, saliva, sweat & breast milk
• Protein-bound drugs cannot be filtered
through the kidneys, once the drug is
released from the protein, it is a free drug
and is eventually excreted in the urine
Factors affecting Excretion
• Urine pH – urine pH ranging from 4.5 to 8.
Acid urine promotes elimination of weak
base drugs and alkaline urine promotes
elimination of weak acid drugs (aspirin)
• Kidney disease that results in decreased
glomerular filtration rate (GFR) or
decreased renal tubular secretion (drug
excretion is slowed or impaired)
• A decreased in blood flow to the kidneys
can alter drug excretion
Note: the most accurate test to determine renal
function is Creatinine Clearance. Creatinine is a
metabolic byproduct of muscle that is excreted by
the kidneys. Lower values are expected in elderly
and female clients because of their decreased
muscle mass. A decrease in renal GFR results in
an increase in serum creatinine level and a
decrease in urine creatinine clearance. (Normal
value is 85-135 ml/min)
C. Pharmacodynamic Phase
• Is the study of drug concentration and its
effects on the body
• Drug response can cause a primary or
secondary physiologic effect or both
• E.g. Diphenhydramine (Benadryl) –
antihistamine, primary effect is treat
symptoms of allergy, secondary effect –
CNS depression that causes drowsiness
ONSET, PEAK & DURATION of Action
• ONSET OF ACTION – is the time it takes to
reach the minimum effective concentration
after a drug is administered
• PEAK ACTION – occurs when the drug
reaches its highest blood or plasma
concentration
• DURATION OF ACTION – is the length of
time the drug has a pharmacologic effect
Receptor Theory
- Most receptors, protein in structure are
found on cell membranes
- Drugs act through receptors by binding to
the receptor to produce (initiate) a response
or to block (prevent) a response.
- The activity of many drugs is determined by
the ability of the drug to bind to a specific
receptor, “the better the drug fits at the
receptor site, the more biologically active
the drug is” (similar to lock and key concept)
AGONISTS & ANTAGONISTS
• AGONISTS – drugs that produce a
response
• ANTAGONISTS – drugs that block a
response
• E.g. Isoproterenol (Isuprel) simulates the
beta 1 receptor (agonist), Cimetidine
(Tagamet), an antagonist, blocks the
histamine (H2) receptor, thus preventing
excessive gastric acid secretion

3. THERAPEUTIC INDEX
• Therapeutic Index (TI) – estimates the
margin of safety of a drug through the use
of a ratio that measures the effective
(therapeutic) dose and lethal dose
• LOW THERAPEUTIC INDEX – have a
narrow margin of safety, drug levels need to
be monitored because of small safety range
• HIGH THERAPEUTIC INDEX – have a
wide margin of safety and less danger of
producing toxic effects, drugs do not need
to monitored routinely
Important Terms:
LOADING DOSE – a large initial dose to initiate
immediate drug response
SIDE EFFECTS – are physiologic effects not
related to desired drug effects
ADVERSE REACTIONS – are more severe than
side effects, undesirable effects of drugs that cause
mild to severe side effects
TOXIC EFFECTS or TOXICITY – drug level
exceeds the therapeutic range resulting from
overdosing or drug accumulation
TOLERANCE – refers to a decreased
responsiveness over the course of therapy
PLACEBO EFFECT – is a psychologic benefit from
a compound that may not have the chemical
structure of a drug effect
DRUG-DRUG INTERACTION – the effects of a
combination of drugs may be greater than, equal to,
or less than the effects of a single drug
FOOD-DRUG INTERACTION – the effects of
selected foods may speed, delay or prevent
absorption of specific drugs
PRINCIPLES OF DRUG ADMINISTRATION
- Administration of medications is a basic
activity in nursing practice
- Nurses must be knowledgeable about the
specific drugs and their administration,
client response, drug interactions, client
allergies
- Nurses are accountable for the safe
administration of medications
- Nurses must know all the components of a
drug order and questions those orders that
are not complete, unclear, outside the
recommended range,
- Nurses are legally liable if they give a
prescribed drug and the dosage is incorrect
or the drug is contraindicated for the client
The “Five-Plus-Five Rights” of Drug
Administration
• To provide safe drug administration, the
nurse should practice the “Rights” of drug
administration
1. RIGHT CLIENT
- Verify client by checking the identification
band
- Distinguish between two clients with the
same last name
2. RIGHT DRUG – means that the client receives
the drug that was prescribed
- A telephone order or verbal order for
medication must be cosigned by the
prescribing health care provider within 24
hours
Components of a Drug Order:
a. Date and time
b. Drug name
c. Drug dosage
d. Route of administration
e. Frequency and duration of
administration
f. Any special instructions
g. Physician or other health care provider’s
signature
Four (4) main categories of drug orders:
1. Standing – an ongoing order or may be
given for a specific number of doses or days
e.g. Digoxin 0.25 mg PO daily
2. One-time or Single orders – given once and
usually at a specific time e.g. Diazepam
5mg IV before surgery
3. PRN orders – given at the client’s request
and nurse’s judgment e.g. Tylenol 650mg
q3 to 4h PRN for headache
4. STAT orders – given once, immediately e.g.
Morphine sulfate 2mg IV STAT
3. RIGHT DOSE – is the dose prescribed for a
particular client
- Nurses must calculate each drug dose
accurately
- Before calculating a drug dose, the nurse
should have a general idea of the answer
based on knowledge of the basic formula or
ratios or proportions
4. RIGHT TIME – is the time at which the
prescribed dose should be administered
- Administer drugs at the specified times.
Drugs may be given 30 minutes before or
after the time prescribed if the
administration interval is >2hours
- Administer drugs that are affected by foods
before meals
- Administer drugs that can irritate the
stomach (gastric mucosa) with food
5. RIGHT ROUTE – is necessary for adequate or
appropriate absorption

4. - The more common routes are oral,
sublingual (under tongue for venous
absorption), buccal (between gum and
cheek), inhalation (aerosol sprays),
suppository (rectal, vaginal) & parenteral
(ID, SC, IM, IV)
- Assess the client’s ability to swallow before
the administration of oral medications
- Do not crush or mix medication in other
substances before consultation
- Use aseptic technique when administering
drugs. Sterile technique is required with the
parenteral routes
- Stay with the client until oral drugs have
been swallowed
6. RIGHT ASSESSMENT – requires that
appropriate data be collected before administration
of the drug e.g. taking apical HR before
administration of digitalis preparations or serum
blood sugar levels before the administration of
insulin
7. RIGHT DOCUMENTATION – requires that the
nurses immediately record the appropriate
information about the drug administered
This includes:
- Name of the drug
- Dose
- Route
- Time and date
- Nurse’s initials or signature
8. RIGHT TO EDUCATION – requires that clients
receive accurate and thorough information about
the medication and how it relates to their particular
situation including therapeutic purpose, possible
side effects, dietary restrictions
9. RIGHT EVALUATION – requires that the
effectiveness of the medication be determined by
the client’s response to the medication
10. RIGHT TO REFUSE – client can and do refuse
to take a medication, it is the nurse’s responsibility
to determine when possible the reason for the
refusal and to take reasonable measures to
facilitate the client’s taking the medication and
reinforce the reason for the medication
FORMS & ROUTES FOR DRUG
ADMINSTRATION
Tablets & Capsules
• Oral medications are not given to clients
who are vomiting, lack of a gag reflex or
who are comatose
• Administer irritating drugs with food to
decrease GI discomfort
• Administer drugs on empty stomach if food
interferes with medication absorption
• Drugs given sublingually or buccally remain
in place until fully absorbed, no fluids should
be taken while the medication is in place
Liquids
- Several forms of liquid medication including
elixirs (sweetened, hydroalcoholic liquid),
emusions (mixture of two liquids that are not
mutually soluble) and suspensions (particles
are mixed with but not dissolve in another
fluid)
- Read labels to determine whether dilution or
shaking is required
- The meniscus is at the line of the desired
dose
Transdermal
• Transdermal medication is stored in a patch
laced on the skin and absorbed through
skin, thereby having systemic effect
• Transdermal patches should be rotated to
different sites and not reapplied over the
next exact same area when changed
• The area should be thoroughly cleaned prior
to administration of a new transdermal
patch
Topical
• Topical medication can be applied to the
skin with glove, tongue blade or cotton-
tipped applicator
• Use appropriate technique to remove the
medication from the container and apply it
to the clean, dry skin
Instillations
Administration of Eye Drops
• Remove any discharge by gently wiping out
from inner canthus. Use separate cloth for
each eye
• Gently draw the skin down below the
affected eye to expose the conjunctival sac
• Administer the prescribed number of drops
into the center of the sac (not directly on the
cornea)
• Gently press on the lacrimal duct with sterile
cotton ball or tissue for 1-2 min. after
instillation to prevent systemic absorption
• Client should keep eyes closed for 1-2 min.
to promote absorption
Administration of Eardrops
• Medication should be at room temperature
• Client should sit up with head tilted slightly
toward the unaffected side

5. • CHILD: pull down and back on auricle.
AFTER 3 YEARS OF AGE/ADULT: pull up
and back on auricle
• Instill prescribed number of drops
• Have client maintain position for 2-3 min
Administration of Nose Drops & Sprays
- Have the client blow the nose
• Have the client tilt head back for drops to
reach frontal sinus and tilt head to affected
side to reach ethmoid sinus
• Have the client keep head tilted backward
for 5 minutes after instillation
Nasogastric and Gastrotomy Tubes
- Check for proper placement of tube
- Pour drug into syringe without plunger or
bulb, release clamp and allow medication to
flow in properly, usually by gravity
- Flush tubing with 50 ml of water
- Clamp the tube and remove syringe
SUPPOSITORIES
Rectal Suppositories
• Suppositories tend to soften at room
temperature and therefore need to be
refrigerated
• Use a glove for insertion
• Instruct the client to lie on left side and
breath through the mouth to relax the anal
sphincter
• Apply a small amount of water-soluble
lubricant to the tip and gently insert the
suppository beyond the internal sphincter
• Have the client remain lying on the side for
20 min after instillation
Vaginal Suppositories
• Generally inserted into the vagina with an
applicator
• Wear gloves
• The client should be in the lithotomy
position
PARENTERAL
Intradermal
• Local effect
• Used for observation of an inflammatory
(allergic) reaction to foreign proteins e.g.
tuberculin testing, testing for drug
sensitivities
• Site: lightly pigmented, hairless such as
ventral midforarm, clavicular area of the
chest & scapular area of the back
• Equipment: 25-27 gauge, 3/8 to 5/8 inches
in length, 1ml syringe
• Insert the needle bevel up, at a 10-15
degree angle
• Inject medication slowly to form a wheal
(bleb)
• Do not massage the area
• Assess for allergic reaction in 24 to 72
hours (measure the diameter of local
reaction)
Subcutaneous
• Systemic effect
• Sites: abdomen, upper hips, upper back,
lateral upper arms and lateral thighs
• Sites should be rotated with subcutaneous
injections i.e. Insulin & Heparin
• Equipment: 25-27 gauge, ½ to 5/8 inches in
length, 1-3 ml syringe (usually 0.5-1.5 ml is
injected)
• Insert the needle at an angle appropriate to
body size: 45 to 90 degrees
• Aspirate except heparin & Insulin
• Gently massage the area unless
contraindicated, as with heparin & Insulin
• Apply gentle pressure to the injection site to
prevent bleeding into the tissue
Intramuscular
• Systemic effect
• Usually more rapid effect of drug than with
SQ
• Sites: Ventrogluteal, Dorsogluteal, Deltoid
and Vastus Lateralis (pediatrics)
• Equipment: 20-23 gauge, 18 g for blood
transfusion, 1-1.5 inches in length
• Flatten the skin area using the thumb and
index finger and inject between them
• Insert the needle at 90 degree angle
• Ventrogluteal site – volume of drug
administration is 1-3ml (slightly angle the
needle toward the iliac crest)
• Dorsogluteal site - volume of drug
administration is 1-3ml, place the needle at
a 90 degree angle to the skin with the client
prone
• Deltoid site - volume of drug administration
is 0.5 to 1ml, place the needle at a 90
degree angle to the skin or slightly toward
acromion
• Vastus lateralis - volume of drug
administration is less than 0.5ml in infants, 1
ml in pediatrics, 1-1.5 ml in adults (direct the
needle at the knee at 45 to 60 degree angle
to the lateral middle thigh)
Z-Tract Injection technique
• Prevents the medication from leaking back
into the subQ tissue
• Used for medications that cause visible
permanent skin discolorations (e.g. iron
dextran)
• Gluteal site is preferred

6. STEPS:
• a. pull the skin to one side and hold
• b. insert needle
• c. Hold skin to side
• d. inject medication
Intravenous
• Systemic effect
• More rapid than the IM or subQ routes
• Site: accessible peripheral veins such as
cephalic vein of the arm, dorsal vein of hand
for direct IV
• Equipment: adults 20-21 gauge 1-1.5
inches, infants 24 gauge 1 inch

7. DRUGS FOR NEUROMUSCULAR DISORDERS:
Myasthenia Gravis, Muscle Spasm
Myasthenia Gravis (MG) – a lack of nerve
impulses and muscle responses at the myoneural
(nerve muscle endings) junction, causes fatigue
and muscular weakness of the respiratory system,
facial muscles and extremities, ptosis (early
symptoms), difficulty in chewing and swallowing
(dysphagia)
- Results from a lack of acetylcholine receptor
sites
- Group of drugs used to control MG is the
AChE inhibitors (aka. Cholinesterase
inhibitors & anticholinesterase) which
inhibits the action of enzyme and more
acetylcholine is available to activate the
cholinergic receptors and promote muscle
contraction
- Myasthenic crisis – severe generalized
muscle weakness and involve muscles of
respiration due to inadequate dosing of
AChE inhibitors
- Cholinergic crisis – an acute
exacerbations of symptoms of MG resulting
from overdosing with AChE inhibitors
manifested as severe muscle weakness that
can lead to respiratory paralysis
Acetylcholinesterase Inhibitors or
Cholinesterase Inhibitors
Prototypes:
- Neostigmine (Prostigmine) - first drug used
to manage MG, a short-acting
acetylcholinesterase inhibitor with a half-life
of 0.5 to 1 hour (given every 2-4 hours on
time to prevent muscle weakness)
- Pyridostigmine bromide (Mestinon) – has an
intermediate action and given every 3-6
hours
- Edrophonium CL (Tensilon) – for diagnosing
myasthenia gravis, ptosis should be absent
in 1-5 min. increase muscle strength for 5-
20 min.
Mode of action: transmission of neuromuscular
impulses by preventing destruction of acetylcholine,
increasing muscle strength
Side effects/ Adverse reaction: GI disturbances
(nausea/vomiting, diarrhea, abdominal cramps),
increased salivation and tearing
Underdosing – myasthenia crisis (muscle
weakness)
Overdosing – cholinergic crisis (severe muscle
weakness, dyspnea)
Nursing interventions (Acetylcholinesterase
Inhibitors)
1. Monitor effectiveness of drug therapy –
muscle strength should be increased
2. Observe client for signs and symptoms of
cholinergic crisis caused by overdosing i.e.
severe muscle weakness, increased
salivation, sweating, tearing
3. Have readily available antidote for
cholinergic crisis (atropine sulfate)
4. All doses of AChE inhibitors should be
administered ON TIME, because late
administration of the drug could result in
muscle weakness
SKELETAL MUSCLE RELAXANTS
- Muscle relaxants relieve muscular spasms
and pain associated with traumatic injuries
and spasticity
- Skeletal muscle Spasticity – is muscular
hyperactivity that causes contraction of the
muscles resulting in pain and limited
mobility
- Muscle spasms - have various causes
including injury or motor neuron disorders
that lead to conditions such as cerebral
palsy, spinal cord injuries, CVA which
causes pain and limited ROM mobility
Prototype:
Muscle Relaxants
1. Baclofen (Lioresal) – for muscle spasms
caused by multiple sclerosis and spinal cord
injury, overdose can cause CNS
depression, drowsiness, dizziness,
hypertension
2. Dantrolene sodium (Dantrium) – for chronic
neurologic disorders causing spasm i.e.
SCI, stroke, avoid taking with alcohol and
CNS depression
3. Pancronium bromide (Pavulon) – used in
surgery for relaxation of skeletal muscle
4. Succinylcholine CL (Anectine) – used in
surgery with anesthesia for skeletal muscle
relaxation
Side effects/Adverse Reactions:
Nausea, vomiting, dizziness, weakness, insomnia,
tachycardia, hypotension
Nursing Interventions (Muscle relaxants)
1. Monitor and report elevated liver enzymes
2. Observe for CNS side effects i.e. dizziness
3. Instruct client not to abruptly stop taking
muscle relaxant to avoid rebound spasms
4. Advise client not to drive or operate
dangerous machinery because of sedative
effect of drug i.e. drowsiness
5. Teach client to avoid alcohol and CNS
depressants
6. Contraindicated for pregnant mothers
ANTIDYSRHYTHMIC DRUGS

8. Cardiac Dysrhythmias (arrhythmia)
 Defined as any deviation from the normal
rate or pattern of the heartbeat, includes
heart rates that are too slow (bradycardia),
too fast (tachycardia) or irregular.
 The terms dysrhythmia (disturbed heart
rhythm) and arrhythmia (absence of heart
rhythm) are used interchangeably
 Frequently follow an MI or can result from
hypoxia, hypercapnia (increased CO2 in the
blood), coronary artery disease, excess
cathecolamines or electrolyte imbalance
 MOA: is to restore the cardiac rhythm to
normal
Classes and Actions of Antidysrhythmic drugs
CLASS I – Sodium Channel Blockers
1. Sodium Channel Blocker IA
 Slow conduction and prolong repolarization
 Indicated for atrial and ventricular
dysrhytmias, paroxysmal atrial tachychardia
Prototype:
Disopyramide phosphate (Norpace) – prevention
and suppression of unifocal and multifocal
premature ventricular contractions (PVC), may
cause anticholinergic symptoms
Procainamide HCL (Procanbid) – controls
dysrhythmias (PVC’s), ventricular tachycardia,
depresses myocardial excitability by slowing down
conductivity of cardiac tissue
Quinidine sulfate (Quinidex) – for atrial,
ventricular dysrhythmias. nausea, vomiting,
diarrhea, abdominal pain or cramps are common
discomfort
2. Sodium Channel Blocker IB
 Slow conduction and shorten repolarization
 Indicated for acute ventricular dysrhythmia
Prototype:
Lidocaine (xylocaine) – for acute ventricular
dysrhtymia following MI and cardiac surgery
Mexiletine HCL (Mexitil) – analogue of lidocaine.
Treatment for acute and chronic ventricular
dysrhytmias. Take with food to decrease GI
discomfort. Common side effects are
nausea/vomiting, heartburn, tremor, dizziness,
nervousness, lightheadedness
3. Sodium Channel Blocker IC
 Prolong conduction with little to no effect on
repolarozation
 Indicated for life-threatening ventricular
dysrhythmias
Prototype:
Flecainide (Tambocor) – for life-threatening
ventricular dysrhytmias, prevention of paroxysmal
supraventricular tachycardia (PSVT) and
paroxysmal atrial fibrillation or flutter (PAF),
contraindicated for cardiogenic shock and second
or third heart block
CLASS II - Beta Blockers
 Reduce calcium entry
 Decrease conduction velocity, automaticity
 Indicated for atrial flutter and fibrillation,
tachydysrhythmias, ventricular and
supraventricular dysrhythmias
Prototype:
Acebutol HCL (Sectral) –beta 1 blocker,
management of ventricular dysrhytmias. Also used
for angina pectoris and hypertension, primarily for
PVC’s, affects beta1 receptors (side effects:
bradycardia and decrease cardiac output)
Esmolol (Brevibloc) – beta 1 blocker, control atrial
flutter and fibrillation, short time used only, mainly
for clients having dysrhythmia during surgery
Propanolol HCL (Inderal) – beta 1 and beta 2
blocker, for ventricular dysrhythmias, PAT and atrial
and ventricular ectopic beats, contraindicated for
clients with asthma
CLASS III – Drugs that prolong Repolarization
 Prolong repolarization during ventricular
dysrhthmias
 Prolong action potential duration
 Indicated for life-threatening atrial and
ventricular dysrhythmias resistant to other
drugs
Prototype:
Adenosine (Adenocard) – treatment of PSVT.
Avoid if second or third degree AV block or atrial
flutter or fibrillation is present
Amiodarone HCL (Cordarone) – for life-
threatening ventricular dysrhytmias, initial dose and
greater then decrease over time
Bretylium tosylate (Bretylol) – for ventricular
tachycardia and fibrillation, used when lidocaine
and procainamide are ineffective
CLASS IV – Calcium Channel Blockers
 Block calcium influx, Slow conduction
velocity ,Decrease myocardial contractility
 Indicated for supraventricular
tachydysrhytmias, prevention of paroxysmal
supraventricular tachycardia (PSVT)
Prototype:
Verapamil HCL (Calan, Isoptin) – for
supraventricular tachydysrhythmias, prevention of
pSVT. Also used for angina pectoris and
hypertension, avoiduseif cardiogenic shock, second
or third degree AV block, severe hypotension occur
Diltiazem (Cardizem) – for PSVT and atrial flutter
or fibrillation, avoid use if second or third degree AV
block or hypotension occur
Nursing Interventions (Antidysrhythmics)

9. 1. Monitor ECG for abnormal patterns and
report findings i.e. premature ventricular
contractions
2. Instruct client to report side effect/adverse
reactions i.e. dizziness, faintness, nausea
and vomiting
3. Advise client to avoid alcohol and tobacco.
(Alcohol can intensify the hypotensive
reaction, caffeine increases the
cathecolamine level and tobacco promotes
vasoconstriction)
ADDITIONAL Miscellaneous Drugs:
LOW-MOLECULAR-WEIGHT HEPARINS (LMWH)
 An extract from the fraction of a standard
heparin with an equivalent anticoagulant
effect but lower risk for bleeding and
produces more stable responses at
recommended doses
 Derivatives of standard heparin introduced
to prevent venous thromboembolism
 Frequent laboratory monitoring of APTT is
not required because LMWH does not have
the standard of heparin
Prototype:
Dalteparin sodium (Fragmin) – for prevention of
DVT before surgey and for those at risk of
thromboembolism
Enoxaparin sodium (Lovenox) – for
thromboembolism. Prevents and treats DVT and
pulmonary embolism (bleeding is an adverse
reaction)
ANTIEMETICS
 Antivomiting agents
1. Dopamine Antagonists – suppress emesis
by blocking dopamine2 receptors in the CTZ
(chemotherapeutic trigger zone – lies near
the medulla and the vomiting center in the
medulla causes vomiting when stimulated)
- Common side effects: extrapyramidal
symptoms (EPS) – caused by blocking
dopamine receptors and hypotension
Prototype:
Phenothiazines
Prochlorperazine maleate (Compazine)
& promethazine (Phenergan)– for severe
nausea and vomiting (primary use), reduce
anxiety and tension (secondary use), side
effects: drowsiness, dizziness and dry
mouth
2. Metoclopramide HCL (Reglan) –
suppresses nausea &emesis (vomiting) by
blocking the dopamine receptors in the
CTZ, used in the treatment of postoperative
emesis, cancer chemotherapy and radiation
therapy (increases gastric and intestinal
emptying)
Bethanechol (Duvoid, Urecholine)
 Primarily act directly on muscarinic
acetylcholine receptors
 Facilitate contraction of detrusor muscle of
the urinary bladder
Indication
 Postoperative or postpartum urinary
retention
 Neurogenic atony of the bladder with
retention
LAXATIVES
 Used only after the client does not
adequately respond to other
nonpharmacologic interventions such as a
high fiber diet and increase fluids
Types
A. Stool Softeners or Surfactant Laxatives
 Mildest form of cathartic
 Detergent action lowers surface
tension, allowing water and fats to
enter and soften stool
 Used especially for clients who
should avoid straining
Prototype:
Docusate sodium (Colace)
Docusate calcium (Surfak)
Docusate with casanthranol (Peri-Colace) is
a stool softener combined with a stimulant
Adverse effects:Diarrhea and mild cramps
ANTIDIARRHEALS
 Inhibit peristaltic activity by direct action on
intestinal muscles
 Inhibit receptors responsible for peristalsis
Prototype:
 Kaolin and pectin (Kaopectate)
 Loperamide (Immodium)
 Diphenoxylate hydrochloride with atropine
sulfate (Lomotil)
 Paregoric (camphorated opium tincture)
 Bismuth subsalicylate (Pepto-Bismol)
Adverse effects:
 Nausea, vomiting, anorexia, abdominal
cramping, diarrhea, mild cramps
 Headache, dizziness, drowsiness
 Pruritus, rash
EMETICS
 Active ingredient is emetine which
stimulates the vomiting reflex located in the
medulla by stimulating the chemoreceptor
trigger zone and irritating gastric mucosa
1. Syrup of Ipecac
 used for accidental poisoning

10.  Currently being abused by clients
with bulimia nervosa
 Fatal dose is 10-25 mg
 Emetine is secreted slowly so a daily
dose of 30 ml is toxic and fatal after
several months
Recommended dose
 Children < 1 yr: 5-10 ml followed by ½ to 1
glass of water
 Children over 1 year old: 15 ml followed by
1-2 glasses of water
 Adults: 30 ml followed by 3-4 glasses of
water
 Vomiting generally occurs within 20 minutes
or dose may be repeated
Contraindications & precautions
 Unconscious client
 Pregnancy
 Lactation
 Poisoning from caustic substances such as
gasoline, kerosene
Nursing interventions
 Assess vital signs before administration
 Obtain ECG before administration
 Instruct to keep syrup of ipecac in a safe
locked location
 Avoid giving with milk products because
they delay the emesis
 Avoid giving with carbonated beverages
because they increase abdominal distention
2. Activated Charcoal
 Binds and inactivates the poison
until excreted
 Recommended to give as soon as
possible after ingestion of poisoning
but not within 1-2 hours of syrup of
ipecac
 Given as a powder prepared in an
aqueous slurry to absorb the poison
Recommended dose
 Children: not more than 1 dose
 Adults: 30-100 mg
Adverse effect
 Black tarry stools, diarrhea, constipation
Contraindications & precautions
 Unconscious client
 Pregnancy
 Lactation
 Poisoning from caustic substances such as
cyanide
Nursing interventions
 Avoid giving within 1-2 hours after ingestion
of syrup of ipecac
 Assess vital signs before administration
 May give with a laxative to promote
elimination
INSULIN, ANTIDIABETIC AGENTS &
GLUCAGON
 Insulin is produced by the beta cells in the
Islets of Langerhans in the pancreas
 Key role in the metabolism of CHO, CHOO,
CHON
 Glucagon is secreted by the alpha cells
from the Islets of Langerhans in the
pancreas and stimulates hepatic production
of glucose from glycogen stores
MOA of Insulin:
 Stimulates the active transport of glucose
into muscle and adipose tissue cells
 Regulates the rate at which carbohydrates
are burned by the cells for energy
 Promotes the conversion of glucose to
glycogen for storage in the liver
 Promotes the conversion of fatty acids into
fat which can be stored as adipose tissue
 Promotes conversion of amino acids to
proteins in muscle
 Promotes intracellular shifts of K and Mg
Indications
 Hormone replacement in the treatment of
DM type 1 and are unable to produce insulin
 Antidiabetic agents are used in the
treatment of DM type 2 and who produce an
insufficient amount of insulin
 Glucagon, a hyperglycemic agent, is used in
the acute management of severe
hypoglycemia when administration of
glucose is not feasible
Adverse reactions of insulin
 Hypoglycemia
 Coma
 Lipoatrophy and lipohypertrophy of the
injection site
 Local allergic reaction at the injection site
 Insulin resistance
 Allergic reaction
Nursing interventions
 Monitor blood glucose frequently when
therapy is initiated and routinely when
stabilized
 Monitor for hypoglycemia at peak time of
insulin e.g. apprehension, chills,
perspiration, confusion, double vision,
drowsiness, inability to concentrate,
shakiness, nausea, rapid pulse
 Monitor for hyperglycemia e.g. flushed skin,
acetone breath (fruity), polyuria, polydipsia
and anorexia
 Monitor weight at frequent intervals
 Use only insulin syringes which are
calibrated in units
 Before withdrawing the insulin, rotate the
vial between the palms of the hands to
ensure the medication is mixed into the
solution. Do not shake the vial.

11.  When mixing two insulins, draw up the
regular insulin first. This prevents
contamination of the regular insulin.
 Insulin should be kept in a cool place and
does not need refrigeration. Opened vials
should not be used after 30 days
 Regular insulin is the only insulin that can
be administered IV. The solution in the vial
should be clear and not cloudy.
 Regular insulin may be administered direct
IV undiluted or diluted in commonly used IV
solutions; however insulin potency may be
reduced by plastic or glass administration
systems
 Regular insulin my be administered up to 50
units in over 1 minute.
 Administer glucagon, epinephrine or IV
glucose 10-50% if the client is unresponsive
during hypoglycemia
 Instruct on injection sites: abdomen,
posterior arms, anterior thighs, hips),
rotation of sites to prevent lipodystrophy
 Rotation of sites should be 1.5 inches apart,
should be systematic and the site should
not be used again for a 2-3-week period
 Instruct that blood glucose should rise
approximately 5 minutes after the
administration of glucagon, if there is no
response in 20 min, seek emergency
assistance