Effects of Drugs

The therapeutic effect of a drug, also referred

•Drug toxicity (harmful effects of a drug on an
to as the desired effect, is the primary effect
organism or tissue) results from overdosage,
intended, that is, the reason the drug is
ingestion of a drug intended for external use, or
prescribed.
buildup of the drug in the blood because of
impaired metabolism or excretion (cumulative
A side effect, or secondary effect, of a drug is
effect).
one that is unintended. Side effects are usually
predictable and may be either harmless or
• A drug allergy is an immunologic reaction to a
potentially harmful.
drug.

More severe side effects, also called adverse

• A severe allergic reaction usually occurs
effects or reactions, may justify the
immediately after the administration of the
discontinuation of a drug.
drug and is called an anaphylactic reaction.

Therapeutic Actions of Drugs Type of Medication Orders

• Palliative- Relieves the symptoms of a
disease but does not affect the disease A stat order indicates that the medication is to
itself. be given immediately and only once (e.g.,
• Curative- Cures a disease or condition. morphine sulfate 10 milligrams IV stat).
• Supportive- Supports body function
The single order or one-time order is for
until other treatments or the body's
medication to be given once at a specified time
response can take over.
(e.g., Seconal 100 milligrams at bedtime before
• Substitutive- Replaces body fluids or
surgery).
substances.
• Chemotherapeutic-Destroys malignant
The Standing order may or may not have a
cells.
termination date. A standing order may be
• Restorative- Returns the body to
carried out indefinitely (e.g., multiple vitamins
health.
daily) until an order is written to cancel it, or it
may be carried out for a specified number of
•Drug tolerance exists in a client who exhibits
days (e.g., KCI twice daily * 2 days).
an unusually low physiologic response to a drug
and who requires increases in the dosage to
A prn order, or as-needed order, permits the
maintain a given therapeutic effect.
nurse to give a medication when, in the nurse's
judgment, the client requires it (e.g., Amphojel
• A drug interaction occurs when the
15 mL prn). The nurse must use good judgment
administration of one drug before, at the same
about when the medication is needed and
time as, or after another drug alters the effect
when it can be safely administered.
of one or both drugs.
Essential Parts of a Drug Order Communicating a Medication Order
• Full name of the client • A drug order is written on the client's chart by
• Date and time the order is written a primary care provider or by a nurse receiving
• Name of the drug to be administered a telephone or verbal order from a primary care
• Dosage of the drug provider.
• Frequency of administration The nurse or clerk then copies the medication
• Route of administration order to a Kardex or medication administration
• Signature of the individual writing the record (MAR).
order

The nurse should always question the primary

care provider about any order that is
Parts of a Prescription
ambiguous, unusual (e.g., an abnormally high
• Descriptive information about the client:
dosage of a medication), or contraindicated by
name, address, and sometimes age
the client's condition. When the nurse judges a
primary care provider-ordered medication
• Date on which the prescription was inappropriate, the following actions are
written required:

• The Rx symbol, meaning "take thou o Contact the primary care provider and
discuss the rationale for believing the
• Medication name, dosage, and strength medication or dosage to be
inappropriate.
• Route of administration
o Document in notes the following: when
• Dispensing instructions for the the primary care provider was notified,
pharmacist, for example, "Dispense 30 what was conveyed to the primary care
capsules" provider, and how the primary care
provider responded.
• Directions for administration to be given
to the client, for example, "take on an o If the primary care provider cannot be
empty stomach" reached, document all attempts to
contact the primary care provider and
• Refill and special labeling, for example, the reason for withholding the
"Refill x 1” medication.

• Prescriber's signature o If someone else gives the medication,

document data about the client's
condition before and after the
medication.

o If an incident report is indicated, clearly

document factual information
Process of Administering Check Three Times for Safe
Medications Medication Administration

Identify the client. use at least two client FIRST CHECK

identifiers whenever administering medications • Read the MAR and remove the
Inform the client. the nurse should explain the medication(s) from the client's drawer.
intended action as well as any side effects or Verify that the client's name and room
adverse effects that might occur. Listen to the number match the MAR.
client. • Compare the label of the medication
Administer the drug. Read the MAR carefully against the MAR.
and perform three checks with the labeled • If the dosage does not match the MAR,
medications determine if you need to do a math
Provide assistive interventions as indicated. calculation.
Clients may need help when receiving • Check the expiration date of the
medications. medication.
Record the drug administered.
Evaluate the client's response to the drug. SECOND CHECK
While preparing the medication (e.g., pouring,
drawing up, or plac- ing unopened package in a
medication cup), look at the medication label
and check against the MAR.

THIRD CHECK
Recheck the label on the container (e.g., vial,
bottle, or unused unit- dose medications)
against the MAR before returning to its storage
place or before giving the medication to the
client.
Routes of Administration
Route Advantages Disadvantages
Oral Most convenient Inappropriate for clients with nausea or
Usually least expensive vomiting Drug may have unpleasant
Safe, does not break skin barrier taste or odor Inappropriate when GI
Administration usually does not cause tract has reduced motility Inappropriate
stress if client cannot swallow or is
Some new oral medications are designed unconscious
to rapidly Cannot be used before certain
dissolve on the tongue, allowing for faster diagnostic tests or surgical procedures
absorption and action Drug may discolor teeth, harm tooth
enamel
Drug may irritate gastric mucosa
Drug can be aspirated by seriously ill
clients
Same as for oral, plus: If swallowed, drug may be inactivated by
Sublingual Drug can be administered for local effect gastric juice Drug must remain under
More potent than oral route because drug tongue until dissolved and absorbed.
directly enters the blood and bypasses the May cause stinging or irritation of the
liver mucous membranes
Drug is rapidly absorbed into the
bloodstream Same as for sublingual

Buccal Same as for sublingual Same as for sublingual

Rectal Can be used when drug has objectionable Dose absorbed is unpredictable
taste or odor Drug released at slow, May be perceived as unpleasant by the
steady rate Provides a local therapeutic client Limited use
effect
Vaginal Provides a local effect May be messy and may soil clothes

Topical Few side effects Drug can enter body through abrasions
and cause
systemic effects
Leaves residue on the skin that may soil
clothes

Transdermal Prolonged systemic effect Rate of delivery may be variable

Few side effects Verify that the previous patch has been
Avoids Gl absorption problems removed and
Onset of drug action faster than oral disposed of appropriately to avoid
overdose

-to follow
Subcutaneous Absorption is slower (an advantage for Must involve sterile technique because
insulin and heparin administration breaks skin barrier More expensive than
oral
Can administer only small volume
Some drugs can irritate tissues and
cause pain
Can produce anxiety
Breaks skin barrier

Intramuscular Can administer larger volume than Can produce anxiety

subcutaneous Breaks skin barrier
Drug is rapidly absorbed

Absorption is slow (this is an advantage in Amount of drug administered must be

Intradermal testing for allergies) small Breaks skin barrier

Intravenous Rapid effect Limited to highly soluble drugs

Drug distribution inhibited by poor
circulation

Inhalation Introduces drug throughout respiratory Drug intended for localized effect can
tract have systemic effect
Rapid localized relief Of use only for the respiratory system
Drug can be administered to unconscious
client
Ten "Rights" of Medication • Know the agency's name alert
procedure when clients with the same
Administration
or similar last names are on the nursing
unit.
RIGHT MEDICATION
• The medication given was the
RIGHT CLIENT EDUCATION
medication ordered
• Explain information about the
medication to the client (eg, why
RIGHT DOSE
receiving what to expect, any
• The dose ordered is appropriate for the
precautions).
client.
• Give special attention if the calculation
RIGHT DOCUMENTATION
indicates multiple pills or tablets or a
• Document medication administration
large quantity of a liquid medication.
after giving it, not before.
This can be an indication that the math
• If time of administration differs from
calculation may be incorrect.
prescribed time, note the time on the
• Double-check calculations that appear
MAR and explain the reason and follow-
questionable.
through activities (e.g., pharmacy states
• Know the usual dosage range of the
medication will be available in 2 hours)
medication.
in nursing notes,
• Question a dose outside of the usual
• If a medication is not given, follow the
dosage range.
agency's policy for docu- menting the
reason why.
RIGHT TIME
• Give the medication at the night RIGHT TO REFUSE
frequency and at the time ordered
• Adult clients have the right to refuse
according to agency policy
any medication.
• Medications should be given within the
• The nurse's role is to ensure that the
agency guidelines.
client is fully informed of
• the potential consequences of refusal
RIGHT ROUTE
and to communicate the client's refusal
• Give the medication by the ordered
to the healthcare provider.
route.
• Make certain that the route is safe and RIGHT ASSESSMENT
appropriate for the client
• Some medications require specific
assessments prior to admin- istration
RIGHT CLIENT
(e.g., apical pulse, blood pressure,
• Medication is given to the intended laboratory results).
client.
• Medication orders may include specific
• Check the client's identification band parameters for admin- istration (e.g., do
with each administration of a not give if pulse less than 60 or systolic
medication. blood pressure less than 100).
RIGHT EVALUATION Administering parenteral drugs requires the
• Conduct appropriate follow-up (e.g., same nursing knowledge as for oral and topical
was the desired effect achieved or not? drugs; however, because injections are invasive
Did the client experience any side procedures, aseptic technique must be used to
effects or adverse reactions?). minimize the risk of infection.

Administering Oral Medications Syringes

• Goal: The patient will swallow the When handling a syringe, the nurse may touch
prescribed medication at the proper the outside of the barrel and the handle of the
time. plunger; however, the nurse must avoid letting
• Know the reason why the client is any unsterile object touch the tip or inside of
receiving the medication- the the barrel, the shaft of the plunger, or the shaft
classification, contraindications, usual or tip of the syringe.
dose range, side effects, and nursing
consideration for administering and
evaluating the intended outcomes for
the medications. Needles
Needles are made of stainless steel,
Assess: and most are disposable.
a. Allergies to the medication/s.
b. Client's ability to swallow.
c. Presence of vomiting or diarrhea. Needles used for injections have three variable
d. If the client is NPO or has gastric tubes. characteristics:
e. Has diminished or absent bowel sounds. 1. Slant or length of the bevel.
f. Client's knowledge of and learning needs 2. Length of the shaft.
about the medication. 3. Gauge (or diameter) of the shaft.
g. Perform appropriate assessments specific to
the medication.

Assemble equipment and supplies: Avoiding Puncture Injuries

• Medication tray, medication cups, pill crusher, • Use appropriate puncture-proof
medication administration record (MAR), disposal containers to dispose
drinking glass and water or juice. • of uncapped needles and sharps (Figure
35.25 These are provided in all client
areas. Never throw sharps in wastebas-
Parenteral Medications kets. Sharps include any items that can
• Nurses give parenteral medications: cut or puncture skin such as:
o intradermally (ID), • Needles
o subcutaneously, • Surgical blades
o intramuscularly (IM), or • Lancets
o intravenously (IV). • Razors
• Broken glass
 • Broken capillary pipettes
• Exposed dental wires
• Reusable Items (e.g. large-bore needles,
hooks, rasps, drill
• points)
• ANY SHARP INSTRUMENT!

•Never bend or break needles before disposal

•Never recap used needles (ie., ones that have

been inserted into clients) except under
specified circumstances

•transporting a syringe to the laboratory for an

arterial blood gas or blood culture).

• When recapping a needle (ie., drawing up a

medication into a syringe prior to
administration):

• Use a one-handed "scoop" method. This is

performed by (a) placing the needle cap and
syringe with needle horizon- tally on a flat
surface; (b) inserting the needle into the cap,
using one hand (Figure 35.26); and then (c)
using your other hand to pick up the cap and
tighten it to the needle hub, Be careful not to
contaminate the needle. If the needle becomes
contaminated, replace the needle with a new
one.