Toxic Effects of Drugs
INTRODUCTION
 All drugs are potentially dangerous, even
though chemicals are carefully screened
and tested in animals and in people before
they are release as drugs.
 Drug products often cause unexpected or
unacceptable reaction when they are
administered.
 Drugs are chemical and the human body
operates by vast series of chemical reaction,
consequently many effects can be seen
when just one chemical factor is altered.
 Today’s potent and amazing drugs can
cause a great variety of reactions, many of
which are more severe than those you seen
before.
Paracelsus
(Grandfather of Toxicology)
“All substance are poisons; there is none which is
not poison. The right dose differentiate a poison
and a remedy”
 Flow of Slide Presentation
 Adverse Drug Reaction

Drug Allergy
Drug induced tissue and organ

damage





Adverse Drug Reaction
Expected Therapeutic Response:
 Drugs desired effect.
Adverse Drug Reaction (Side effect or
Adverse Effect)
Undesired effects to drug administration

that maybe unpleasant or even
dangerous. Harmful , undesirable
response.
 It can range from mild one that
disappear when the drug is discontinued
to debilitating diseases that become
chronic.
 It can appear shortly after starting a new
medication but may become less
severe with time.
 All drugs have adverse effects
associated with them.
 Adverse effects can be an extension of
the primary action or secondary effects
that are not necessarily desirable but are
unavoidable.
Reason for Adverse Effect
The drugs may have other effects on the
body besides therapeutic effect.
The patient may be sensitive to the drug
being given.
The drug’s action on the body may cause
other responses that are undesirable or
unpleasant.
 The patient maybe taking too much or too
little of the drug, leading to adverse effects.
Adverse Drug Reaction
Adverse effects can be one of the several types:
 Primary Action
 Secondary Action
 Hypersensitivity
 All drugs have effects other than the desired
therapeutic response.
 Primary action of the drug can be extension
of the desired effect.
 Secondary action of the drugs are effects
that the drug causes in the body that are not
related to the therapeutic effect.
 Hypersensitivity reaction to a drug are
individual reactions that maybe cause by
increased sensitivity to the drug’s therapeutic
or adverse effects.
Examples of Adverse Drug Reaction
 Primary Actions:
 Anticoagulant are medicines that help
prevent blood clots. They're given to people
at a high risk of getting clots, to reduce their
chances of developing serious conditions
such as strokes and heart attacks. A blood
clot is a seal created by the blood to stop
bleeding from wounds.
Example:
 An anticoagulant may act so effectively that
the patient experiences excessive and
spontaneous bleeding.
 This type of adverse effect can be avoided
by monitoring the patient carefully and
adjusting the prescribed dose to fit that
particular patient’s need.
 Antihypertensives are a class of drugs that
are used to treat hypertension (high blood
pressure)
 Example:
 A patient taking an antihypertensive drug
may become dizzy and weak, or faint when
taking the “recommended dose” but will be
able to adjust to the drug therapy with a
reduced dose.
 Secondary Action:
 Antihistamines reduce or block histamines, so
they stop allergy symptoms. These medicines
work well to relieve symptoms of different
types of allergies, including seasonal (hay
fever), indoor, and food allergies. But they
can't relieve every symptom. To treat nasal

congestion, your doctor may recommend a
decongestant.
Example:
Many antihistamines are very effective in

drying up secretion and helping breathing,
but they cause drowsiness.
 Nursing responsibility:
 Instruct patient not to drive a car or operate
power tool or machinery while taking
antihistamine because the drowsiness
could pose a serious problem.
 Hypersensitivity:
 Some patients are excessively sensitive to
either the primary or secondary effect of a
drug. It may result from pathological or
underlying condition.
Example:
 A patient who has kidney problem may not
be able to excrete the drug and may
accumulate the drug in the body, causing
toxic effects. The patient will exhibit
exaggerated adverse effects from standard
dose of medication because of the
accumulation of drugs .
DRUG ALLERGY




DRUG ALLERGY
Drug allergies occur when a patient
develops antibodies to a drug after exposure
to the drug.
A patient cannot be allergic to a drug that
has never been taken.
Assess patient understanding regarding drug
allergy. Ask additional question to verify
patient’s knowledge of drug allergy.
Four Main Classification of Drug Allergies
 Anaphylactic Reaction
 Cytotoxic Reaction
 Serum Sickness
 Delayed Reaction
Drug Induced Tissue and Organ Damage
 Drugs can act (directly and indirectly) to
cause many types of adverse effects in
various tissues, structures and organs.
 These effects occur frequently enough that
the nurse should be knowledgeable enough
about the presentation of the drug induced
damage about appropriate intervention to
be used should they occur.
 Dermatological Reaction

Rashes, Hives
Stomatitis

 Superinfection
Blood Dyscrasia
Toxicity
Liver injury
Renal injury
Poisoning
Tissue damage can include:
skin problem
mucous membrane inflammation
blood dyscrasia
Superinfection
liver or renal toxicity
poisoning
hypoglycemia or hyperglycemia,
electrolyte disturbances
various CNS problem (ocular damage,
auditory damage, atropine-like effects,
parkison’s-like syndrome, NMS)
teratogenicity

Dermatological Reaction
Meprobanate
Symptoms:
 Provide
(Anxiolytics)
 Hives and
frequent
rashes
skin care
It is important to
and other  Instruct
determine
dermatolo
the
whether a rash is
gical
patient to
a commonly
lesion
avoid
associated
maybe
rubbing ,
adverse effect of
seen.
wearing
the drug.
 Severe
tight or
reaction
rough
may
clothing,
include
using
exfoliative
harsh
dermatitis
soap or
characteri
perfumed
ze by rash
lotion.
and
 Administe
scaling
r
 Fever
antihista
 Enlarged
mine, as
nodes
appropria
 Enlarged
te.
liver
 In severe
 Potentially
cases,
fatal
discontin
erythema
ue the
multiform
drug .
e
 Topical
exudativu
corticoste
m (Steven
riods,
– Johnson
antihista
Syndrome
mine,
)
emolient.


















Antineoplasti
c can cause
Stomatitis.
Stomatitis –
inflammation
of mucous
membrane
Many drugs
are known to
cause
stomatitis.
Superinfection Infections
caused by
organism that
are usually
controlled by
the normal
flora.
Symptoms:
 Swollen
gums
 inflamed
gums,
swollen
and red
tongue.
(Glossitis)
 Other
symptoms
 difficulty
swallowin
g
 bad
breath
pain the
mouth
and
throat.
Superinfection
Symptoms :
ₒ
Fever
ₒ
Diarrhea
ₒ
black or
hairy
tongue
(glossitis)
ₒ
mucous
membrane
lesions
vaginal
ₒ
discharge
with or
without
itching.
Frequent
mouth
care
 frequent
small
meals
 If
necessary
, arrange
for dental
consultati
on.
NOTE :
Antifungal
agent and /or
local
anesthetics
are sometimes
used

ₒ




ₒ
ₒ
Blooddyscrasia is
bone marrow
suppression
caused by
drug effects.
ₒ
Occurs
when
drugs that
can cause
Blood Dyscrasia
Symptoms:
 Fever, chills, sore
throat,
weakness, back
pain, dark urine
 decrease
hematocrit
(anemia)
 low platelet
count(thrombo
Provide
supportive
measures
frequent
mouth
care
skin care
access to
bathroom
facilities
small
frequent
meals.
Antifungal
therapy as
appropriat
e.
Discontinue
the drug (in
severe
cases)
*Monitor
blood
counts
*Provide
supportive
measures
*Discontinu
e the drug
or Stop
administrat
cell death
are used.
DRUGS:
ₒ
Antineopl
astics
ₒ
Antibiotics


cytopenia)
low white blood
cell count
(leukopenia)
reduction of
cellular
elements of the
complete blood
count
(pancytopenia)
ion until
the bone
marrow
recovers
to a safe
level.
Toxicity
 Refers to the level of damage that a
compound can cause to an organism.
 These are not acceptable adverse effect but
are a potentially serious reaction to drugs.
 Known toxic effect- the benefits of the drug
must be weighed against the possibility of
toxic effect – harm to the patient .
Liver Injury (Hepatotoxicitity
Liver injury :
Symptoms :
 Discontinu
Metabolites that  Fever,
e the drug
are irritating or
 Malaise
 Offer
toxic will also
 Nausea
supportive
affect liver
 Vomiting
measures
integrity.
*Small frequent
 Jaundice
 change in meals
Hepatotoxic
color of
*Skin care
Drugs:
urine or
*Cool
*Acetaminophe
stools
environment
n
*Rest periods
 Abdomin
*Erythromycin
al pain or
*Iron overdose
colic
*Isoniazid
 Elevated
*Rifampicin
liver
*Sulfonamides
enzymes
 Alteration
in bilirubin
levels
 Changes
in clotting
factors.
Renal Injury (Nephrotoxicity)
Nephrotoxicity
Symptoms:
ₒ
Discontin
is define as
ₒ
Elevated
ue the drug
rapid
blood
ₒ
Offer
deterioration in
urea
supportive
the kidney
nitrogen
measure:
function due to ₒ
Elevated *Positioning
toxic effect of
creatinin *Diet and fluid
medications
e
restriction
and chemicals.
concent *Skin care
ration
*Electrolyte
Decreas
therapy
ₒ
Nephrotoxic
Drugs:
*Acetaminoph
en
*Acyclovir
*Aminoglycosid
es
*Amphotericin
B
*Ciprofloxacin
*Rifampicin
*Sulfonamides
*Tetracycline
*Contrast
medium
ₒ
ₒ
ₒ
ₒ
ₒ
ₒ
e
hemato
crit
Electroly
te
imbalan
ces
Fatigue
Malaise
Edema
Irritability
Skin rash
*Rest periods
*Controlled
environment
 Dialysis –
severe cases
Poisoning
 Poisoning occurs when an overdose of
drug damages multiple body system leading
to the potential for fatal reaction.
 Assessment parameters vary with the
particular drug.
 Treatment of drug poisoning also varies
depending on the drug.
Teratogenicity

Teratogenicity
Many drugs that reach the developing fetus

or embryo can cause death or congenital
(birth) defects which can include:
 Skeletal and limb abnormalities
 CNS alteration
 Heart defects
Teratogenic drugs
 Fluoroquinolones
 Aminoglycosides
 Tetracyclines
 ACE inhibitors
 Lithium
 Oral hypoglycemic agents
10 RIGHTS of Drug Administration
1. Right drug
2. Right patient
3. Right Dose
4. Right route
5. Right time and frequency
6. Right documentation
7. Right history and assessment
8. Drug approach right to refuse
9. Right drug- drug interaction and evaluation
10. Right education and information
Be Familiar with the Medication



The reason it is being administered.
Side effects and adverse effects.
Typical dose and range of safety, if
applicable.
Specific safety regulation before
administration.
 Check compatibility of medication with the
other drugs and infusion the patient is
receiving .
 Do not administer any medication that you
did not prepare.
Asses the Patient
 Food and drugs allergies.
e.g. eggs, milk, peanuts, fish, shellfish, wheat, soy,
penicillin, anticonvulsant, aspirin, ibuprofen and
chemotherapy drugs.
 Past medical history and present condition.
 Knowledge deficits and teaching needed.
Evaluate Responses
 Evaluate the patient for his or her response to
the medication, and document if
appropriate
 Report and unfavorable of unexpected
response.
Testing and Clinical Trials of Drugs
 Testing process begins with animal studies.
 Next step involves food and Drug
administration (FDA) to review the data
obtained in animal studies.
 Types of Clinical Trials
 Different types of clinical trials have specific
goals. For example:
 Treatment trials to test the effectiveness of a
new drug or procedure.
 Screening trials to test new ways of detecting
cancer or other health conditions in people
before they have any symptoms.

PHASES
PHASE-I
Treatment Trials
Trials are the first
step in testing a new
approach in people
trial tests an
experimental
treatment on a small
group of often
healthy people (20
to 80) to judge its
safety and side
effects and to find
the correct drug
dosage.
PHASE-II
PHASE-III
PHASE-IV
trial uses more
people (100 to 300).
While the emphasis
in Phase I is on
safety, the emphasis
in Phase II is on
effectiveness. This
phase aims to
obtain preliminary
data on whether
the drug works in
people who have a
certain disease or
condition. These
trials also continue
to study safety,
including short-term
side effects. This
phase can last
several years.
trial gathers more
information about
safety and
effectiveness,
studying different
populations and
different dosages,
using the drug in
combination with
other drugs. The
number of subjects
usually ranges from
several hundred to
about 3,000 people.
If the FDA agrees
that the trial results
are positive, it will
approve the
experimental drug
or device.
trial for drugs or
devices takes place
after the FDA
approves their use.
A device or drug's
effectiveness and
safety are
monitored in large,
diverse populations.
Sometimes, the side
effects of a drug
may not become
clear until more
people have taken
it over a longer
period of time.
Screening Trials
 The methods of detecting disease, often
called screening tests, can include:
 imaging tests that produce pictures of areas
inside the body.
 laboratory tests that check blood, urine, and
other body fluids and tissues.
 genetic tests that look for inherited genetic
markers linked to disease. A genetic marker is
a specific gene or other identifiable portion
of DNA that can be used to identify an
individual disease or trait.
Drug Concepts
 Generally, the client should not take antacid
with the medication or with milk because
antacid will affect the absorption of the drug.
 Enteric coated and sustained-release tablet
should not be crushed
 Capsules should not be opened
 Never adjust or change medication dose or
abruptly stop taking the medication without
consulting the physician or without Doctor’s
order.
 Generally, the client should not take antacid
with the medication or with milk because
antacid will affect the absorption of the drug.
Don’t rush to crush!
Enteric coated and sustained-release tablet

should not be crushed
Drug Concepts cont’d
 Avoid taking OTC any or any herbal.
preparation unless they are approved.
 Avoid smoking and drinking alcohol
beverages while taking specific drug.
 Never administer medication if the order is
difficult to read or dose that is not even within
the therapeutic range
Drugs That can Cause Staining
 Macrodantine
 Iron
 Lugol’s solution
 Tetracycline