D3-Analgesics
By Caroline Bexfield and
Juan David Posada
D.3.1 Describe and Explain the different
ways which analgesics prevent pain.
 Pain: Is an unpleasant sensory associated with a
potential tissue damage which results from
interaction between various impulses arriving at
the spinal cord and the brain.
 When the tissues are injured they released
prostaglandins1 and leukotrienes2, which are
chemicals that causes the pain receptor to be
more sensitive. (Sensitized pain receptor react to
even gentle stimuli, causing pain).


1. A group of organic compounds derived from essential fatty acids and causing a
range of action including inflammation.
2. One of a group of hormones that cause the symptoms of hay fever. Derived from
arachidonic acid, the leukotrienes act by mediating immediate hypersensitivity.
Analgesics
Mild Analgesic
Used for relief of mild pain
Ex. Acetyl Salicylic Acid
(ASA) or also known as
Aspirins.
Metabolic
byproduct of phenacetin
(Acetaminophen) sold as
Tylenol or Paracetamol.
Phenacetin Ibuprofen sold
as Advil. Non-steroidal antiinflammatory
drugs
(NSAIDS).
This
mild
analgesics
are
non
addictive.
Strong Opiates
Used for relief of very
severe pain include the
narcotics morphine, heroin
(also
called
diacetylmorphine
or
diamorphine) and codeine.
These
are
controlled
substances
that
are
addictive.
.
Anesthetics
Local anesthetics
Are pain killers in
localized areas, includes
lidocaine and procaine
(used in dentistry.
General anesthetics
Act on the brain and
produce
reversible
unconsciousness as well
as insensitivity to pain.
How does Mild Analgesic
Work?
 They work by blocking the enzyme-controlled
synthesis of prostaglandins. Which prevents
many effects of the release of prostaglandin.
 The Constricting of the blood vessels.
 The increase of the permeability of capillaries.
Strong Analgesic (Opiates)
 How do they work?
 By temporarily binding to the opiate receptors
sites in the brain, preventing the transmission of
pain impulses without depressing the Central
Nervous System (CNS).
 Strong Analgesics simulates what the natural
painkillers that the body produces (endorphin
and encephalin) which are produce immediately
after an injury.
D.3.2
Describe the use of SA as a mild
analgesic and compare the advantages and
disadvantages of using Aspirin and Paracetamol
(acetaminophen).
Uses of the derivates of SA(salicylic acid)
 As a mild analgesic, is used to relieve minors
aches and pains, such as sunburns, headaches
and arthritis.
 As a anti-pyretic, is used to relieve fever.
Aspirin
 Advantages
 As an antiinflammatory (when
there is swelling from
injuries).
 As an anti-platelet agent
(in prevention for
abnormal blood
clotting).
 Disadvantages
 Can cause stomach
upset.
 Risks of gastrointestinal
bleeding.
 Allergic reaction.
 Is one of the most
frequent causes of
accidental poisoning in
infants.
Acetaminophen (Paracetamol)
 Advantages
 Disadvantages
 Does not upset the 
stomach.

 No possibilities of
internal bleeding.
Is not an effective antiinflammatory.
May have side effect such as
blood disorder or kidney
damage (vary rarely).
 Can not be taken by patients
with kidney or liver diseases.
 Over does may cause severe
damage to liver, brain
damage, coma or even death.
:)
D.3.3 Compare the
structures of Morphine,
Codeine and Heroin.
Chemical Structures
Heroin
QuickTime™ and a
decompressor
are needed to see this picture.
Codeine
QuickTime™ and a
decompressor
are needed to see this picture.
Morphine
Quic kTime™ and a
dec ompres sor
are needed to see this pic ture.
Strong Analgesics
 Advantages
 Disadvantages
 Relief of physical pain
 Major effect on the CNS, Eye
and gastrointestinal tract.
 Relief of emotional and  Produces drowsiness, mood
Psychological pain
changes and mental clouding.
 Induce a state of euphoria Loss of appetite; malnutrition,
 Reduced tension, worry
constipation.
and fear.
 Risk of dangerous infections
 Reduced coughing reflex. (AIDS, Hepatitis) due to
shared needles.
 Sterility
 Occasional Death from
overdose.