ANALGESICS
DR MOHAMMED MALIK AFROZ
SPECIFIC LEARNING OBJECTIVE
 TO KNOW THE WORKING CLASSIFICATION OF
ANALGESICS
 TO KNOW THE DIFFERENT ANALGESICS AND ITS
ACTION
 TO KNOW THE ADVERSE EFFECT OF THESE
ANALGESICS
FORMAT
 DEFINITION AND CLASSIFICATION OF ANALGESICS
 WORKING MECHANISM OF DIFFERENT ANALGESICS
 ADVERSE EFFECTS OF THESE ANALGESICS
INTRODUCTION
 ALGESIA ( PAIN):
IT IS AN ILLDEFINED, UNPLEASANT
SENSATION, USUALLY EVOKED BY AN EXTERNAL
OR INTERNAL NOXIOUS STIMULUS.
ANALGESIC:
A DRUG THAT DIRECTIVELY RELIVEVES PAIN
BY ACTING IN THE CNS OR ON PERIPHERAL PAIN
MECHANISMS WITHOUT SIGNIFICANTLY ALTERING
CONSCIOUNESS.
TYPES OF ANALGESICS
A. OPIOID NARCOTIC/MORPHINE LIKE
ANALGESICS
B. NON-OPIOID/NON-NARCOTIC/ASPRINLIKE/ ANTI-PYRETIC OR ANTIINFLAMMATORY ANALGESICS
CLASSIFICATION OF NSAID – NON
STEROIDAL ANTI INFLAMMATORY DRUGS
A. Analgesic and anti – Inflammatory
1.Salicylates
:
Aspirin, Salicylamide,
Benorylate,
Diflunisal.
Phenylbutazone,
2.Pyrazolone derivatives:
Oxyphenbutazone.
3.Indole derivatives
:
Indomethacin, Sulindac.
4.Propionic acid derivatives: Ibuprofen, Naproxen,
Ketoprofen, Fenoprofen,
Flurbiprofen.
5.Anthranilic acid derivative: Mephenamic acid.
6.Aryl-acetic acid derivatives: Diclofenac, Tolmetin
7.Oxicam derivatives:
8.pyrrole derivative
Piroxicam, Tenoxicam,Meloxicam.
:
Ketorolac.
9.Sulfonailide derivative : Nimesulide
10.Alkanones :
Nabumetone
WORKING PRINCIPLE of NSAIDS

Most NSAIDS block cyclo – oxygenase enzymes involved
in prostaglandin synthesis which exists in two forms:
 COX-1 and COX-2
 During inflammation , pain ,fever, arachidonic acid is
liberated from phospholipids fraction of the cell
membrane, arachidonic acid is then enzymatically
(CYCLO – OXYGENASE ENZYME) converted to
prostaglandin(PGI2) and thromboxane A2 in presence
of enzyme cyclooxygenase
B.Analgesic poor but good anti – Inflammatory
1.Para – aminophenol derivative :
Paracetamole (Acetaminophen)
2.Pyrazolone derivatives :
Metamizol (Dipyrone), Propiphenazone.
3.Benzoxazocine Derivative : Nefopam
SALICYLATES
 Salicylates are esters or salts of salicylic acid
Pharmacological actions of salicylates:
 1)
C.N.S. produce relief of pain without hypnosis or
impairment of mental activity. Used for relief of dull
aching, throbbing pain of low intensity coming from
integument structures such as muscle and joints, also
relieves tooth ache. (Action by acting at thalamic and
hypothalamic sites) C.N.S.
 Antipyretic action : In fever the thermostatic mechanism is set at a
higher level and salicylates act centrally to reset this mechanism at
the normal level. (It acts by inhibition of brain prostaglandin
synthesis).
 GIT produces epigastric distress, nausea, vomiting due to stimulation
of C.T.Z. and irritation of gastric mucous membrane.
 Can cause dyspepsia, erosive gastritis, frank peptic ulceration and
gastrointestinal haemorrhage leading to hematemesis or melena.

Hence administer after food.
 C.V.S: in therapeutic does no adverse effect & in higher doses
paralysis of vasomotor center.
 Adverse reactions :
 1)
Allergic reaction: skin rash, urticaria, pruritus
angioneuurotic edema, bronchial asthma, anaphylactic shock and
thrombo cytopenic purpura.
 2)
 3)
G.I.T :dyspepsia, nausea, vomiting, heart burn.
Haemopoietic system: in large doses reduces plasma
prothrombin level
 4)
Liver and kidney :may cause fatty infiltration and acute
renal failure
 5)
Pregnancy lactation :delays onset of labour ,and may
cause greater blood loss at delivery. pulmonary hypertension in
new born.
 6)
Salicylism : prolonged administration of salicylates
may cause a condition of mild salicylate intoxication, head
ache dizziness, vertigo, tinnitus, difficulty in hearing
dimness of vision, drowsiness, lethargy mental confusions,
vomiting ,diahorrea.
Reye's syndrome :
 In children under 12years when treated with aspirin for
chicken pox or influenza suffered from Reye's syndrome.
Preparation and dosage :
1.Aspirin tablets - 300 mg or 350mg tabs.
2.Injectable preparation
(lysine acetylsalicylate 450mg + glycine 50mg/vial
for dissolving in 5ml water and i.v injection)
Precautions and contraindications:
 Allergic
 Peptic ulcer
 Bleeding tendencies
 Chronic liver diseases
 Children suffering from chicken pox or influenza
 Pregnant women-low birth weight babies.
Therapeutic
uses :
 1.Local action – keratolytic, Fungistatic.
 2.Analgesic
 3.Antipyretic.
 4.Anti inflammatory.
 5.Acute rheumatic fever
 6.Rheumatoid arthritis
 7.Osteoarthritis
 8.Postmyocardial infarction and post stroke
patients
PHENYLACTIC ACID DERIVATIVES
DICLOFENAC SODIUM:
 Analgesic ,antiinflammatory and antipyretic drug
 Inhibits PG synthesis and short lasting antiplatelet action
 Its concentration in synovial fluid is three times more than
in plasma.
 PREPATATION:-
 Dosage:60mgbid/tid.i.m-75mg 1-2 times/day.
Diclofen,dicloran,diclomol,inac,oxalgin,
Indications:
 Osteoarthritis, rheumatoid arthritis, ankylosing
spondylitis ,bursitis
 Dysmenorrhoea,
 Post traumatic and postoperative inflammatory
conditions
Adverse effects:
 Epigastric pain ,nausea, dizziness, headache,
rashes
 Aplastic anemia
PROPIONIC ACID DERIVATIVES
IBUPROFEN, NAPROXEN, FENOPROFEN,
FLURBIPRCFEN, KETOPROFEN:Have analgesic ,anti pyretic and anti inflammatory
properties similar to aspirin but are better tolerated
orally although they may produce gastric irritation
and ulceration.
 They are highly bound to plasma protein 90-99%
 As they inhibit platelet function should be avoided with
anticoagulants
 Better tolerated then aspirin
 Not to be prescribed in pregnant women and peptic ulcer
patient
Uses:-patients with Rheumatoid arthritis,
ankylosing
spondylitis who cannot tolerate aspirin.
 Soft tissue injuries fractures ,vasectomy, tooth extraction,
post partum and post operatively
 It is available as an `Over The Counter Drug’
 Adverse effects:-
Gastric discomfort, nausea, vomting-common.
2. Gastric erosion, occult blood loss- rare.
3. CNS:- headache, dizziness, blurring of vision, tinnitus &
depression.
4. Rashes, itching& other hypersensitivity reactions.
 Contraindications: Avoided to pregnant women, peptic ulcer patients.
1.
 DOSAGE:1.2-1.8 g/day .
BRUFEN,IBUGESIC,IBUGIN.
IBUBROFEN(400mg)+PARACETMOL(325 mg)
 ANAFLAM,BRUCET,CALPOL,FLEXON,COBIFLAM,
MAGADOL.
ANTHRALIC ACID DERIVATIVES
 MEFENAMIC ACID : It is an anthralic acid derivative
 Useful in chronic dull aching pain. It is a weaker analgesic
than aspirin.
 Toxic reaction include gastric upset, diarrhoea, dizziness,
head ache, skin rashes, haemolytic anemia and blood
dyscrasias.
 It exerts peripheral as well as central analgesic action
 Indicated primarily as analgesic in muscle joint and soft tissue
pain
 250-500mg TID
PYROLO PYRROLE DERIVATIVE
KETOROLAC.
 Highly potent member of a new class of analgesic
compound. Both anti – Inflammatory and analgesic but
more systemic analgesic than anti inflammatory, potent
than indo – methacin, naproxen, phenyl – butazone.
.
Dosage:30-60mg IM.
Oral- 20mg initially then 10mg 4-6 hrs.
ketonov, ketorol dt.

Adverse effects:-nausea, abdominal pain, dyspepsia,
ulceration, loose stools, drowsiness, headache, dizziness,
nervousness, pruritis, rise in serum transaminase.
Contraindications: Should not be given to patients on anticoagulants.
Uses: 1)post operative pain, acute musculoskeletal pain-15 -30 mg
i.m. or i.v. for every 4 to 6 hours.
 2) renal colic, migraine, pain due to metastasis.
SULFONANILIDE DERIVATIVE
Nimesulide:
Newer NSAID is a relatively weak inhibitor of PG
synthesis (selective for COX-2 )
Used primarily for short lasting painful
inflammatory conditions like sports injuries ,
sinusitis and other ear ,nose ,throat disorders, dental
surgeries , bursitis, low backache ,dysmenorrhoea,
postoperative pain and osteoarthritis .
It can be given in asthmatics.
CONTRAINDICATIONS:gi bleed, peptic ulcer, hepatic
dysfunction, pregnancy, lactation.
 ADVERSE EFFECTS: epigastralgia,
heart burn, nausea,
loose motions.
Dermotological:-rash, pruritis.
CNS:- somnolence, dizziness.
Renal:-hematuria,
Liver:- hepatic failure.
 Dosage : 100 mg BD, Completely absorbed orally
,metabolized and excreted in urine.
VALDECOXIB
Indications :
Signs and symptoms of osteoarthritis and adult
rheumatoid arthritis
Pain associated with dysmenorrhoea
Post surgical analgesia
Mechanism of action:
Selective COX-2 inhibitor
Dosage and administration :
 In osteoarthritis and rheumatoid arthritis
 (10mg once daily)
 Pain associated with primary dysmenorrhoea
 20mg twice daily as needed
 Peak plasma concentration: 161.1
 Adverse effects:
 Increase incidence of nausea in some trials
ROFECOXIB
Indications:
 For relief of signs and symptoms of osteoarthritis
 For management of acute pain in adults
 For treatment of primary dysmenorrhoea
 for relief of postorthopedic surgery pains
Pharmacokinetic profile:
 Rofecoxib is moderately 87% bound to plasma proteins
 The half life is approximately 17 hours ,allowing for once daily
dosing
 Available as 50mg, 25mg, 12.5mg and bottle of 60ml
suspension
 Administered orally
 Eliminated by hepatic metabolism, with less than 1% recovered
unchanged in urine
 Mechanism of action:
 Inhibition of prostaglandin synthesis, primarily
via inhibition of cyclooxygenase-2 (COX-2)
isoenzyme,
 Rofecoxib is 800 times more selective for COX-2
relative to COX-1

Adverse effects:
 Diarrhoea
 Headache
 Insomnia
 Edema
 Nausea
 Upper respiratory tract infections
 Osteoarthritis :
 The recommended starting dose of rofecoxib is 12.5 mg once daily.
The maximum daily dose is 25mg
 Management of acute pain and treatment of dysmenorrhea
 The recommended oral dose is 50mg once daily for a maximum of 5
days
 USE IN CHILDREN
 Safety and effectiveness in pediatric patients below the age
of 18yrs have not been evaluated
 USE IN PREGNANT WOMEN
 Rofecoxib should only be used in pregnant women only
when the benefit clearly outweighs the potential risk
 In late pregnancy it should be avoided because it may cause
premature closure of the ductus arteriosus
 It should be avoided in nursing women
COMBINATION NSAID-OPIATE ANALGESIC
MEDICATIONS
 TYLENOL(acetaeminophen 300mg + codeine 30mg)
 INDICATIONS: moderate to severe pain
 CONTRAINDICATIONS: allergy, renal or liver impairment
 SIDE EFFECTS: nausea, abdominal pain, head ache, dizziness,
rash, constipation, fluid retention, peripheral edema.
 EMPIRIN(aspirin 325mg + codeine 30mg) – moderate
to severe pain
 COMBUNOX(ibuprofen 400mg + oxycodone 5mg) –
moderate to severe pain.
 VICODIN, LORCET, LORTAB(hydrocodone 5mg +
acetoaminophen 500mg)
USE OF ANALGESIA IN PREGNANCY AND LACTATION:
NSAIDS may predispose to ineffective contractions
during labour, increased bleeding during delivery or
premature closure of the ductus arteriosus of the
heart. NSAIDS are therefore contraindicated in the
third trimester
.
USE OF ANALGESIC FOR ELDERLY PATIENTS:
Acetaminophen is the analgesic of choice in the
elderly
NSAIDS are a major concern due to the potential
for GIT bleeding ,which become more likely with
increasing age ,if there is history of gastric
bleeding and if high doses of NSAIDS or multiple
NSAIDS are used.
Thank you