3. INTRODUCTION
Drug – French word ‘Drogue’,
means dry herb.
Single active chemical entity in
medicine.
Various drugs and combination of
drugs used.
4. DEFINITIONS
PAIN – Unpleasant sensory and
emotional experience associated with
actual or potential tissue damage or
described in terms of such damage.
ANALGESICS – Drug that selectively
relieves pain by acting in CNS or on
peripheral pain mechanisms without
significantly altering consciousness.
14. Absorption, fate and excretion:
- Oral bioavailability ¼ of parenterally
administered drug
- Crosses placenta freely
- Primarily metabolised in liver
- Plasma t ½ – 2 to 3 hrs
- Effect of parenteral dose lasts 4-6 hrs
- Elimination is complete in 24hrs
- Noncumulative
15. Preparation and Dosage:
- Morphine solutions: 2-20 mg/ml for oral
use
- Morphine hydrochloride or sulfate inj.
Dose: 10-20 mg SC or IM ; 2.5-5 mg IV
slowly over 5 min.
- Controlled release tab. 10, 30, 60 mg of
morphine sulfate
16. ADVERSE REACTIONS
- Dysphoria, constipation, mental clouding,
vertigo, nausea and vomiting, headache,
fatigue, parasthesia, increased pressure in
biliary tracts.
- Intolerance
- Respiratory depression
- Hypotension
- Urinary retention
- On the foetus
- Tolerance
- Drug dependence
- Acute morphine poisoning
17. Therapeutic uses of morphine
- For relief of pain
- Sedation and sleep
- Preanaesthetic medication
- In acute left ventricular failure
- To produce constipation
Precautions & Contraindications
- Infants & elderly
- Respiratory insufficiency
- Head injury
- Hypothyroidism, liver & kidney disease
- Unstable personalities
18. CODEINE
Less potent analgesic than morphine.
Does not produce significant
depression of respiration
Low dependence liability
Enhances analgesic effect of aspirin
Better absorbed orally
Bioavailability is about 50%
Commonly used as an antitussive
Analgesic dose is 30-60 mg orally 3-4
times a day
21. NOSCAPINE
Anti-tussive action in therapeutic
doses
Potent releaser of histamine
Cause bronchospasm and
hypotension
Use in therapy of cough
22. HEROIN
Semisynthetic Derivative of Natural
Opium Alkaloid
Diacetylmorphine, Diamorphine
More powerful analgesic than morphine
Greater euphoria and has higher
dependence liability
Extensively used as a drug of abuse
23. APOMORPHINE
Stimulant of CTZ
Acts as potent emetic
Variety of behavioral,
neuropharmacological & endocrine
effects
Evaluate action of psychotropic
drugs
Adverse reactions – nausea,
vomiting, dizziness, hypotension &
bradycardia
25. Absorption, fate & excretion :
- Absorbed from gut
- Bioavailability of 50%
- Analgesic effect in 10-15 min
- Parenterally – action lasts for 2-4 hrs
- crosses placental barrier & secreted
in milk
- metabolised by liver
- small portion excreted unchanged in
urine
26. Preparations and Dosage:
- Pethidine hydrochloride tabs :
25-100 mg dose
- Pethidine hydrochloride inj. 2 ml
ampules-50 mg per ml of salt
- 25-100 mg im/sc
27. Adverse reactions:
- sweating, dysphoria, visual
disturbances, weakness & palpitation
- depression of foetal respiration
- bronchospasm & drying of
secretions
- respiratory depression, not suitable
in bronchial asthma
- overdosage causes respiratory
depression & coma, or tremors
myoclonus & convulsions
28. Tolerance & Dependence:
- Addict shows dilated pupils, tremors,
mental confusion, twitchings &
convulsions
- Dependence is common
- Withdrawal syndrome within 3 hrs
- Methadone is employed initially
30. NSAIDs
Block PG generation
PGs, PGI 2, TXA 2 produced from arachidonic
acid
Exists in constitutive(COX-1) &
inducible(COX-2) isoforms
COX-1 serves physiological housekeeping
functions
COX-2 induced by cytokines & other signal
molecules at site of inflammation
Most NSAIDs inhibit COX-1 & COX-2
nonselectively
Some selective COX-2 inhibitors produced
38. MEPHENAMIC ACID
Anthranilic acid derivative
Adverse effect: Diarrhoea, skin rashes,
dizziness & other CNS manifestation
Orally absorbed & t ½ is 2-4 hrs
Uses: Analgesic in muscle, joint & soft
tissue pain, dysmenorrhoea,
rheumatoid & osteoarthritis
Dose: 250-500 mg TDS
39. DICLOFENAC SODIUM
Aryl-acetic acid derivative
Well absorbed orally
Plasma t ½ - 2 hrs
Adverse effects: Epigastric pain,
nausea, headache, dizziness, rashes
Uses: Rheumatoid arthritis, ankylosing
spondylitis, dentistry, dysmenorrhea,
post traumatic & post inflammatory
conditions
Dose: 50mg TDS, then BD oral, 75mg
deep i.m
40. PIROXICAM
Oxicam derivative
Long acting potent NSAID
Good analgesic-antipyretic action
Metabolised in liver ; excreted in urine & bile
Plasma t ½ is 2 days
Side effects: heart burn, nausea & anorexia
Use as short term analgesic & long term
antiinflammatory drug – rheumatoid & osteo
arthritis, ankylosing spondylitis, acute gout,
musculoskeletal injuries, dentistry,
episiotomy,dysmenorrhoea etc
Dose: 20mg BD for 2 days followed by 20mg
OD
41. KETOROLAC
Pyrrolo-pyrrole derivative
Potent analgesic & modest antiinflammatory
Rapidly absorbed after oral & i.m
administration
Plasma t ½ is 5-7 hrs
Adverse effects: Nausea, abdominal pain,
dyspepsia, ulceration, loose stools,
drowsiness, headache, dizziness,
nervousness, pruritis, pain & fluid retention
Not be given to patients on anticoagulants
42. USES:
- Postoperative & acute
musculoskeletal pain: 15-30 mg i.m
or i.v every 4-6 hrs
- Used for renal colic, migraine, pain
due to bony metastasis
- Orally in a dose of 10-20 mg 6 hrly
43. NIMESULIDE
Preferential COX-2 inhibitors
Used for short lasting painful
inflammatory conditions like sports
injuries, sinusitis, ear nose throat
disorders, dental surgery, bursitis, low
backache, dysmenorrhoea, post
operative pain, osteoarthritis & for fever
Completely absorbed orally, excreted in
urine, t ½ of 2-5 hrs
44. Adverse effects:
- Epigastralgia, heart burn, nausea, loose
motions, rash pruritus, dizziness,
somnolence
- Hematuria & fulminant hepatic failure in
few cases
Useful in asthmatics, bronchospasm or
intolerance to aspirin & other NSAIDs
Dose: 100 mg BD
45. ROFECOXIB
Selective COX-2 inhibitors
Effective in osteoarthritis, rheumatoid
arthritis, dysmenorrhoea, dental, post
operative & acute musculoskeletal pain
at dose of 12.5-25 mg OD daily
Side effects are mild g.i complaints,
headache & dizziness
Well absorbed orally & t ½ of 17 hrs
Avoided in presence of severe hepatic
or renal disease
Dose: 12.5-25 mg OD
46. PARACETAMOL
Para-amino phenol derivative
Actions: Good & promptly acting
antipyretic
Well absorbed orally
Plasma t ½ is 2-3 hrs
Safe & well tolerated
Nausea & rashes occur occasionally
Analgesic nephropathy- years of heavy
ingestion
47. Acute paracetamol poisoning:
- In small children with glucuronide conjugating
ability
- Nausea, vomiting, abdominal pain, liver
tenderness
- Centrilobular hepatic necrosis accompanied by
renal tubular necrosis & hypoglycemia, may
progress to coma
- Jaundice after 2 days
- Treatment: Vomiting induced, activated
charcoal given, N-acetylcystein 150mg/kg
infused iv over 20hrs, alternatively, 75mg/kg
orally every 4-6 hrs for 2-3 days.
48. USES:
- First choice analgesic for osteoarthritis
- Best drug to be used as antipyretic
- Over the counter analgesic for headache,
musculoskeletal pain, dysmenorrhoea, etc
- Much safer than aspirin
- Does not prolong bleeding time
- Used in all age groups, pregnant & lactating
women, in other disease states & in patients in
whom aspirin is contraindicated
- No significant drug interactions
50. CONCLUSION
Nature of problem along with
consideration of risk factors in an
individual patient directs the initial
selection
Drugs differ quantitatively in
producing different side effects
Large inter individual differences
51. REFERENCES
Essentials of Medical Pharmacology,
K. D Tripathy, 5th edition
Pharmacology & Pharmacotherapeutics,
R. S. Satoskar,17th edition
