Role of analgesics in Exodontics

Dr. V.RAMKUMAR

CONSULTANT DENTAL AND FACIOMAXILLARY SURGEON

REG NO: 4118 TAMILNADU – INDIA ( ASIA)

Analgesics are drugs that selectively relieve pain by acting on the CNS or on the peripheral pain mechanisms without significantly altering consciousness.

Classification of analgesics

1…Opiod/Narcotic or morphine like Natural (opium) Semisynthetic opioids Synthetec opiods Agonist/Antagonist

2…Non opioid/Non steroidal anti-inflammatory analgesics and antipyretics

Potent anti inflammatory and good analgesics Potent anti inflammatory and poor or

moderate analgesics Moderate anti inflammatory and moderate

analgesecs Poor anti inflammatory and good analgesic

Opioid analgesics

1. MORPHINE

Morphine acts by – Raising pain threshold assisted by euphoria

which it produces Modifies emotional reaction to pain Induces sleep

it is best avoided in asthmatics.

Adverse effects – Nausea Vomiting Respiratory depression Histamine release Broncho constriction Postural hypotension Constipation Tolerance and dependence

Preparation and dose – Morphine sulphate 10 mg/ml for i.m. use. Preservative free solutions 1 mg/ml are

intended for I.V. use.

2. CODEINE (Sulphate or phosphate)

30 mgs of codeine is equianalgesic with 600 mgs of aspirin and has a synergistic effect with aspirin.

No respiratory depression, no pupillary effects and less chance of addiction.

Used along with aspirin as an analgesic.

3. PETHIDINE (Meperidine)

1/10th as potent as morphine as an analgesic.

Adverse effects – Respiratory depression Produce mydriasis Nausea Vomiting Hypotension following pethidine

Dose – 50 to 100 mgs i.m. or i.v.Uses – in severe pain and as a premedication before

anesthesia

4. DEXTROPROPOXYPHENE

As an analgesic, half as potent as codeine.With aspirin gives a better analgesic effect.

Adverse effects – Nausea Constipation Drowsiness

Dose – 65 mgs of dextropropoxyphene with 40 mgs aspirin

5. PENTAZOCINE (Fortwin 30 mg/ml or 25 mg tablets)

30 mgs of pentazocine produces analgesia produced by 10 mgs of morphine.

Respiratory depression 1/3 as that produced by morphine.

Contraindicated in myocardial infarction and coronary ischemia.

Adverse effects – Sedation Nausea Sweating and dizziness or light headedness.

Dose- 25 to 100 mgs oral30 to 60 mgs IM or IV

Non opioid analgesics

1.ASPIRIN

Act as an antipyretic and also produces cutaneous vasodialatation.

As an analgesic, weaker than morphine type drugs

Best analgesic in a diabetic when carefully used.

Best avoided in patients with bleeding tendencies

Should not be given to patient on dicoumerol. Can cause hypoglycemia.

Adverse effects – Hypersensitivity Nausea Vomiting Epigastric distress GL bleeding

ASPIRIN tablets

Microfine particles 300mgs

or soluble aspirin For pain upto 120 mgs daily

with calcium carbonate For rheumatic fever

and citric acid 4 to 8 gram daily

Preparation and dose –

2. PHENACETIN AND PARACETAMOL

Central analgesic action similar to aspirin Weak peripheral anti inflammatory effect and Poor inhibitors of prostaglandin synthesis

Adverse effects – Drowsiness Gastric irritation Hepatic necrosis Renal tubular necrosis Methhemoglobinemia Hemolytic anaemia

Dose – Phenacetin 300 to 600 mgs (oral) Paracetamol 500 mgs (oral) Daily dose should not exceed 2.5g in adults.

Uses –

As a substitute for aspirin for pain and fever when aspirin is contraindicated.

3. PHENYLBUTAZONE

Adverse effects – Peptic ulcers Aplastic anaemia Agranulocytosis

Doses- Oral – 100 to 200 mgs tds with food IM – 600 mgs

4. OXYPHENBUTAZONE

A major active metabolite of phenylbutazone.

Just like phenylbutazone except-

i) Lesser gastric irritation.

ii) More effectively inhibits acute inflammation like inflammation due to trauma and hence has a place in minor oral surgery.

5. ANALGIN

A derivative of amidopyrine.A potent and promptly acting analgesic.It has a poor anti-inflammatory action.

Dose – Can be given orally, i.m. or i.v.i.v. injection can cause a fall in B.P.Available as tablets of 500 mgs or 2ml injections

containing 300 mgs

Adverse effects – Agranulocytosis Severe gastric irritation

6. APAZONE

An aspirin like pyranqolon agent with a spectrum of activity like phenylbutazone but less toxic.

It is anti-inflammatory, antipyretic, analgesic and uricosuric.

Rapidly absorbed on oral route and has a plasma half life of about 24 hours.

Dose – 1200 mgs/day

7. IODOMETHACIN

It has both central and peripheral action.It inhibits motility of neutrophils and hence can be a

disadvantage in diabetics

Adverse effects – Gastric irritation Diarrheoa Dizziness Depression Neutropenea Aplastic anaemia Thrombocytopenia

Doses –25 mgs twice daily

8. SULINDAC

Half as potent as indomethacin but with less gastric irritation.

It can precipitate a severe reaction in patients sensitive to aspirin

Doses –150mgs twice daily (oral)

Propionic acid derivatives

Have the following properties but vary in potency –i) Analgesic, antipyretic and anti inflammatory efficacy

is rated somewhat lower than a high dose of aspirin.

ii) All inhibit prostaglandin synthesis.iii) Inhibit platelet aggregation and prolong bleeding.iv) Less gastric irritation compared to aspirin but yet

the most common side effects are gastrointestinal.v) All are well absorbed orally.vi) Other side effects like headache. Dizziness and

vertigo.

1. IBUPROFEN

Enters synovial space slowly but remains there in high concentrations for a long time.

Interacts with coumarin and augments its effect. When used with aspirin, the net antiinflammatory

effect is reduced. Not indicated in pregnant women and in asthmatcs. Dose – 200 to 400 mg tds.

2. NAPROXEN

Absorption when given orally is reduced by aluminium hydroxide.

Dose – 250 mgs twice daily.

Anthranilic acid derivatives.

A family of aspirin like drugs.

3. MEFANAMIC ACID AND FLUFENAMIC ACID

As an antiinflammatory 1.5 times as powerful as phenylbutazone.

Has central and peripheral analgesic action . Also antipyretec. Inhibits prostaglandin synthesis.

Diarrhoea most common side effect. Dose – 500 mgs orally thrice daily.

Enfenamic acid (tromaril)

Extremely effective to control acute inflammations like inflammation following surgery. Also effective in chronic inflammations.

In has an antiprostaglandin effect. Gets localized in inflamed tissues. Good hastric tolerance.

Dose – 400 mgs orally twice daily.

1.DICLOFENAC

A phenyl acetic acid derivative. Possesses analgesic, antipyretic and

antiinflammatory activity similar to IBUPROFEN.

The drug accumulates in synovial fluid and hence an ideal drug in arthritis.

Causes GI tract irritation. Dose – 150 mgs twice daily.

2. TOLMETIN

An antiinflammatory, analgesic and antipyretic persists in synovial fluid for about 8 hours after a single oral dose and hence an excellent drug for arthritis.

GI bleeding, dyspepsia, drowsiness are the side effects.

Dose – 200 mgs thrice daily.

Oxicam derivetives

1.PROXICAM Equivalent to aspirin in long tern treatment of

arthritis. Half life 50 hours. Can cause GI tract bleeding and alteration in

platelet function. Causes bronchoconstriction in patients

hypersensitive to aspirin. Dose – 20 mg once daily.

Thank you