Analgesics i

8/11/2019 Analgesics i

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Presented by:Dr. Sugandha Sharma1st year PG


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Essentials of Medical Pharmacology- K.D.Tripathi (5th Ed.)

Pharmacology and therapeutics for dentistry- Neidle and Yagiela (3rd Ed.)

Pharmacotherapeutics in Dentistry-Gangarosa, Ciarlone, JeskePharmacology

- Dale,Rang and Ritter (4th Ed.)Basic & Clinical Pharmacology

- Bertran And Katzung


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PainAnalgesics-Definition

Classification

Routes of administrationOpioids-Classification

Opioid receptorsMechanism of action

Morphine-ActionsMorphine analgesiaPharmacological actions

PharmacokineticsAdverse effectsTherapeutic usesContraindications


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Codeine Fentanyl Tramadol PethidineMethadonePentazocineNaloxone

Strategies To Minimize Side EffectsUses in dentistryConclusion


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An unpleasant sensory emotional experienceassociated with actual or potential tissuedamage, or described in terms of suchdamage

I SP

Types of pain:A. Nociceptive (Tissue) Pain

B. Neuropathic (Nerve) Pain


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Definition:Analgesic is a drug that selectively relieves pain by acting inthe CNS or on peripheral pain mechanisms, withoutsignificantly altering consciousness.

ClassificationA. Opioid/Narcotic/Morphine like analgesics

B. Non opioid/Non narcotic/Nonsteroidal anti-inflammatory drugs.


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Oral Intramuscular Inj. Intravenous Inj.

PCA: patient controlledanalgesia

Epidural Administration Transdermal, Creams, gels and foam


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Opium Classification of Narcotic-Analgesics

1. Natural Opium Alkaloids

-Morphine-Codeine-Papaverine

2. Semisynthetic Opiates

-Heroin-Pholcodeine-Oxycodone


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3. Synthetic Opioids- Meperidine- Fentanyl- Methadone- Dextropropoxyphene- Tramadol


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CNS

Depressant effects:

(a) Analgesia Strong analgesic Relief of dull, poorly localized visceral pain

Nociceptive pain relieved better than neuretic pain Suppression of pain perception is selective.


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(b) Sedation

(c) Mood and Subjective effects

(d) Respiratory centre

(e) Cough centre

(f) Temperature regulating centre

(g) Vasomotor centre


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Stimulant effects:

(a) CTZ

(b) Edinger Westphal Nucleus

(c) Vagal centre


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CVS Causes Vasodilatation due to- Decreasing tone of blood vessels- Histamine release

GIT - Constipation.

NEUROENDOCRINE EFFECTS- Hypothalmic influence on pituitary is reduced.- Decreases levels of LH, FSH, ACTH whereasPROLACTIN & GH levels are increased.


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Smooth muscles- Biliary tract

- Urinary bladder

- Bronchi


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Oral absorption-Unreliable(High First pass Metabolism).Primarily metabolised in liver.

Freely crosses the placenta &can effect the foetus.


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1) Side Effects:Sedation, mental clouding, lethargyVomitingConstipationRespiratory depressionBlurring of visionUrinary retention


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2) Idiosyncrasy allergy

3) Apnoea- This may occur in new born when morphine is given tomother during labour.

-Treatment of choice Naloxone 10 ug /kginjected in the chord.


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4)Acute morphine poisoningIt is accidental ,suicidal or seen in drug abusers

Symptoms

Shallow & occasional breathing ,cyanosis ,pinpoint pupil ,fallin BP & shock .

Treatment

Respiratory support and maintenance of BPSpecific antidote Naloxone 0.4-0.8mg i.v


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5) Tolerance & dependenceHigh degree of tolerance if used repeatedly .

Withdrawal symptoms

Lacrimation ,sweating ,anxiety ,fear ,restlessness, tremor ,insomnia,

abdominal colic, diarrhoea.

Treatment Withdrawal of morphine &substitution with methadone


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Bronchial AsthmaInfants & ElderlyHead Injury

Undiagnosed AcuteAbdominal pain.Respiratory diseases(Emphysema, COPD)


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Equal analgesic efficacy to morphine

UNLIKE MORPHINE:- Less histamine release(Safer in ASTHMATICS)

- Less constipation

Used primarily as an analgesic (substitute of morphine)DOSE: 50-100 mg i.m, s.c/ orally(PETHIDINE HCL)100mg/ 2ml inj.;50-100mg Tab.)


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80 to 100 times more potent thanmorphine

Rapidly Onset of action (5 min)

Used for anesthesia and analgesia

DurogesicTransdermal patch (25-75g/hr)

Transdermal fentanyl(Durogesic)

Fentanyl lozenges(Actiq)


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Centrally Acting Analgesic.Has dual Norepinephrine & Serotonin reuptake inhibitoryeffects .10 times potent than morphine & produces less adverseeffects. Used in mild to medium intensity shortlasting pain.

DOSE: 50-100 mg oral/ i.v. 4-6 hrly(CONTRAMAL, DOMADOL)


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Mixed opioid agonist-antagonist action.Efficacy lower than morphine.Useful in Mild-Moderate pain conditions.Causes Tachycardia & rise in BP.Should not be used in opioid dependent subjects.

DOSE: 50-100 mg oral , 30-60 mg i.m /s.c(FORTWIN, FORTSTAR)


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No analgesic activity at all.Competitive antagonist at opioidreceptor & reverses all actions of morphine.Drug of choice for Morphine Poisoning.

Diagnosis of opioid dependence -it will precipitatewithdrawal reactions.

DOSE: 0.4 mg in 1 ml (NARCOTAN)


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Slow titration of doses.Changing the dosing regimen or route ofadministration.

Using a Nonopioid or Adjuvant Analgesic for anopioid sparing effect.Adding a drug to counteract the side effect.Constipation prophylaxis.
http://www.google.co.in/imgres?imgurl=http://www.toothachepainreliefsite.org/wp-content/uploads/2010/02/www.toothachepainrelieft.org_.jpg&imgrefurl=http://www.toothachepainreliefsite.org/&usg=__ywzDhk3wiusn_j8lJU3Dz50EX5U=&h=1024&w=1024&sz=160&hl=en&start=11&zoom=1&um=1&itbs=1&tbnid=ScoQujIeDHRmGM:&tbnh=150&tbnw=150&prev=/images?q=toothache+pain+relief&um=1&hl=en&tbs=isch:1


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Preanaesthetic medication

Postoperative pain

Fracture pain

Carcinoma
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Analgesics i