Analgesic Drugs

1

• Analgesic Drugs

2
Understanding Pain

• Most common symptom prompting people to seek
  health care
• Occurs when tissue damage activates free nerve
  endings of peripheral nerves
• Cerebral cortex analyzes messages and determines
  actions
• Activation of opiate receptors in CNS inhibits
  pain transmission

3
Understanding Pain

• Pain is a subjective experience
• People differ in their perceptions, behavior and
  tolerance of pain
• Stressors increase pain
• Diversionary activities tend to decrease pain-
• deep breathing, listening to music, visual
  imagery, others?
• Acute pain can be super-imposed on chronic pain

4

• Try alternative measures for pain control in
  addition to drugs
• Promote circulation and musculoskeletal function
• Use heat or cold as ordered
• Relieve pain ASAP
• Administer analgesic before pain producing
  activities
• Use the least amount of the mildest drug likely
  to be effective

5
Types of Pain

• Acute pain
• Chronic pain
• Superficial pain
• Deep pain

6
NARCOTICSOPIOIDS

• Opioid-any derivative of opium plant or any
  synthetic drug that imitates natural narcotics
• Opioid agonists-include opium derivatives and
  synthetic drugs w/similar properties (Kee p.332)
• Decrease pain without losing consciousness
• Opioid antagonists
• Block effects of opioid agnoists
• Used to reverse drug reactions-RD, CNS depression
• Narcan (always keep antagonist nearby)

7

• Opioid agonists
• Any route
• Inhalation uncommon
• Absorbed from GI tract
• Transmucosal / intrathecal fast acting
• IV provides most rapid and almost immediate
• Sub Q and IM delayed absorption
• Poor circulation can cause further delay
• Metabolized extensively in the liver
• Administration of meperedine gt 48 hours increases
  risk of neurotoxicity and seizures from buildup

8

• Pharmacodynamics
• Reduce pain by binding to opiate receptors in
  PNS/CNS
• Stimulation of opiate receptors-mimic effects of
  endorphins the bodys naturally occurring
  opiates
• Cause dilation of blood vessels in head, neck,
  face could result in increased cranial pressure
• With the exception of Demerol, suppress cough
  center to have antitussive effect
• Adverse / Side effects include constipation,
  respiratory depression, nausea, vomiting, urinary
  retention, orthostatic hypotension
• Morphine relieve dyspna r/t pulmonary edema

9

• Nursing process
• Assess pain before and after administration
• Monitor for adverse reactions / side effects
• Monitor for tolerance dependence
• Shortened duration of effect
• Evaluate respiratory status before each dose
• Respiratory depression
• Restlessness

10
Mechanisms by Which Opioid Analgesics Work

• Reduce the perception of pain sensation
• Produce sedation
• Decrease emotional upsets associated with pain

11
Characteristics of Opioid Analgesics

• Most are Schedule II or III drugs
• Morphine (MSO4) is the prototype
• May be given PO, IV, IM, SQ, or topically
• Oral drugs undergo significant first-pass
  metabolism
• Metabolized by liver and excreted in urine

12

• Exert CNS effects
• Use cautiously in clients with renal or hepatic
  disease, respiratory depression or increased
  intracranial pressure
• Exert depressant effect on GI tract
• Not recommended for prolonged periods of use
  except with chronic pain or malignant diseases

13
Morphine

• Naturally occurring opium alkaloid
• Used to relieve severe pain
• Maximum analgesia occurs in 10-20 minutes with IV
  route
• Controlled released tablets given for chronic
  pain
• May be given intrathecally or epidurally
• Route determines time interval or frequency of
  administration

14
Hydromorphone(Dilaudid)

• Synthetic derivative of morphine
• Same actions, uses, adverse effects as morphine
• More potent on a mg per mg basis
• More effective orally than morphine
• Effects last longer than morphine

15
Meperidine(Demerol)

• Synthetic drug similar to morphine
• Dose of 100mg is equivalent to Morphine
  10mg
• Has shorter duration
• Has less respiratory depression and little
  antitussive effect
• Causes less smooth muscle spasm

16
Codeine

• Naturally occurring opium alkaloid
• Used for milder pain
• Acts as an antitussive (found in cough meds)
• Often combined with acetaminophen
• Preferred analgesic with head trauma

17
Oxycodone

• Semisynthetic derivative of codeine
• Used to relieve moderate pain
• More potent and more likely to produce abuse than
  codeine
• Available in combination with acetaminophen

18
Opioid Antagonists

• Reverse or block analgesia, CNS and respiratory
  depression of opioid agonists
• Compete with opioids for opioid receptor sites in
  brain
• Do not relieve depressant effects of
  anti-anxiety drugs or antipsychotics
• Naloxone - oldest, most commonly known
• Nalmefene - newer with longer duration
• Naltrexone - used in maintenance of opiate free
  states in opiate addicts

19
Client Teaching For Opioid Analgesics

• Narcotics may be alternated with a
  non-narcotic analgesic
• If pain relief not achieved notify physician
• Do not drink alcohol or take other drugs that
  cause drowsiness
• Do not smoke, cook, drive a car or operate
  machinery after taking

20

• Constipation is a common adverse effect
• Do not crush or chew long acting tablets
• Decrease dose or omit if adverse effects occur

21
Use In Older Adults

• Use cautiously if debilitated or hepatic, renal
  or respiratory impairment
• Start with lower dose and increase gradually
• Give less often?
• Give opioid analgesic with short half-life
  (Oxycodone)
• Monitor for sedation or confusion
• Monitor urinary output
• Assess ability to self-medicate

22
Characteristics of Withdrawal From Opiates

• Generalized body aches
• Insomnia
• Lacrimation
• Rhinorrhea
• Perspiration
• Pupil dilation

• Piloerection
• Anorexia
• N/V/D
• Increased vital signs
• Abdominal and other muscle cramps

23
Treatment Of Withdrawal Syndrome

• Gradually reduce the opioid over several days
• Substitute methadone and slowly reduce dose over
  a longer time
• Clonidine reduces withdrawal symptoms

24
NONNARCOTICSSALICYLATES

• Salicylates-produce peripheral blood vessel
  dilation
• Most common pain reliever
• Control pain
• Reduce fever-stimulate hypothalmus
• Reduce inflammation
• ASA is oldest nonnarcotic analgesic
• Bonus effect-inhibits platelet aggregrate
• Guideline
• Use lowest dose that produces analgesia
• Highly protein bound-can interfere w/other drugs
• Heparin,methotrexate, oral antidiabetic meds,
  insulin

25

• Adverse reactions
• Hearing loss
• Diarrhea
• Thirst
• Sweating
• Tinnitus
• Confusion
• Dizziness
• Impaired vision
• Hyperventilation
• Reyes syndrome-when given to children (do not
  use lt 12 yrs old)
• Common side effects
• Gastric distress
• Bleeding tendencies
• NVD

26

• Give w/food
• May crush except enteric coated
• Hold and notify MD for bleeding
• Stop ASA 5-7 days before elective surgery
• Salicylate hypersensitivity
• Tinnitus or hearing loss
• Vertigo
• Bronchospasm
• Urticaria
• Need to avoid prunes, raisins, paprika, licorice

27
ACETAMINOPHEN

• Acetaminophen
• Antipyretic and analgesic
• IS NOT ANTI INFLAMMATORY
• Drug of choice for children with flulike symptoms
• Risk of liver disease
• Phenytoin, barbituates, INH, ETOH
• Rarely cause GI distress-may cause LIVER toxicity
• Monitor total daily dose (adults 4g max.)

28

• Phenazopyridine hydrochloride
• Pyridium-now OTC
• Dye used in commercial coloring-analgesic effect
  on urinary tract
• Relieves pain, burning, itching, urgency,
• Teach
• Urine orange
• Stains fabric-contact lenses
• Notify in ineffective

29

• Anti Inflammatory Drugs

30

• Anti inflammatory agents
• Reduce body temperature
• Relief of pain
• Anticoagulant (ASA)
• Reduce inflammation
• ASA oldest
• NSAIDS- reduce inflammation pain for arthritic
  conditions
• Inhibit enzyme COX

31

• OTC
• Ibuprofen, Motrin, Nuprin, Advil, Medipren
• Naproxen (Aleve)
• Motrin only available in 200 mg form
• MD must prescribe higher dose

32

• Second generation NSAIDS
• COX-2 inhibitors
• COX 1 inhibitor
• Decreased protection of lining of stomach
• Clotting time decreased-benefit cardiovascular
  patients

33

• NSAIDS
• Inhibit prostaglandin synthesis
• Prostaglandins produced / released in
  inflammatory disorders
• Ankylosing spondylitis
• Moderate to severe arthritis
• Osteoarthritis
• Acute gouty arthritis
• Dysmenorrhea
• Migranes
• Bursitis, tendonitis

34

• Adverse reactions
• Abdominal pain, bleeding
• Anorexia
• Diarrhea, nausea
• Ulcers
• Liver toxicity
• Drowsiness
• Headache
• Tinnitus
• Confusion
• Vertigo
• Depression
• Blood in urine, bladder infection, kidney
  necrosis
• Sodium water retention
• Heart failure
• Pedal edema

35

• Nursing implications
• CBC, platelet count, PT
• Monitor hepatic / renal function
• Bronchospasm
• Monitor for s/s of bleeding
• Take w/meals
• Avoid alcohol

36

• Corticosteroids
• prednisone / prednisolone / dexamethasone
• Suppresses components of inflammatory process at
  the injured site
• NOT THE DRUG OF CHOICE FOR ARTHRITIC CONDITIONS
• USED TO CONTROL FLARE UPS
• Must taper dose when D/C

37

• DMARDS-disease modifying antirheumatic drugs
• Toxic
• Alter disease process
• Gold/Gold Salts
• IM/PO
• Used for relief of symptoms
• Immunosuppressive agents-used when
  antiinflammatories do not work-cytoxan,
  methotexrate/cancer drugs
• Antimalarials-when all other tx fails

38

• Antiinflammatory Gout Drugs
• gouty arthritis
• Urinary calculi
• Gouty nephrophaty
• Increase fluid intake
• Avoid foods rich in purine - organ meats,
  sardines, salmon, gravy, legumes
• Avoid alcohol, caffeine, large doses of vitamin C
• Zyloprim - inhibits final steps of uric acid
• Colchicine - first drug, inhibits migration of
  leukocytes to the inflamed site

39
Propionic Acid Derivatives

• Ibuprofen (Motrin) - prototype ketoprofen
  (Orudis), naproxen (Naprosyn)
  
• Used as anti-inflammatory agents in gout,
  arthritis, tendonitis
• Used as analgesic for dysmenorrhea, episiotomy,
  minor trauma
• Used as antipyretic

40

• Better tolerated than ASA but more expensive
• Similar adverse affects as with ASA
• May lead to renal impairment
• Inhibits platelets only while drug molecules in
  bloodstream
• Combined with other drugs

41
Acetic Acid Derivatives

• Indomethacin (Indocin) - prototype Tolmetin
  (Tolectin), Sulindac (Clinoril)
• Used to treat moderate to severe rheumatoid
  arthritis, osteo-arthritis, gouty arthritis,
  bursitis, pericarditis for anti-inflammatory
  effects
• Prescription drug
• Has increased incidence and severity of adverse
  effects

42
Client Teaching Guidelines

• Take ASA and NSAIDS with full glass of water and
  food
• Drink 2-3 quarts of fluid daily with NSAIDS
• Report signs of bleeding
• Avoid or minimize alcoholic beverages
• Do not take more than prescribed amount
• Do not take more that 3 days for fever or 10
  days for pain
• Read labels of other OTC medications