Lecture Pain

Question 1

Immediate goal of pain management

Answer 1

to reduce pain to a level that allows patient to perform reasonable ADLs.

Patient should be considered expert of his or her own pain.

Pain management is a patient right.

Try to get patient in steady state of pain relief rather than react to pain

Dosing should be individualized and adjusted.

i) Adverse effects should be anticipated and prevented whenever possible.
ii) Around-the-clock dosing should be implemented for moderate/severe pain.
iii) Easier to maintain pain-free level than eliminate existing, escalating pain

Question 2

Analgesia

Answer 2

Loss of sensibility to pain

Question 3

Anesthesia

Answer 3

Loss of pain and loss of all other sensation

Question 4

Acute pain

Answer 4

pain with abrupt onset but brief duration; <6 months

Question 5

Chronic pain

Answer 5

pain lasting longer than 6 months

Question 6

Maximum daily dose of acetaminophen

Answer 6

4000mg

Question 7

opioid agonists

Answer 7

(1) Activate mu and kappa receptors
(2) Relieve moderate to severe pain
(3) large effect with large dose

Morphine, fentanyl, meperidine, methadone, hydromorphone, codeine, oxycodone, hydrocodone

Question 8

mixed opioid agonist-antagonist

Answer 8

(1) Work on one receptor but block or have no effect on another
(2) Treat moderate pain with less risk
(3) less risk, less side effects, moderate pain treatment

pantazoin, nalvuphine, butophanol

Question 9

opioid antagonist

Answer 9

(1) Block mu and kappa receptors
(2) Treat opioid overdose
(3) Naloxone

Question 10

adverse effects of opioids:

Answer 10

GI effects

(1) Nausea, vomiting
(2) Constipation

CNS depression

(1) Sedation
(2) Euphoria
(3) Intense relaxation

Other

(1) Pruritus
(2) Respiratory depression
(3) Orthostatic hypotension
(4) Increased intracranial pressure (ICP)
(5) Risk of physical and psychological dependence
(6) Dizziness, hallucinations, anxiety
(7) Tolerance
(8) Urinary Retention

Question 11

Morphine AE:

Answer 11

Respiratory depression

(a) (min) IV 7, IM 30, SQ 90
(b) Infants and elderly esp susceptible to resp depression

Constipation

(a) impaction, bowel perforation, rectal tear, hemorrhoids
(b) interventions include: increase physical activity, increase fluids and fiber, stool softener, stimulant laxative

Orthostatic hypotension 
(a)	sit/lay down – rise slowly

Urinary retention & urgency

Cough suppression
(a) Can cause ↑ accumulation of secretions so have pt cough and deep breathe

N/V, Euphoria, Miosis, Sedation, Tolerance, Physical dependence

Question 12

Abstinence syndrome from abrupt stop of Morphine

Answer 12

~10 hours

Initially: Yawning, rhinorrhea, sweating

Later: Violent sneezing, weakness, N/V/D, abdominal cramps, bone/muscle pain, muscle spams, kicking movements

7 – 10 days if untreated

Won’t die from detox, but will be painful

Question 13

Morphine toxicity

Answer 13

Classic triad - coma, respiratory depression, pinpoint pupils

Interventions

(a) Ventilator support
(b) naloxone [Narcan]

Question 14

fentanyl

Answer 14

100 x more potent than morphine

Via 3 routes
Parenteral - surgical anesthesia
Transdermal - patch (heat acceleration), iontophoretic; uses electricity to deliver (almost like a needle)
Transmucosal - lozenge, buccal film/tablet, sublingual tab/spray

Question 15

meperidine [Demerol]

Answer 15

Naloxone [Narcan] does NOT reverse meperidine!!

short ½ life, toxic metabolite accumulation

Question 16

hydromorphone

Answer 16

Often used as PCA

Less nausea but more othostatic hypotension than morphine

More rapid onset, but shorter duration of activity than morphine

Question 17

codeine

Answer 17

moderate to strong opioid agonist used for pain & cough suppression

usually oral (alone or with aspirin or acetaminophen)

30 mg = 325 mg acetaminophen

Question 18

oxycodone

Answer 18

analgesia about the same as codeine

immediate vs extended release (ER) -> breakthrough vs chronic pain

OxyContin – abuse – crush & snort/inject
BUT new formulation (2010) harder to crush & doesn’t dissolve into injectable solution

Question 19

hydrocodone

Answer 19

most widely prescribed drug in U.S.

combined with ASA, acetaminophen [Lortab], ibuprofen [Vicodin]

in these combos watch for max acetaminophen dose (4000mg/day) - can go over if take tylenol in addition to meds

Question 20

Naltrexone

Answer 20

used for opioid and alcohol abuse

Question 21

NSAIDs

Answer 21

Three major classes of NSAIDs

i) Salicylates
ii) Ibuprofen and ibuprofen-like agents
iii) Cyclooxygenase-2 (COX-2) inhibitors

Aspirin & ibuprofen are the Drugs of choice

Indications

(1) Have antipyretic and anti-inflammatory properties
(2) Act at peripheral sites, inhibiting pain mediators at nociceptor level

AEs

(1) Do not produce severe adverse effects of narcotics
(2) No physical, psychological dependence
(3) Most prominent effects are GI related, Ulceration of mucosa

Question 22

tramadol [Ultram]

Answer 22

Moderate pain

bind to mu receptor (so considered a mild opioid)

Inhibits transmission of pain impulses

A/E:

(1) Seizures
(2) Respiratory depression

Overdose: naloxone

Question 23

clonidine [Duraclon]

Answer 23

intrathecal (injected into spinal cord)

adjunct for cancer pain

AEs: severe hypotension, rebound HTN, bradycardia

Question 24

aspirin [Acetylsalicylic Acid]

Answer 24

first generation salicylate

Indications

i) Analgesic
ii) Anti-inflammatory
iii) Antipyretic
iv) Suppress platelet aggregation

COX 1 & 2 inhibitor

Has adverse effects on GI mucosa:(1) Stomach irritation/pain, Heartburn, N/V, Diarrhea, GI bleeding

also Tinnitus and Reye’s syndrome

Question 25

Ibuprofen Like Drugs

Answer 25

the most common drugs for treating mild to moderate pain and inflammation.

Indications:

i) analgesic,
ii) anti-inflammatory, and
iii) antipyretic

All inhibit COX 1 and 2

AE:

i) Can damage GI mucosa – risk for GI bleeding!
ii) Many are nephrotoxic at high doses.

Ibuprofen, Ketorolac, Naproxen

Question 26

Ibuprofen interactions

Answer 26

(1) Oral anticoagulants can increase risk of bleeding

(2) Other NSAIDs, alcohol, or corticosteroids may cause serious adverse GI events

Question 27

Ibuprofen OD treatment

Answer 27

(1) Administration of activated charcoal and nasogastric suction

Question 28

COX 2 inhibitors

Answer 28

Second-generation anti-inflammatory

Block COX-2 but not COX-1

Less GI bleeding and ulcer formation than with ibuprofen or aspirin

Limited use due to risk of MI and stroke (Increased risk)

celecoxib [Celebrex]

Question 29

celecoxib [Celebrex]

Answer 29

COX 2 inhibiotr

anti-inflammatory

AE:

(1) Dyspepsia, abdominal pain,
(2) sulfonamide allergy
(3) Serious adverse effects
(a) MI that can be fatal
(b) Stroke
(c) HTN, Peripheral edema, Renal and hepatic impairment

Interactions: Reduced antihypertensive action of diuretics or ACE inhibitors

OD: same as ibuprofen (activated charcoal and nasogastric suction)

Question 30

acetaminophen

Answer 30

aka APAP, Paracetamol, ofirmev

Indications:

i) Analgesic,
ii) antipyretic
iii) **NOT anti-inflammatory (or antirheumatic action)

Not an NSAID

iii) Does not cause GI bleeding or ulcers
iv) Often combined with opioid analgesics
(1) Acetaminophen and ibuprofen together = hydrocodone!!

Question 31

acetaminophen and alcoholics

Answer 31

Assess alcohol use – if 3+EtOH, <2000 mg / day

Question 32

acetaminophen OD

Answer 32

Treatment: acetylsteine (Mucomyst, Acetadote)

usually occurs w/in 8-10 hours of ingestion