Pain meds

Question 1

Pain Meds

Answer 1

NON-OPIOIDS:
* nonsterioidal anti-inflammatory drugs (NSAIDs)
* Acetaminophen
* Antiepilieptics
* Local anesthetics
OPIOIDS

Question 2

NSAIDs

facts

Answer 2

• for mild-to-moderate pain
• associated w/ inflammation
• temporary reduction of fever (children)
• No evidence for management of neuropathic pain
• Some have non-pain related indications (aspirin;2nd prevention use for MI)
  Remember: choice of agent depends on several factors (comorbities, risk for bleeding)
  *recommend Rx lowest effective dose for shortes pd.

Question 3

COX-1

Answer 3

1. Housekeeping enzyme primarly in the stomach
2. inducible activity (2-4X)
3. major product is thromboxane => induces platelet aggregation
4. inhibition of platelet COX-1 explains why aspiring effectively reduces cardiac events

Question 4

COX-2

Answer 4

1. Inflammatory Response
2. inducible activity (10-20X)
3. Kidney, lungs, inflammatory cells (macrophages)
4. both NSAIDs & glucocorticoids inhibit COX-2 gene expression => help reduce inflammation

Question 5

NSAIDs Meds

(8) generic (13) trade

Answer 5

1. Acetylated salicylates (aspirin)
2. Non-acetylated salicylates (diflunisal)
3. Propionic acids (ibuprofen, naproxen)
4. Acetic acids (indomethacin, diclofenac)
5. Anthranilic acids (meclofenamate, mefenamic acid)
6. Enolic acids (meloxicam, piroxicam)
7. Naphthylalanine (nabumetone)
8. Selective COX-2 inhibitors (celecoxib, etoricoxib)

Question 6

NSAIDs MOA

Answer 6

• inhibits cyclooxygenase => inhibits prostaglandin synthesis
• most inhibit both COX isoforms w/ little selectivity
• Higher affinity to one or another ( aspirin & coxibs) will exert antiinflammatory, analgesic, & antipyretic effects @ different degress

Question 7

NSAIDs ADRs

Answer 7

GI: N/C/D, anorexia, dyspeppsia, abd pain, ulcers, GI hemorrhaeg, perforation
Cardiovascular: HTN, decrease antihypertensive med effectiveness, MI, stroke, & thromboembolitic events (last 3 w/ selective COX-2 inhibitors) inhibit platelet activation, propensity for bruising & hemorrage
RENAL: salt & water retention, deterioration of kidney function, edema, decrease diuretic med effectiveness, urate excretion, hyperkalemia, analgesic nephropathy
CNS: HA, dizziness, vertigo, confusion, depression, lowering seizure threshold, hyperventilation (salicylates)
Hypersensitivity: vasomotor rhinits, asthma, urticaria, fluching, hypotension, shock
HEPATOTOXICITY

Question 8

NSAIDs CI

Answer 8

Hypersensitivity
only major CI

Question 9

NSAIDs conditions that demand AVOIDANCE, temporaty SESPENSION or CAUTION

Answer 9

• age >50 y.o.
• family hx of GI bleed/disorder
• uncontrolled HTN
• RENAL DISEASE
• IBS, IBD
• Coronary artery & gastric bypass surgery
• PREGNANCY => placental abruption
• STROKE, TIA, MI (excluding aspirin)

Question 10

NSAIDs drug interaction w/ ACE inhibitos

Answer 10

Severity: MODERATE
ADR: may decrease antihypertensive & natriuretic effects
Recommendation: monitor BP & cardiovascular function

Question 11

NSAIDs interaction w/ LITHIUM

Answer 11

Severity: MODERATE
ADR: may increase lithium plasma level & deccrease its clearance renally
Recommendation: monitor for lithium toxicity

Question 12

NSAIDs interaction w/ WARFARIN

Answer 12

Severity: MODERATE
ADR: may result in increase risk of bleeding
Recommendation: monitor PT & INR

Question 12

NSAIDs interaction w/ METHOTREXATE

Answer 12

Severity: SEVERE
ADR: may result in increase risk of methotrexate toxicity
Recommendation: DONT administer NSAIDs w/in 10 days of high dose methotrexate

Question 13

NSAIDs Nursing Assessment

Answer 13

MONITOR:
pts w/ chronical use & at risk for toxicity; should have evaluationg including CBC, RENAL, HEPATIC function test as a minimum
Most OD case are asymptomatic or develop insignificant self limiting GI symptoms
SERIOUS COMPLICATIONS: confusion, HA, nystagmus, drowsiness, blurred vision, diplopia, tinnitus, convulsion, metabolic acidosis, acute renal or liver failure, GI bleed, coma

Question 14

Acetaminophen (tylenol)

Answer 14

mild-to-moderate or moderate-to- severe pain
temporary reduction of FEVER
SHOULDNT be used for neuropathic pain theres no doc effect
Dose for ADULTS 650-1000mg Q4-6H, max 4g/day
Children dose 15mg/kg Q6H, up to 60mg/kg/day
Administer PO, Rectally or IV

Question 15

Acetaminophen MOA

Answer 15

Dimished activity of the COX pathway leads to decrease prostaglandin synthesis in the CNS =>inducing analgesia (serotonergic inhibitory pathways) & antipyresis (hypothalamic heat-reduction center)
* Unclear to date
* Lacks anti-inflammatory properties & DOESNT bind to the active site of either COX enzymes
* Hypothesis: inhibits different variant of COX-1 AKA COX-3; remains uncomfirmed in human studies

Question 16

Acetaminophen ADRs

Answer 16

depends on route of administration
* IV: N/C, pruritis, abd pain
* ORAL or RECTAL: may cause Rash or Hypersensitivity reaction ( TEN, acute generalized exanthematous pustulosis, & SJS)
* Hematological: anemia, leukopenia, neutropenia, pancytopenia
* Nephrotoxicity
* Metabolic & electrolyte disorders: decreased serum bicarbonate, hyponatremia, hypocalcemia, hyperammonenia, hyperchloremia, hyperuricemia, hyperglycemia, hyperbilirubinemia, elevated alkaline phosphate

Question 17

Acetaminophen CI

Answer 17

Hypersensitivity,
Severe hepatic impairment or disease
* Pregnancy is not a CI