Chapter 4: Bone and Joint Disorders Flashcards
NSAID drugs
ASA
Tylenol
Ibuprofen
Mobic
GI upset with NSAID usage
prescribe an H2 blocker with it
Duration of Ibuprofen/ASA usage before re-evaluation is necessary
follow up is needed if routine use exceeds 3 days
Perferred NSAID for mild-moderate pain with no inflammation
Acetominophen
Preferred NSAID for fever reduction
Ibuprofen
ASA
How long does it take to see improvement in arthritic conditions
Can take up to 2 weeks
Higher than recommended doses of NSAIDs
does not increase effect but does increase liklihood of side effects
NSAIDS pharmacokinetics
absorption: rapidly and completely from the GI tract
distribution: crosses placenta
metabolism: liver
excretion: urine
half-life: varies
Do NSAIDS enter breast milk
naproxen does
ibuprofen does not
NSAIDs and low dose aspirin
May lower cardioprotective effect
NSAIDs and diabetic medications
may increase hypoglycemic effect
Medications that cause increased bleeding risk when given with NSAIDs
Cefotan
valproic acid
thrombolytics
warfarin
drugs affecting platelets
What natural substances increase bleeding risk if given with NSAIDs
arnica
chamomile
garlic
ginger
ginseng
ginko
Comorbidities that can contraindicate NSAID usage d/t increased risk of GI bleeding
history of ulcers
advanced age
poor health
smoking
alcohol use
Comorbidities that contraindicate NSAID usage
renal impairment
heart failure
hypertension
NSAIDs in pregnancy
may cause pulmonary HTN in fetus
contraindicated in 3rd trimester as it can cause premature closing of ductus arteriosus after birth
Aspirin generic name
Acetylsalicylic acid
Aspirin actions
Analgesic
Antipyretic
anti-inflammatory
antiplatelet
salicylism
salicylate intoxication
symptoms of salicylism
headache, dizziness, tinnitus, hearing loss, mental disturbances, sweating, thirst, hyperventilation, N/V, diarrhea
how soon is treatment needed in severe salicylism
1-2 hours
Anagesic action of ASA
low-moderate pain (HA, myalgia, arthraligia)
ANtipyretic effect of ASA
reset the thermostat of the hypothalmus to normal
heat is lost as a result of cutaneous vasodilation and sweating
Duration of usage for acetominophen
5 days in children and no more than 10 in adults because of hepatic risks
Anti-inflammatory effect of ASA
inhibition of prostaglandin and thromboxane synthesis is the mechanism of anti-inflammatory action
Why are higher doses of ASA needed for anti-inflammatory effect than analgesic and antipyretic effects?
ASA has a stronger effect on COX-1 than COX-2
inflammation mainly affects COX-2
therefore higher doses of aspirin are needed to properly inhibit COX-2
Anti-platelet effect of ASA
causes alteration of platelet aggregation
Acetylation effect of ASA
reduces the formation of thromboxane needed for platelet aggregation.
This inhibitory effect lasts up to 8 days until new plateets are formed
ASA absorption
absorption: some in stomach but mostly in upper small intestines
ASA plasma concentration levels
significant after 30 minutes with peak at 1-2 hours
ASA distribution
rapid and primarily by pH dependent passive diffusion
crosses placenta and enters breast milk
ASA metabolism
primarily in liver
metabolism of high-toxic doses of ASA
metabolism is limited and occurs according to zero-order kinetics
metabolism of low doses of ASA
proceed according to first-order kinetics
why is it important to understand the biphasic metabolism of ASA
the difference in rate of metabolism is important to drug accumulation with repeated high doses
ASA excretion
In urine (dependent on pH)
alkalization of urine (raise in pH) can markedly increase clearance
from 2-80%
ASA half-life
low dose: 3-6 hours
high dose: 15-30 hours
ASA dose: mild pain and fever
325-650mg
4-6 times a day
ASA dose: antiplatelet
40-80mg/day
ASA dose: moderate arthritic pain
1gm 4-6 times/day
ASA side effects: CV
hypotension, tachycardia, dysrythmias, edema
ASA side effect: DERM
rash, angioedema, urticaria
ASA side effects: EENT
hearing loss
tinnitus
ASA side effects: GI
N/V, dyspepsia, heartburn, ulcers, gastric erosions, duodenal ulcers, hepatotoxicity, increased transaminases, hepatits
ASA side effects: GU
Interstitial nephritis, proteinuria, increased BUN/creat, papillary necrosis
ASA side effects: HEME
prolonged PT, iron deficiency anemia, thrombocytopenia
ASA side effects: MISC
ANAPHYLAXIS
Reye’s syndrome, low birth weight, prolonged labor
STILLBIRTH
ASA side effects: MS
rhabdomyolysis, weakness
ASA side effects: NEURO
fatigue, insomnia, nervousness, agitation, confusion, dizziness, headache, lethary, hyperthermia, coma
ASA side effects: PULM
asthma, bronchospasm, dyspnea, hyperpnea, tachypnea, respiratory alkalosis
ASA drug interactions
blocks transport of PCN from CSF to blood
can block the effects of gout medications
anticoagulants, beta blockers, hydantoins, lithium, loop diuretics, probenecid, and salicylates
Acetominophen and coumadin
Chronic high dosing can increase bleeding risk
Acetominophen and alcohol use
Chronic high dosing with alcohol abuse can increase risk of hepatotoxicity
Tylenol actions
Analgesic
antipyretic
significantly less gastric iiritation
What does Acetominophen poisoning cause
hepatic necrosis over 7-8 days
Acetominophen poisonind Day 1
N/V diaphoresis
Acetominophen poisoning day 1-2
liver enzymes, ALT, bilirubin, and PT rise
Acetominophen poisoning day 3-4
peak hepatotoxicity
Acetominophen poisoning day 7-8
recovery or death
Tylenol’s anti-inflammatory effects
Not effective as an anti-inflammatory
What makes Tylenol preferable to aspirin
Des not have the gastric irritation, erosion, and bleeding
does not show evidence of crossover sensitivity
Tylenol mechanism of action
Inhibits COX-3 substances in brain and spinal cord
Why does Tylenol not cause the same gastric side effects as aspirin
It has no effect on COX-1 or COX-2
Tylenol: pharmacokinetics
absorption: incomplete and varies by dosage form
distribution: 80-40% protein bound
metabolism: liver
excretion: urine
half-life: 1-4 hours (may be prolonged in elderly)
Tylenol dose:
Adults and chilren over 14
325-650mg q4-6h
Not to exceed 4gm/day in people with renal impairment
Tylenol dose:
Children under 12
SHould not have more than 5 doses in a 24 hour period unless prescribed by health professional
Tylenol dose:
Osteoarthritis in adults
up to 1gm QID
not to exceed 4gm daily
Tylenol side effects: DERM
rash, urticaria
Tylenol side effect: GI
hepatic failure, hepatotoxicity
Tylenol side effects: GU
renal failure in high doses or chronic use
Tylenol Interactions
hepatotoxicity and liver damage additive with barbituates, alcohol
Misoprostol trade names
Arthrotec, Cytotec
What is the purpose of Cytotec
increase the production of mucus in the stomach and decreasing gastric acid secretion to decrease gastric mucosal injury of NSAIDs
cytotec: pharmacokinetics
absorption: rapid after oral administration
distribution: good bioavailability d/t methyl group
metabolism: parietal cells
excretion: urine
half-life: 20-40 minutes
Uses of cytotec
Patients with osteoarthritis at high risk for gastric ulcers
cytoec side effects: GI
abdominal pain, diarrhea, dyspepsia, N/V, flatulence
Cytotec side effects: NEURO
headache
cytotec side effects: OB/GYN
miscarriage, mentsrual disorders
medications which potentiate toxicity with cytotec
methotrexate
digoxin
cyclosporine
lithium
cytoec and K+ sparing diuretic
increased potassium
cytotec contraindications
pregnancy
patients senstive to prostaglandins
Patient education for cytotec
Avoid antacids (diarrhea)
diarrhea/black tarry stools may persist for one week
avoid alcohol
pregnancy implications
Ibuprofen uses
anti-inflammatory
relieves mild-moderate pain
antipyretic
rheumatoid arthritis
osteoarthritis
dysmenorrhea
Ibuprofen trade names
advil, motrin
ibuprofen mechanism of action
propionic acid derivative that inhibits cyclooxygenase
(inhibits prostaglandin synthesis)
ibuprofen: pharmacokinetics
absorption: rapidly (bound to protein)
distribution: hepatic
metabolism: hepatic via oxidation
excretion: renal
half-life: 2-4 hours
ibuprofen side effects: CV
arrythmias, edema
ibuprofen side effects: DERM
rash
ibuprofen side effects: EENT
amblyopia, blurry vision. tinnitus
ibuprofen interactions
may increase hypoglycemic effect of diabetic medications
increased bleeding risk
ibuprofen contraindications
sensitivity to ASA and other NSAIDs
chewable is contraindicated for patients with phenylketonuria
ibuprofen: caution in patients with
CV, renal, hepatic disease
especially elderly
meloxicam (mobic) mechanism of action
inhibits cyclooxygenase witch decreases biosynthesis of prostaglandins
Meloxicam pharmacokinetics
Absorption: plasma levels peak at 4-5 hours
distribution: unknown
metabolism: cytochrome P450 enzymes in liver to inactive metabolites
excretion: urine and feces
half-life: 15-20 hours
meloxicam clinical uses
rheumatoid arthritis
osteoarthritis
anti-inflammatory
analgesic
antopyretic
meloxicam side effects: DV
edema
meloxicam side effects: DERM
steven-johnson syndrome, toxic epidermal necrosis