NSAIDS Flashcards
Properties of NSAIDS
- Analgesic (relieves pain)
- Antipyretic (prevent or reduce fever)
- Anti-inflammatory
Acetylsalicylic acid (Aspirin)
Aspirin is the prototype salicylate and NSAID and is the most widely used drug in the world. A daily aspirin tablet (81 mg or 325 mg) is now routinely recommended as prophylactic therapy for adults who have strong risk factors for developing coronary artery disease or stroke. Also effective after a MI. The 81 mg strength & the 325 mg appear to be equally beneficial for the prevention of thrombotic events
- lower strength often chosen for patients who have elevated risk for bleeding, such as those with previous stroke history or history of peptic ulcer disease and those taking the anticoagulant warfarin (Coumadin)
- often used to treat the pain associated w/headache, neuralgia, myalgia, and arthralgia, as well as other pain syndromes resulting from inflammation which include arthritis, pleurisy, and pericarditis
- those w/ systemic lupus erythematosus may also benefit from aspirin therapy because of its antiheumatic effects
- also used for antipyretic action
- aspirin and other salicylates all have one very specific contraindication in children with flulike symptoms because the use of these drugs has been associated with Reye’s syndrome (acute potentially life threatening condition involving progressive neurologic deficits that can lead to coma and may also involve liver damage as well as by salicylate therapy itself, in the presence of a viral illness)
- survivors may or may not suffer permanent neurologic damage
Why is acetylsalicylic acid (aspirin) used?
For its effect in inhibiting platelet aggregation, which has been shown to have protective qualities against certain cardiovascular events such as myocardial infarction (MI) and stroke.
-has been shown to reduce cardiac death after MI and should be administered at the first sign of MI. If not given prior to arriving to the ER, it is one of the first drugs given if there are no contraindications
In 1899, acetylsalicylic acid (Aspirin) was marketed and rapidly became the most widely used drug in the world. The success of aspirin established the importance of drugs with antipyretic, analgesic, and antiinflammatory properties-properties that all NSAIDS share. The widespread used of Aspirin also yielded what?
Evidence of its potential for causing major adverse effects. Gastrointestinal intolerance, bleeding, and renal impairment became major limiting factors to its long-term administration
-As a result, efforts were mounted to develop drugs that did not have the adverse effects of aspirin. This led to the discovery of other NSAIDs, which are associated w/a lower incidence of and less serious adverse effects & often better tolerated than aspirin in patients with chronic diseases
NSAIDs mechanism of action
- Inhibition of leukotriene pathway, the prostaglandin pathway, or both
- relieve pain, headache, & inflammation by blocking the chemical activity of the enzyme called cyclooxygenase (COX); which has 2 types
- COX-1 promotes synthesis of prostaglandins
- COX-2 promotes synthesis of prostaglandins involved in inflammatory processes
- leukotriene pathway inhibited by some anti-inflammatory drugs, but not salicylates
- all can be ulcerogenic and induce GI bleeding
Platelet inhibition
Aspirin
One notable effect of aspirin is
Its inhibition of platelet aggregation, also known as antiplatelet activity
- Has the unique property among NSAIDs of being an irreversible inhibitor of COX-1 receptors w/in the platelets themselves. This in turn results in reduced formation of thromboxane A2, a substance that normally promotes platelet aggregation.
- This antiplatelet action has made aspirin a primary drug in the Tx of acute MI & many other thromboembolic disorders.
- Other NSAIDs lack these antiplatelet effects
Indications of NSAIDS
- Primarily used for their analgesic, antiinflammatory, and antipyretic effects, and for platelet inhibition
- also widely used for the Tx of rheumatoid arthritis & osteoarthritis, as well as other inflammatory conditions, rheumatic fever, mild-moderate pain, and acute gout
- beneficial as adjunctive pain relief in pt’s w/chronic pain syndromes
- sometimes combined w/opioid
- have opioid sharing effect when given together because the drugs attack pain using 2 diff. mechanisms
- show ceiling effect that limits their effectiveness
Contraindications for NSAIDs
- known drug allergy & conditions that place patient at risk for bleeding (Vit k def, peptic ulcer disease)
- pt’s w/documented aspirin allergy cannot take them
- pregnancy C drugs for use during first two trimesters
- pregnancy D not recommended for use during the third trimester because it has association w/both excessive maternal bleeding and neonatal toxicity during perinatal period
- not recommended for nursing mothers, excreted in milk
- pt’s undergoing surgery need to stop taking them 1 week prior
Adverse effects of NSAIDs
- Effect on GI tract (mild-severe, heart burn, GI bleeding)
- acute renal failure, especially if dehydrated
- many adverse effects are secondary to their inactivation of protective prostaglandins that help maintain normal integrity of stomach lining
- misoprostol (cytotec) can be giving with them to prevent gastric ulcers and GI bleeding
- all NSAIDs (except aspirin) share a black box warning regarding an increased risk for adverse cardiovascular thrombotic events, including fatal MI and stroke
- NSAIDs may counteract the cardioprotective effects of aspirin
Toxicity and management of overdose for NSAIDs
- tinnitus and hearing loss
- in children it includes hyperventilation and CNS effects such as dizziness, drowsiness, and behavioral changes
- metabolic acidosis and respiratory alkalosis
- hypoglycemia
- acute overdose of nonsalicylate NSAIDs cause similar effects but not as extensive or dangerous. Include CNS toxicities (drowsiness, lethargy, mental confusion, paresthesias, numbness, aggresive behavior, disorientation, and seizures, and GI toxicities such as N/V & GI bleeding
- Tx: administration of activated charcoal, w/supportive and symptomatic tx initiated thereafter
NSAIDs are a large and chemically diverse group of drugs with the following properties:
Analgesic
Antiinflammatory
Antipyretic
Aspirin-platelet inhibition
NSAIDs are also used for the relief of:
- Mild to moderate headaches
- Myalgia
- Neuralgia
- Arthralgia
- Alleviation of postoperative pain
- Relief of the pain associated with arthritic disorders, such as rheumatoid arthritis, juvenile arthritis, ankylosing spondylitis, and osteoarthritis
- Treatment of gout and hyperuricemia
NSAIDs mechanism of action (main points)
- Inhibition of the leukotriene pathway, the prostaglandin pathway, or both
- Blocking the chemical activity of the enzyme called cyclooxygenase (COX)
- Cyclooxygenase-1 (COX-1)
- Has a role in maintaining the GI mucosa
- Cyclooxygenase-2 (COX-2)
NSAIDs: Mechanism of action for aspirin main points
- Irreversible inhibitor of COX-1 receptors within the platelets themselves
- Reduced formation of thromboxane A2, a substance that normally promotes platelet aggregation
- Other NSAIDs lack these antiplatelet effects
The nurse is administering medications. One patient has an order for aspirin 325 mg by mouth daily and another patient has an order for aspirin 650 mg 4 to 6 times daily (maximum 4 g/day). The nurse understands that the indication for the 325 mg of aspirin once daily is pain management. fever reduction. treatment of osteoarthritis. thromboprevention.
thromboprevention.
- “Low-dose” aspirin, such as 81 or 325 mg once daily, is given for thromboprevention. Dosages for pain, fever, or arthritis are much higher usually.
Chemical categories of NSAIDs
- Salicylates
- Acetic acid derivatives
- Cyclooxygenase-2 (COX-2) inhibitors
- Enolic acid derivatives
- Propionic acid derivatives
Salicylates
- Salicylic acid (aspirin)
- Inhibits platelet aggregation
- Antithrombotic effect: used in the treatment of MI and other thromboembolic disorders
- Examples: aspirin, diflunisal (Dolobid), choline magnesium trisalicylate (Trilisate), and salsalate (Salsitab)
- Reye’s syndrome
Acetic Acid Derivatives
- indomethacin (Indocin)
- ketorolac (Toradol)
- diclofenac sodium (Voltaren)
- sulindac (Clinoril)
- tolmetin (Tolectin)
- etodolac (Lodine)
- meclofenamate (generic only)
- mefenamic acid (Ponstel)
Acetic Acid Derivatives
Used to treat rheumatoid arthritis, osteoarthritis, acute bursitis or tendonitis, ankylosing spondylitis, and acute gouty arthritis
Promote closure of patent ductus arteriosus, a heart defect that sometimes occurs in premature infants
Ketorolac (Toradol) has powerful analgesic effects
A hospitalized patient has an order for ketorolac (Toradol). The nurse notes that the order is only for 5 days. What is the reason for this?
The patient’s pain should subside by that time.
There are concerns about addiction to the drug.
The drug can cause severe renal and gastrointestinal effects.
The drug loses its effectiveness over time.
The drug can cause severe renal and gastrointestinal effects.
Rationale: The main adverse effects of ketorolac include renal impairment, edema, gastrointestinal pain, dyspepsia, and nausea. It is important to note that the drug can only be used for 5 days because of its potential adverse effects on the kidney and gastrointestinal tract.
COX-2 Inhibitor
- celecoxib (Celebrex)
- First and only remaining COX-2 inhibitor
- Indicated for osteoarthritis, rheumatoid arthritis, acute pain symptoms, ankylosing spondylitis, and primary dysmenorrhea
- Adverse effects include headache, sinus irritation, diarrhea, fatigue, dizziness, lower extremity edema, and hypertension
- Little effect on platelet function
- Celecoxib is not to be used in patients with known sulfa allergy
Propionic Acid Derivatives (names)
fenoprofen (Nalfon) flurbiprofen (Ansaid) ibuprofen (Motrin, Advil) ketoprofen (Orudis KT) naproxen (Naprosyn, Aleve) oxaprozin (Daypro)
