NSAIDs and Gout Flashcards
NSAIDs - MoA
Inhibition of prostaglandin synthesis by competitive cyclooxygenase (COX) inhibition
NSAIDs - Clinical use
Low dose: mild-moderate pain, antipyretic Higher doses: inflammation. Postop pain (often combined with opioid) Chronic pain
NSAIDs - Contraindications
Avoid treatment with two NSAIDs (increased GI bleeding risk).
Generally not recommended for second half of pregnancy
Previous severe hypersensitivity to salicylates (cross-sensitivity)
NSAIDs - Adverse
GI bleeding, peptic ulcers, renal & hepatic dysfunction. Lithium toxicity. Hyperkalemia Platelet inhibition Premature closure of ductus arteriosus
NSAIDs - Interactions
Inhibit renal excretion of lithium.
Reduced clearance of aminoglycosides & methotrexates.
Interfere with antihypertensive effect of: diuretics, β-adrenoceptor antagonists, angiotensin inhibitors & others.
Potassium-sparing diuretics: hyperkalemia
Salicylates - MoA
Nonspecific inhibition of COX
Salicylates - Clinical use
Pain, fever, inflammation
Prophylaxis for MI, stroke, thromboembolic disorders
Salicylates - Contraindications and Overdose treatment
Avoid in children: Reye syndrome (in virus infected children).
Overdose treatment: Vomiting IV sodium bicarbonate (alkalization of the urine, increases ionization and elimination) Fluids Electrolytes
Salicylates - Adverse
Reye syndrome
Salicylates - Interaction
Hypoglycemic effect alter antidiabetic drugs
Aspirin - MoA
Forms covalent, irreversible inhibition of COX in platelets
Nonspecific inh of COX in peripheral tissues and CNS
Aspirin - Clinical use
Analgesic
Antipyretic
Anti-inflammatory
Aspirin - Adverse
Aspirin toxicity
High dose:
Tinnitus (early sign of salicylate toxicity)
Hyperventilation
Fever, dehydration, severe metabolic acidosis
If not treated: Shock, coma, organ system failure, death
Hypoprothrombinemia – impairment of hemostatis and bleeding
Hypersensitivity – anaphylaxis (mostly pt with asthma, nasal polyps, chronic urticaria)
Symptoms of aspirin intolerance: vasomotor rhinitis, angioedema, urticaria
Aspirin - Interactions and contraindication
Adm with antacids: slows absorption rate
Contraindication:
Persons who have has severe hypersensitivity reaction to aspirin or another salicylate should not be treated with another type of NSAID (cross-sensitivity)
Ibuprofen - MoA
Reversible and nonselective inh of COX
Ibuprofen, Ketoprofen, Naproxen - Clinical use
Analgesic, antipyretic and anti-inflammatory effects
Low dose: mild pain & inflammation
Higher dose: arthritis
Ibuprofen - Special
Combo with H2 receptor antagonist famotidine for RA & OA (less GI ulcers)
Half-life: 2h
Ibuprofen - Adverse
GI irritation, nausea, dyspepsia, bleeding.
Long-term: PUD,
Hepatotoxicity, renal toxicity
Failure of ingesting adequate fluid: acute renal failure
Naproxen - Special
Combo with esomeprazole: arthritis, reduces risk of ulcers
Longer halflife (14h)
Acetaminophen - MoA
COX3 inhibitor
Acetaminophen - Clincal use
Mild fever & pain
Mild arthritis
Analgesic and antipyretic effects via inh of COX
Acetaminophen - Special consideration and Overdose treatment
Safe for children with viral inf.
Overdose treatment: acetylcysteine
Can be used with other NSAID of supplemental analgesia. Should be avoided.
Acetaminophen - Adverse
Fewer GI problems
Low doses ok in pregnancy for analgesia & antipyresis
High dose: hepatic necrosis, hepatotoxicity
Long-term use: Increased risk of renal dysfunction
Acetaminophen - Interactions
Small amount converted by CYT P-450 to potentially hepatotoxic quinone intermediate
Patients at risk for hepatotoxicity (f.ex. overdose): given acetylcysteine (conjugates quinone and renders it harmless)
