Flashcards in NSAIDs and Acetaminophen Deck (84)
Types of pain
-Nociceptive (somatic, visceral)
What is the mechanism of pain and what are its mediators?
Describe the stages of the neural pain pathway
What occurs in the stimulation phase of the neural pain pathway?
-Noxious stimuli activate receptors
-Release of bradykinins, H and K ions, PGs, histamine, ILs, TNF, serotonin and Sub P
What occurs in the transmission phase of the neural pain pathway?
-A and C afferent nerve fibers stimulated
-Synapse along spinal cord dorsal horn releases NTs
-Impulses passed along ascending pathway to the brain
What occurs in the modulation phase of the neural pain pathway?
-Pain becomes a conscious experience via limbic system
-Endogenous opiate system in CNS modulates pain impulses
-Descending system of nerves may inhibit synaptic pain transmission
-Subset of nociceptive pain
-Natural shift from protection of damage to promotion of healing
Describe maladaptive inflammation
-Action outlives function
-Chemical properties of neurons change which effects transmission of pain
-Often caused by disease
What is the beginning component of the COX pathway normally?
(released upon trigger of natural inflammatory cascade)
General function of COX?
Oxygenates arachidonic acid which forms PGs, prostacyclin, thromboxane
What is misoprostol and what does it do?
-Induces uterine contractions
-Protects GI mucosa
What is alprostadil and what does it do?
-Maintain patent ductus arteriosis
What is latanoprost and what does it do?
-Treatment of open angle glaucoma
What is prostacyclin and what does it do?
-Treatment of pulmonary HTN
Describe selective NSAIDs
Selectively blocks COX-2 (over COX-1)
-GI, renal blood flow
Activated only as needed
-Inflammation, fever, pain
Major difference between aspirin and all other NSAIDs
Aspirin irreversibly (!) binds to COX-1 and COX-2
MOA of Aspirin
Irreversibly binds to COX-1 and COX-2 (inhibiting PG synthesis and preventing formation of TXA2)
-Analgesic (at high doses)
-Anti-inflamm (at high doses)
Peak plasma levels of aspirin occurs when?
Is aspirin more selective to COX-1 or COX-2?
COX-1 as long as it is under 100 mg dosage
Contraindications to aspirin
-Pregnancy C/D (avoid esp in 3rd trimester)
-Children under 16 yo w/viral illness (risk of Reye's syndrome)
-Asthma, nasal polyps, recurrent sinusitis
How does aspirin (or any salicylates) toxicity present?
What is the MC used non-selective NSAID?
Ibuprofen MOA and use
-Reversibly blocks COX-1 and 2
-Used in mild to moderate pain
What is the new formulation of ibuprofen and what does it do?
-For moderate pain and used to decrease opioid dose required
Pediatric use of ibuprofen?
-Commonly for fever and pain
-5 to 10 mg/kg/dose Q6-8h
Dosing of ibuprofen
It has both an OTC dose (200-400 mg Q6-8h) and a prescription dose (600-800 mg Q6-8h)