Module 8 Flashcards
Nociceptors
Nerve endings that selectively respond to painful stimuli and send pain signals to the brain and spinal cord
Antiprostaglandin
Drug that inhibits the synthesis of prostaglandins
Antipyretic
Drug that has the ability to lower body temperature
Arachidonic acid
phospholipid released in the cell membrane in response to cellular injury
Cyclooxygenase
Enzyme that produces prostaglandins from arachidonic acids
Non-steroidal anti-inflammatory drug
medication that inhibits the synthesis of prostaglandins; used to prevent and treat mild to moderate pain and inflammation
Prostaglandin
Chemical mediator found in most body tissues; helps regulate many cell functions and participate in the inflammatory response as well as initiate uterine contractions in labor
pyrogens
Fever-producing agent
Reye’s syndrome
potentially fatal disease characterized by encephalopathy and fatty liver accumulations; associated with the use of aspirin and NSAIDS after viral infections such as chickenpox or influenza in children and adolescents
characteristics: encephalopathy, hepatic damage, other serious problems
Salicylism
toxic effects of a salicylate drug; may occur with an acute overdose or with chronic use of therapeutic doses, especially the higher doses taken for anti-inflammatory effects
Somatic pain
simulation of nociceptors in the skin, bone, muscle and soft tissue such as sprains (well localized)
somatic pain description
described as sharp, burning, gnawing, throbbing, or cramping
low moderate intensity may stimulate the sympathetic nervous system
Visceral pain
nociceptors stimulated in abdomen, thoracic organs and surrounding tissues such as pancreatitis, cholecystitis (diffused, not well localized)
Visceral pain described as
deep, dull, aching, or cramping
severe visceral pain stimulates the parasympathetic nervous system
Neuropathic pain
caused by lesions of physiologic changes that injure peripheral pain receptors, nerves, or CNS (common cause of chronic pain)
Neuropathic pain is described as
Usually described as severe, shooting, burning, or stabbing
usually with:
diabetes mellitus
herpes zoster infections
traumatic nerve injuries
some types of cancer or cancer treatments
Duration of pain
acute: results from injury, trauma, spasm, disease processes, diagnostic procedures, or surgeries that damage body tissues
chronic: last 3 months or longer, and related to chronic disease
Mechanical pain
occurs when stress is placed on a joint or soft tissue, such as when you bend your finger all the way back or stretch your calf
-when you have pain that comes and goes or changes with different movements and or positions it is mechanical
Chemical pain
caused by the body’s inflammatory response to injury. An example of chemical pain would be hitting your thumb with a hammer or a toothache
chemical pain is described as throbbing, constant and does not change with movement
Prostaglandins effect in stomach
decrease gastric acid secretion, increase mucous secretion, and regulate blood circulation
Prostaglandins effect in the kidneys
maintain adequate blood flow and function
Prostaglandins effect in cardiovascular system
help regulate vascular tone and platelet function
prostaglandins effect on bronchioles
dilates bronchioles
Cox-1 enzyme
enzymes are continuously in all tissues, not just at the time of inflammation. They secrete a cytoprotective mucus
Cox-2 enzyme
Normally present in several tissues (brain, bone, kidneys, GI, femal reproductive system). Is usually present in a small amount and usually inactive until simulated by pain and inflammation. Induced by interlukin-1 and TNF-alpha, H-pylori. Overall prostaglandins produced by COX-2 are associated w/ pain and other signs of inflammation
Fever
elevation in body temp which is controlled by the hypothalamus
hypothalamus responds to pyrogens and resets the body temp to a higher set point
this temp is regulated and mediated by prostaglandins
mechanisms that cause the increased body temp include vasoconstriction that shunts blood to the core, and shivering
NSAID Examples
ibuprofen
Aspirin (also a salicylate)
Celebrex
NSAID indications
inflammatory disorders
-degenerative joint disease, osteoarthritis, RA, bursitis
To reduce fever
-blocks prostaglandins
-ASA not to be used in children due to risk of Reye’s syndrome
To relieve pain
MOA of Ibuprofen
Blocking of COX enzymes
These drugs are classified into two types or generations. First generation NSAIDs block both COX-1 and COX-2 and second generation NSAIDS block only COX-2
Adverse effects of ibuprofen
Related to blocking of both enzymes and changes in the functions they influence
nausea, dyspepsia, constipation, epigastric pain
GI bleed with COX-1
HTN (caused by varying effects of prostaglandins)
Nephrotoxicity increased BUN and creatinine, Edema
respiratory- dyspnea, bronchospasm, pharyngitis
Drug on Drug interactions with ibuprofen
Anticoagulants- increase the risk of bleeding
Codeine, Oxycodone, and hydrocodone- have an additive analgesic effect
Corticosteroids- have additive gastric irritant and possible ulcerogenic effects
Glucocorticoids and alcohol increase the risk of GI bleed
Contraindications for ibuprofen
Increase risk of serious GI adverse events
-bleeding
-ulceration
-perforation of stomach and intestines
Contraindicated by the presence of
-peptic ulcer disease
-GI or other bleeding disorders
-impaired renal function
General info of NSAIDS
advise client to stop aspirin 1 week prior to any elective surgery
advise client to take NSAIDS with food or milk (reduce stomach discomfort)
Concurrent use with opioids allows for lower dosage of opioids (minimize effects such as constipation, respiratory depression)
Toradol is used for short-term treatment of moderate to sever pain associated with post op surgery - only given IV, IM (liquid ibuprofen)
Salicylates (Aspirin)
Aspirin is an NSAID
has anti inflammatory properties
antipyretic properties
analgesia properties
* Suppresses platelet aggregation (antiplatelet) *
Indication for Aspirin
-Reduces Fever
-suppress platelet aggregation
-effective in treating mild to moderate pain (HA, minor trauma, minor surgery)
Adverse effects of aspirin
GI- blood loss, petechia, and bruising
reyes syndrome
Toxicity of Aspirin
salicylism
-toxic effects of a salicylate drug
-may occur with an acute overdose or with chronic use of therapeutic doses, especially the higher doses taken for anti-inflammatory effects
-toxicity occurs at levels above 300 mcg/ml
-effects include hyperventilation, confusion, seizures, and coma
Aspirin Contraindicated by
presence of peptic ulcers and bleeding disorders
impaired renal function
alcohol abuse, presence of viral infections
avoid in pregnancy
Acetaminophen indications
-fever
-pain- other used as a replacement for aspirin in pain treatment because it does not cause nausea, vomiting, or GI bleeding and it does not interfere with blood clotting. Lacks anti-inflammatory activity
MOA of acetaminophen
Fever: acts directly on the hypothalamus to increase vasodilation and sweating
Pain: unknown mechanism of action
Pharmacokinetics of acetaminophen
metabolized in the liver; small amount remains in the body as toxic metabolite
adverse effects of acetaminophen
hepatotoxicity is the most common adverse effect of acetaminophen
Toxicity of acetaminophen
prevention: maximum daily dose is 4g from all sources
overdose causes hepatotoxicity
metabolism of acetaminophen produces a toxic metabolite that is normally inactivated by combining with glutathione. When glutathione is depleted, the metabolite can cause damage
overdose may be accidental or intentional
signs/symptoms are nonspecific
24-48 hours after overdose, liver function test begin to show increased levels
later manifestations may include jaundice, vomiting, CNS stimulation with excitement, and delirium followed by coma and death
treatment for acetaminophen toxicity
Gastric lavage and activated charcoal
-if overdose detected within 4 hours after ingestion
antidote: acetylcysteine
-oral or IV
-most beneficial if given 8-10 hours after ingestion, may be helpful within 36 hours
-does not reverse damage already sustained
contraindications of acetaminophen
know hypersensitivity
caution with administration in impaired hepatic and renal function
