Drugs For Treating Pain Flashcards
Pain: a unpleasant _____ and _____ experience associated with or resembling that associated with actual or potential ______ damage or described in terms of such damage.
- sensory
- emotional
- tissue
What is the difference between acute and chronic pain?
- acute: up to 6 months? 6 weeks with acute injury
- chronic: 3-6+ months
Describe the 3 types of pain:
- nociceptive: pain that we can link to somatic or visceral stimulation.
- inflammatory: can stimulate pain receptors
- pathological: pain that is not from a injury source. Can be emotional or psychological component or issues in processing sensation.
Describe analgesics:
- drugs used to alleviate (reduce or eliminate) pain
- does not cause loss of consciousness
Describe opiates:
- drugs that are obtained from the opium poppy
- naturally occurring drug
- main form: morphine
Describe opioids:
- broader term referring to drugs with similar effects as opiates
- can be synthetic and semi-synthetic
Describe narcotics:
- any controlled substance in legal context
- primary categories: schedule 1 and 2. Illegal to produce, distribute, or administer.
Describe narcotic analgesic:
- another term referring to opioids
- relieves pain and produces a state of drowsiness or sleep. Can affect consciousness.
- pain relievers that have an abuse potential
Give examples of types of drugs for treating pain:
- NSAIDs and corticosteroids
- Acetaminophen (non opioid analgesics)
- opioids
- topical analgesics
- topical and local anesthetics
- caffeine
- anti-depressants and anti-convulsants
Outside of North America, Acetaminophen is called….
Paracetamol
Describe the potential therapeutic effects of acetaminophen.
- analgesic and antipyretic
- not anti-inflammatory or anti-platelet
Acetaminophen does not affect what organs/structures?
- does not cause stomach irritation or ulcers
- does not affect platelet function
- does not affect kidney function
Acetaminophen is available in what forms?
- tablets, capsules
- chewable tablets
- suppositories
- elixirs, suspensions
- IV
What is the difference between tablets, capsules, and caplets?
- capsule can be broken open, has gelatin outer component with powder or liquid inside of it.
- tablet = round
- caplet = oval or rectangle
When would you use suppositories?
If someone is vomiting a lot
What is the difference between elixirs and suspensions?
- elixirs: liquid form (syrup), contains sugar to make it more palatable.
- suspensions: liquid that has beads in it that contain the medication. Usually administered to infants.
Describe the pharmacokinetics of acetaminophen.
- generally taken orally = goes through first pass
- readily and completely absorbed from GI tract
- half-life around 2 hours. Usually taken every 4-6 hours.
- metabolized by liver and metabolites are excreted in urine.
Indications for acetaminophen:
- mild to moderate pain
- fever
Describe the dosing of acetaminophen.
- typically 325 - 500 mg.
- Tylenol arthritis has 650 mg in a extended/controlled release form. Has different dosing schedule, usually every 12 hours.
- 4000 mg max daily dose
- 1000 mg max dose at 1 time in adults.
- ceiling effect
What is the ceiling effect?
If you take more than the recommended amount, there is no additional benefit seen and you are more at risk of adverse effects.
Describe the biggest adverse effect from acetaminophen.
- hepatotoxicity (liver toxicity)
- amount of acetaminophen exceeds the ability of the liver to metabolize it completely
- toxic metabolite accumulates and reacts with components of the liver cells
- symptoms: nausea, vomiting, drowsiness, abdominal pain
- evidence of hepatotoxicity is evident 2-4 days after overdose
- people often unknowingly take products that have acetaminophen in them (combination products)
Describe drug interactions with acetaminophen.
- alcohol: increases production of toxic metabolite of acetaminophen. Chronic alcohol consumption compromises liver.
- warfarin (anti-coagulant): even though acetaminophen is not an anti-platelet drug, it can inhibit warfarin medication and increase bleeding time
Medications often mixed with acetaminophen:
- caffeine: assumed to be utilized because it speeds up metabolism of acetaminophen so that it works faster. Migraine meds have this. Caffeine itself may also have an effect on decreasing pain.
- codeine