OTC Analgesics Flashcards
What is the equivalent dose to 10mg of morphine for acetaminophen, aspirin, ibuprofen, and naproxen?
acetaminophen: 3600mg
aspirin: 3600mg
ibuprofen: 2220mg
naproxen: 1380mg
What do you mean when we say “10mg morphine equivalent dose”?
we need this amount of agent to get to the same painkilling level as 10mg of morphine
What is the max dosing of OTC NSAIDs?
ibuprofen: 1200mg
naproxen: 440mg
Does morphine plateau in pain relief?
no, pain relief increases as dose increases
At what strength does ibuprofen peak in pain relief for an individual dose?
400mg
-anything greater is along for the ride + greater risk of se
At what strength does acetaminophen peak in pain relief for an individual dose?
1000mg
At what strength does aspirin peak in pain relief for an individual dose?
1000mg
At what dose does ibuprofens anti-inflammatory mechanism truly peak?
400-800mg TID/QID
-past the max OTC dose
-thus its tough to give OTC dosing ibuprofen any credit for
being anti-inflammatory
Which OTC analgesic is probably the most convenient?
naproxen (BID)
-ibuprofen can be up to 6x/day=highly inconvenient
Are Advil Liqui-Gels any better than Advil tablets?
no
more expensive
maybe a little bit quicker by 2 minutes
tablets are fine and dissolve quick enough
True or false: at OTC doses, ibuprofen has more side effects than acetaminophen
false
What are the nuisance side effects of OTC doses of acetaminophen and ibuprofen?
nausea
abdominal pain
dyspepsia
What is something you should never mention during an OTC consult that is revolved around acetaminophen?
hepatotoxicity as a side effect
What can taking a pill with food or fluid help with?
clearing the pill from the esophagus
help reduce some local damage to stomach
What will taking ibuprofen or acetaminophen with food NOT do?
will not prevent GI damage via systemic PG inhibition
food can also delay onset of action
True or false: NSAIDs should be taken with food
false
although its totally fine to take with food
What does the balancing the use of medicine depend on?
risk vs benefit
-dont be the side effect kings
Which agent is safer at overdose levels, acetaminophen or ibuprofen?
ibuprofen
What do products that are advertised as “pain at night” often contain, alongside one of naproxen, acetaminophen, or ibuprofen?
diphenhydramine
or methocarbamol (muscle relaxant)
What does insomnia often go hand-in-hand with?
pain
What are the most common causes of pain we will see in pharmacy?
muscle/back/joint
headache/migraine
cold/flu
What are doctors often looking for in a child before giving a medicine for pain?
behavioural signs such as facial expression, crying, irritability, poor feeding, sleep disturbance and inactivity
What is used to treat pain in children?
acetaminophen
ibuprofen
What are the OTC options for headaches and migraines?
NSAID or acetaminophen
(also triptans for migraines)
What are some differences between headaches and migraines?
headaches:
-pain around forehead
-mild, dull pressure
-incidental, non-recurring
migraines:
-pain on sides of head
-intense, pulsing or throbbing
-commonly recurring
What used to be the DOC for osteoarthritis?
acetaminophen
-Jeff says you can try for 2 weeks, no relief–>NSAID
What is the DOC for dysmenorrhea?
NSAIDs
What is dysmenorrhea?
menstrual cramps
caused by contractions in the uterus due to PGs
can start 1-2 days before period and last 2-4 days
What is the most commonly reported menstrual disorder?
dysmenorrhea
True or false: caffeine is not needed for dysmenorrhea
true
What is the issue with the Advil Plus Acetaminophen product?
the doses are not therapeutic
At what dose does caffeine have some value for headaches? What about migraines?
130mg
>100mg
-enhances efficacy of analgesics in headaches and migraines
What is medication overuse headaches?
the overuse of acute pain-relief medicine ends up causing headaches
Which analgesic combo is more likely to induce MOH?
those containing caffeine
How many days per month can caffeine-containing analgesics be used? Why?
no more than 9 days per month (JT says 15 days)
due to the potential of MOH
reserve them for 2nd line for TTH
True or false: the MOH type phenomenon is also seen when taking pain relievers for arthritis or back pain
false
Which country is the #1 biggest user of codeine?
Canada
True or false: codeine products with ASA are still used
false
codeine-ASA products no longer exist
What is codeine a prodrug for?
morphine
Which enzyme metabolizes codeine to morphine?
2D6
What is the issue with codeine as an analgesic?
depending on genetics, people metabolize codeine to different extents
thus, each person varies with how much morphine they make
What is needed before you can sell an exempted codeine product?
special training
If someone calls you and says “my kid got into ….” which drugs do you not want to hear them say?
ASA
acetaminophen
True or false: acetaminophen toxicity is a medical emergency
true
What is the amount of acetaminophen that causes hepatic toxicity in adults/adolescents?
7.5-10g in <8hr
24 regular/15 extra strength
At what dose of acetaminophen are fatalities rare in adults/adolescents?
<15g
45 regular/30 extra strength
What is the therapeutic dose of acetaminophen in pediatrics?
10-15mg/kg/d
max 75mg/kg/d
At what dose of acetaminophen are there overdose concerns in pediatrics?
150-200mg/kg
What is the max daily dosing of acetaminophen in the USA?
3000mg
-they are concerned about people not knowing
acetaminophen is present in other products
What is the max dosing of acetaminophen per day in adults?
4g
What do the vast majority of people who overdose on ibuprofen experience?
no symptoms to mild symptoms
safe drug in overdose
still get to the hospital
True or false: ibuprofen is commonly fatal from overdose
false
What do NSAIDs do to a drug like warfarin which is bound to plasma proteins?
NSAIDs bounce the drug off the protein
=more free drug
True or false: acetaminophen does not bounce drugs off of plasma proteins
true
Has the safety profile of acetaminophen changed while taking warfarin?
yes, the mechanism of interaction is unknown
more frequent monitoring is suggested
What are the doses of acetaminophen we need to worry about for someone taking warfarin?
> 2.25g per week starting point for concern
2.5g per week could be impactful
Which drugs should be avoided while on a DOAC?
NSAIDs
-increases risk of GI bleed which can be exacerbated by
DOAC
What is the mechanism of a child getting asthma via acetaminophen?
acetaminophen reduces the bodys level of a natural free scavenger (glutathione)
exposure during pregnancy or early infancy
True or false: acetaminophen during pregnancy has been associated with development of ADHD and asthma in offspring
true
If you have asthma, but arent ____, you should be able to take ibuprofen. If you have ____, ibuprofen can trigger symptoms of asthma.
aspirin-sensitive
aspirin-sensitive asthma
What are the chances of the general population having an aspirin allergy? What about people with allergies, asthma, and urticaria?
1-2%
10-30%
If someone has an ASA allergy, what are the odds of them having an ibuprofen or naproxen allergy?
ibuprofen: cross-sensitivity with ASA is 98%
naproxen: cross-sensitivity with ASA is 100%
If someone has an ASA allergy, which agents should also not be used?
ibuprofen and naproxen=higher risk of asthma exacerbations
-if the person is not ASA-sensitive, these agents can be used
When is ASA-induced asthma usually seen?
adulthood
If an elderly person comes in and asks “where is your Advil?”, what should be one of the first things that comes to mind?
are they on ASA???
What does the balance look like for ASA use?
preventing a heart attack vs risk of GI bleed
What is going on in the body when only ASA is in the blood?
cardio-proection
-ASA binds to COX-1 on platelets
-platelets are less sticky
What is going on in the body when ASA and ibuprofen are both present in the blood?
ibuprofen can hit the COX-1 receptor before ASA
-benefit of ASA is now neutralized
-no cardio-protection
increased risk of GI issues with regular use of any NSAID+ASA
If you want to avoid the ASA-ibuprofen interaction, what would this look like?
take ibuprofen 2 hours after ASA
OR
take ibuprofen 8 hours before ASA
MULTIPLE DAILY DOSES WILL BE A PROBLEM
Does naproxen interact with ASA to the same degree as ibuprofen?
less likely to interact, but still some evidence
avoid if regular use is planned
Can ASA be taken with ASA?
low potential option but GI risk increases
cant interact with itself on the platelet
-getting CV protection and relief from x
Does Voltaren have an interaction with ASA?
no
-topical
-first choice for people on ASA
True or false: Voltaren is to be used for headaches and not for joint pain
false
not headaches, used for joint pain
True or false: many analgesics have been shown to be absolutely contraindicated during pregnancy
false
What category does acetaminophen fall under in pregnancy?
category B
-commonly used in all stages
-appears to be no risk at standard doses
Flow to the lungs is not needed in a fetal heart, what is the structure on the fetal heart that allows the mother to pass oxygen to the fetus? What happens to this structure when the fetus is born?
patent ductus arteriosus
closes at birth, blood now shunts to baby’s lungs
What maintains the opening of the ductus arteriorus until birth?
prostaglandins
What category does ibuprofen fall under in pregnancy?
category C up to 30 weeks
-reasonably safe up to week 30
category D >30 weeks
-premature closing of ductus arteriosus and increased risk of
bleeding
Which category does naproxen fall under in pregnancy?
category C
avoid late in pregnancy because of PDA closure=category D
risk in 1st trimester too (spontaneous abortion)
Which category does ASA fall under in pregnancy?
category C
category D in 3rd trimester
What are the normal impacts of COX-1 on the body?
helps protect GI
negative impact on cardiovascular system
What are the normal impacts of COX-2 on the body?
causes inflammation
positive cardiovascular impact
Which agents are commonly found in combination products of NSAIDs for long term usage?
PPIs
-help GI protection that is lost by using NSAID
True or false: ibuprofen and naproxen will block both COX-1 and COX-2 to varying degrees
true
blocking the negative impact on CV (COX-1) and inflammation (COX-2)
also blocking the positive impacts on GI (COX-1) and CV (COX-2)
In general, we say ibuprofen is safer for ____ and naproxen is safer for ___.
ibu safer for GI
naproxen safer for CV
What are the drug interactions associated with NSAIDs?
drugs that negatively affect GI (steroids): increase GI risk
anticoagulants: increase bleeding risk
blood pressure meds: increase CV risk
SSRIs: increase GI risk
ASA 81mg: increase GI risk
alcohol: increase GI risk
True or false: acetaminophen should absolutely be avoid for a hangover
false
Explain the interaction between alcohol and acetaminophen.
acet normally conjugated to nontoxic conjugated metabolites or can be metabolized to a toxic metabolite NAPQ by P450, but this is normally fixed by glutathione
chronic alcohol induces P450 and depletes glutathione, thus we get a buildup of NAPQ
What is the reality of using acetaminophen for someone with cirrhosis like an alcoholic?
patients with cirrhosis have lower clearance of acet
use <2g per day, including those who continue to drink
What is the verdict on acute alcohol ingestion and acetaminophen?
not a risk factor for hepatotoxicity
may even be protective by competing for CYP2E1
What are the issues with NSAIDs and the eldery?
decreased renal
more medicines
more conditions
more bleed risk
more CV issues
=big concern for the elderly to be taking an NSAID
When might NSAIDs be an issue with sports?
dehydration
-PGs help kidney perfusion, NSAIDs block this
True or false: NSAIDs have reliable effects on acute injury swelling
false
could affect the healing and re-modelling
What is the only reliable way to treat MOH?
stop the headache medicine
What is the usual dosage of codeine for adults?
15-60mg q4h prn
max 360mg q24h
Do enteric coatings of NSAIDs prevent stomach bleeding?
no, just as likely to cause stomach bleed (rare in the first place)
its the systemic effect that causes stomach bleeding
How should NSAIDs be taken for acute pain when a rapid onset of effect is desired?
empty stomach with a full glass of water
FOOD DELAYS AND MAY REDUCE ANALGESIC EFFECT
True or false: there is a risk of GI bleed when alcohol is taken with an NSAID
true
What are the rates of nausea, abdominal pain, and heartburn for ibuprofen? What about acetaminophen?
ibuprofen:
-nausea: 6.3%
-abdominal pain: 2.7%
-dyspepsia: 5.4%
acetaminophen:
-nausea: 4.5%
-abdominal pain: 5.4%
-dyspepsia: 0.9%
