Pain Management Flashcards
PO vs IV meds - Time to peak effect
PO peaks at 1.5 hours
IV peaks at 30 minutes
PO vs IV medications - onset of action
PO Starts 30 minutes – one hour
IV Starts 5–15 minutes
PO vs IV - duration
PO lasts 4 hours (req q4 dosing)
IV lasts 2-3 hours
How do you calculate the breakthrough dose when using extended release pain medications?
Used 10 to 15% (of 24 hour SR/ER dose) PO for breakthrough…. Divide that throughout the day
The patient is on a total daily dose of 100 mg of morphine daily. What dose of fentanyl patch would you like to switch a patient to & how long will it take for the fentanyl patch to start working?
Dose: 50 µg per hour
Onset: 18 - 24 hours to start working
Max. Tylenol/acetaminophen dosing per day in a patient with and one without liver disease?
4 g daily (w/o liver disease) or 2 g daily (with liver disease)
*preferably no Tylenol if pt has liver disease
Types of pain medications to use for mild pain (VAS 1-3)
Acetaminophen, aspirin and NSAIDs
+- benzos, TCAs, SNRIs, anti-seizure, anti-spasmodic
Strongest NSAID
Ketorolac (Toradol)
Which NSAID is strongest?
- ibuprofen
- naproxen
Ibuprofen (1:40 morphine ratio)
Naproxen has a 1:50 ration, ie req more drug to cause same effect
Drugs to use for moderate pain (VAS 4-7)
Least potent: codeine + acetaminophen (Tylenol 2,3,4)
Middle: hydrocodone + acetaminophen
(Norco, Vicodin)
*vicodin has more Tylenol so slightly less potent
Most potent: oxycodone + acetaminophen (Percosate)
Drug choices for a cancer patient with severe pain (VAS >7)
Morphine Hydrocodone Oxycodone Hydromorphone Oxymorphone Methadone Fentanyl
(In order of potency)
Two key points about methadone
1) very long acting – patient may not see full effect until a week later
2) EKG is required before starting the medication due to risk of QT prolongation (should also check for other drugs that may cause QT prolongation: antiarrhythmics, ABX, antidepressants/antipsychotics, sumatriptan)
When starting a PCA, which type patient should never have a basal rate initiated?
Most patients! Especially opioid naïve patients.
Only start a basal rate if the patient is opioid tolerant. Basal rates have not been shown to improve pain relief or sleep but do carry a risk of increased sedation and respiratory depression
Demand dose for an opioid naive patient versus elderly patient
1mg for opioid naive
0.5 for elderly (opioid requirements decrease with age)
Advantages of PCAs
More individual dosing/titration accounting for inter-and intraindividual variability
Negative feedback control (sedation prevents pushing the button)
Increased patient satisfaction with pain control
Increased analgesic efficacy
