Acute Pain - Drugs - Exam 2 Flashcards
What are long-term Opioid options? (7)
- codeine (Tylenol #3)
- fentanyl (duragesic patch)
- hydrocodone (lortab, vicodin)
- hydromorphone (dilaudid)
- methadone (dolophine)
- morphine (MSIR, MScontin, Kadian)
- oxycodone (OxyIR, Percocet, Percodan, Oxycontin)
Codeine
What is the chemical name?
What is it derived from?
It has a substitution of ____ group for ____ group on #3 carbon of morphine.
3-methyloxymorphine
- derived from opium poppy plant (papaver somniferum)
- methyl group for hydroxyl group
Codeine
Receptors:
- Mu opioid
- weak kappa/delta
Codeine
Codeine is more reliably ________ ________ than morphine.
absorbed orally
Codeine
Codeine is admin as a ________.
It is metabolized by what enzyme? (active state)
what enzyme metabolizes codeine to the inactive state?
- prodrug
- CYP2D6 = morphine (active)
- CYP3A4 = norcodeine (inactive)
Codeine
Why is there variability in analgesic effects w/ codeine?
- > 50 polymorphisms in CYP enzymes
- don’t give to children < 12y/o - they will only get the SE and no pain relief
Codeine
Adult dose:
max dose:
How much codeine does Tylenol # 3 have?
Tylenol # 4?
- 15-60 mg q4h
- max: 360mg/d (4-6 doses)
- # 3 - 30mg
- # 4 - 60mg
Codeine
Pedi dosing
max:
0.5-1mg/kg
Max: 60mg
try to avoid giving
Codeine
At what dose of codeine do you get the max analgesic effect?
What med & dose is this comparable to?
60 mg
Aspirin 650mg
Codeine
Half-life
3-3.5hrs
Codeine
Drug Interactions
- opiods
- alcohol
- anticholinergics
Codeine
Adverse/SE (8):
- n/v
- brady
- hypotension
- resp. depression (lg. doses)
- urinary retention
- constipation
- dizziness
- miosis
Codeine
Contraindications
- hypersensitivity
- acute/severe asthma (histamine release = bronchoconstriction)
- paralytic ileus
Tramadol
What is the chemical name?
- composed of a racemic mixture w/ a ____ and ____ enantiomer.
- Synthetic 4 phenylpiperidine analogue of morphine & codeine
- + and - enantiomer
Tramadol
MOA of the + enantiomer:
- centrally acting opioid agonsit
- mod. affinity @ Mu
- weak Kappa/delta
- opposes serotonin reuptake
Tramadol
MOA of the - enantiomer:
what are the effects of this?
- inhibits NE reuptake
- stimulates a2 receptors
- effects: BP issues, potentiate precedex
Tramadol
Metabolism:
active metabolite:
potency:
- CYP2D6 & CYP3A4
- O-desmethyltramadol
- 2-4x potent as tramadol (less potent than morphine)
Tramadol
Potency compared to morphine
1/5-1/10 as potent as morphine
Tramadol
Onset:
1-2 hrs
Tramadol
Half-life:
- tramadol: 6.3hrs
- metabolite: 7.4hrs
Tramadol
PB:
20%
Tramadol
Vd:
2.6-2.9L/kg
Tramadol SE/Precautions
Major Contraindication:
high incidence of:
- do NOT give in pts w/ seizure disorders
- high incidence of n/v
Morphine
Who was morphine named after?
Morpheus the Greek God of Dream
Morphine
What preparations is Morphine available in?
- immediate and sustained release
- elixir
- suspension
- tablets/capsules
- epidural/intrathecal
Morphine
Oral dose:IM/IV dose
- oral dose 3x more
- oral - 30 mg
- IV/IM - 10 mg
Morphine
Receptor Effects:
Mu 1 & Mu 2
Morphine
Metabolism:
active metabolites and effects
- conjugation (glucuronic acid) w/ hepatic & extrahepatic sites (kidneys)
- morphine-6-glucuronide: analgesia
- morphine-3-glucuronide: neurotoxicity & hyperalgesia
Morphine
What are the 3 reasons why morphine has minimal absorption into the CNS?
- poor lipid solubility
- high PB%
- high degree of ionization @ physiologic pH
Morphine
PO dose & onset:
- PO: 30-60mg
Onset: 30min - 1hr
Morphine
IV dose & onset:
- IV dose: 2.5-15mg
- IV onset: 15 min
Morphine
IM dose:
IM onset:
IM dose: 10-15 mg
IM onset: 20 min
Morphine
Peak:
Duration:
- peak: 45-90 min
- duration: 4-5 hrs
Morphine
E 1/2 time:
1.7-3.3 hours
Morphine
Does morphine have greater analgesia potency and slower offset in men or women?
Women
Morphine
% PB
Vd
- % PB - 35%
- Vd - 224L/kg
Morphine
What pt population should morphine be avoided in and why?
- renal impairment
- morphine-6-glucuronide accummulation = resp. depression