Opioids Flashcards
Fentanyl induction dose, onset, peak, duration?
dose: 2 - 20 mcg/kg induction as adjunct to Volatile Anesthetic, 50 - 150 mcg/kg induction alone for cardiac surgery
onset: 30 seconds
peak: 5 - 15 minutes
duration: 30 - 60 minutes
Sufentanil induction dose, onset, peak, duration?
dose: 0.6 - 4 mcg/kg
onset: 1 - 3 minutes
peak: 3 - 5 minutes
duration: 20 - 45 minutes
Alfentanil induction dose, onset, peak, duration?
dose: 8 - 100 mcg/kg induction dose, 0.5 - 3 mcg/kg/min infusion dose
onset: 1 - 2 minutes
peak: 1 - 2 minutes
duration: 10 - 15 minutes
Meperidine dose - intraop
2.5 - 5 mg/kg IV
Meperidine dose, onset, peak, duration?
dose: 0.5 - 2 mg/kg
onset: 30 - 60 seconds
peak: 5 - 15 minutes
duration: 2 - 4 hours
Morphine induction dose, onset, peak, duration?
dose: 0.1 - 1 mg/kg
onset: 5 - 10 minutes
peak: 15 minutes
duration: 2 - 4 hours
Ketorlac IV dose, onset, peak, duration?
dose: 30 mg
onset: 10 minutes
peak: 1 - 2 hours
duration: 4 - 6 hours
Dilaudid dose, onset, peak, duration.
dose: 0.01 - 0.04 mg/kg IV
Morphine is metabolized primarily by what?
hepatic phase II conjugation
Does morphine cause a histamine release?
yes
Morphine, sufentanil, and fentanyl are agonists to which receptor? Causing what?
mu-opioid receptor
causes:
(1) an inhibition of adenylyl cyclase, leading to a decrease in calcium influx to cytoplasm and out from sarcoplasmic reticulum
(2) inhibition of conductance of presynaptic voltage-gated calcium channels
(3) opens inward rectifying potassium channels, hyperpolarizing post-synaptic neurons
Fentanyl:Morphine conversion
100:1 (x100)
Effects of morphine on the pulmonary and cardiac system.
Pulmonary - decreased cough reflex, bronchodilation (d/t histamine release), decreased ventilatory drive
Cardiac - decreased HR, decreased MAP (d/t histamine release), decreased CBF
Effects of sufentanil (Sufenta) on the pulmonary and cardiac system.
Pulmonary - respiratory depression (potentiated by volatile anesthetic agents), may cause “tight-chest”
Cardiac - hemodynamically stable
How is sufentanil (Sufenta) metabolized?
hepatic elimination
Effects of fentanyl (Sublimaze) on the pulmonary and cardiac system.
Pulmonary - blunts broncho-constrictive response to stimulation, possible “tight-chest”, decreased ventilatory drive, no broncho-dilation
Cardiac - vagally mediated decreases in HR, venodilation, decrease in CV sympathetic reflexes, decreased MAP and CBF
Receptor for dynorphins
Kappa
How is fentanyl (Sublimaze) metabolized?
hepatic and pulmonary elimination
What is ketorolac’s mechanism of action?
inhibition of cyclooxygenase, leading to decreased prostaglandin synthesis
How is ketorolac (Toradol) metabolized and eliminated?
hepatic metabolism
renal elimination
What are the principal effects of opioid receptor activation?
a decrease in neurotransmission(intracellularly - increased K conductance [leads to hyperpolarization], calcium channel inactivation, or both)
Contraindications to using ketorolac (Toradol).
- may prolong bleeding time (ie. ulcers)
- parturients (decreases uterine contractility and fetal circulation)
- CVA
- asthma (may cause bronchospasm)
- CHF
- advanced renal impairment (inhibiting the release of vasoactive substances in CHF and renal failure may cause renal arteriolar constriction)
- interferes with osteoblasts (not good for ortho surgeries)
How is meperidine (Demerol) metabolized, what is the name of its metabolite, and what can that metabolite cause? How is meperidine excreted?
- hepatic
- normeperidine
- lowering of seizure threshold
- excreted through the urine
Contraindications to using meperidine (Demerol).
- seizures
- MAOI
- incompatible with barbiturates
- crosses placenta
What is produced by activation of kappa receptors?
analgesia, dysphoria, sedation, diuresis, and miosis
Contraindications to using meperidine (Demerol).
- seizures
- MAOI
- incompatible with barbiturates
- crosses placenta
How is alfentanil (Alfental) eliminated?
renal
Dilaudid:Morphine conversion
10:1 (x10)
Ketorolac dose, onset, peak, duration.
dose: 30 mg IVonset: 10 minpeak: 2 - 3 hoursduration: 6 - 8 hours
Mepiridine:Morphine conversion
1:10 (x0.1)
Alfentanil dose - intraop
8 - 100 mcg/kg IV (loading dose)0.5 - 3 mcg/kg/min (maintenance)
Sufentanil:Morphine conversion
1000:1 (x1000)
Receptor for endorphins
Mu1 and Mu2
Receptor for enkephalins
Delta
Opioids are unique in producing what, without loss of what?
produce analgesia without loss of touch, proprioception, or consciousness
Are opioids agonists or antagonists?
agonists at opioid receptor sites in the CNS (brainstem and spinal cord) and outside the CNS in peripheral tissues
What is produced by activation of mu1 receptors?
analgesia, bradycardia, hypothermia, urinary retention
What is produced by activation of mu2 receptors?
hypoventilation, bradycardia, constipation, and physical dependence
What is produced by activation of the delta receptors?
analgesia, respiratory depression, physical dependence, constipation, and urinary retention
How is remifentanil different from other narcotics?
metabolized by plasma esterases, thus resulting in a context-sensitive half-time that is independent of the duration of its infusion.
Naloxone (Narcan) dose, onset, peak, duration?
dose: 0.4 - 2 mg titrate to effect
onset: 1 - 2 minutes
peak: 5 - 15 minutes
duration: 1 - 2 hours
Naloxone (Narcan) mechanism of action.
- non-selective opioid antagonist that displaces opioids from mu receptors
- has a high receptor affinity.
- prevents receptor activity
How is narcan metabolized and eliminated?
hepatic metabolism
renal elimination
Can narcan be used for patients in a shock state?
yes. a dose of 0.4 - 1.2 mg can increase cardiac output and MAP. (for knowledge!)
