Opioid Drugs Flashcards
Fentanyl Dosing
Induction dose as adjunct: 1 – 3 mcg/kg
Infusion: 0.01 – 0.05 mcg/kg/min
Small dose boluses: 25 – 50 mcg
Fentanyl IV Onset, Peak, and DOA
Onset: 2 min
Peak effect: 20 min
DOA: 30 min
Fentanyl Redistribution
Extensive uptake in lungs and red blood cells
Fentanyl Metabolism
Hepatic metabolism to inactive metabolite norfentanyl
Fentanyl Excretion
Eliminated in feces and urine
Fentanyl Respiratory Effects
Pulmonary first pass can cause coughing
Fentanyl Transdermal Patch (2)
Once applied, it takes 11 hours for peak effect
Once removed, it takes 18 hours for plasma concentration to decrease by half
Meperidine Dosing
Intravenous small dose boluses: 12.5 – 25 mg
Meperidine Onset, Peak, DOA
Onset: 5 minutes
Peak effect: 30 minutes
DOA: 2 hours
Meperidine Metabolism
Hepatic metabolism via CYP system to normeperidine
Meperidine Active Metabolite Considerations (5)
Normeperidine
½ the analgesic & ½ life significantly longer than meperidine
Lowers seizure threshold, induces CNS excitability
Accumulation causes CNS excitation
Tremors, muscle twitches, seizures
Risk with renal failure, high dose chronic use
Meperidine Excretion
Eliminated by the kidneys
Meperidine Special Considerations (5)
Structurally like atropine and may cause tachycardia
Demonstrates similarities to local anesthetics when administered intrathecally
Significant drug interaction with MAO inhibitors
Effective in decrease postoperative shivering, because of meperidine’s effects at the Kappa receptor
Meperidine (and morphine) can cause histamine related bronchospasm
Hydromorphone Dosing
Intravenous small dose boluses: 0.2 mg
Hydromorphone Onset, Peak, DOA
Onset: 15 minutes
Peak effect: 30 minutes
DOA: 4 hours
Hydromorphone Metabolism
Hepatic metabolism via CYP system to hydromorphine-3-glucuronide (inactive)
Hydromorphone Excretion
Eliminated by the kidneys
Remifentanil Induction and Infusion Dosing
Intravenous induction dose: 2 mcg/kg
Intravenous infusion: 0.05 mcg/kg/min
Remifentanil Risk During Administration
R/f opioid induced muscle rigidity
Remifentanil Onset, Peak, DOA
Onset: 1 minutes
Peak effect: 1 minute
DOA: 5 minutes
Remifentanil Metabolism
Ester hydrolysis via blood and tissue esterases
Remifentanil Excretion
Eliminated by the kidneys
Remifentanil CV Effects
Induction doses of reminfentanil may cause profound bradycardia and are often administered with ephedrine
Remifentanil Pain Implications
May contribute to post-operative hyperalgesia, therefor the CRNA should create a plan for postoperative analgesia
Remifentanil Metabolism Considerations
Remifentanil’s metabolism by plasma esterases (not pseudocholinesterases) lend itself well to patients with renal and/or liver failure
Remifentanil’s rapid onset, short DOA and titratability lend itself well to an intraoperative infusion
Naloxone Class
Class: nonselective opioid antagonist
Naloxone Uses
Reverses opioid induced respiratory depression, analgesia, sedation, nausea, puritis and constipation
Naloxone Dose
Dose: 40 mcg boluses (titrate slowly)
Naloxone Onset and DOA
Onset: 1 minutes | DOA: 30 minutes (shorter than most opioids)
Rebound sedation
Naloxone Side Effects
Side effects: pulmonary edema, tachycardia, hypertension
