Flashcards in Fentanyl Deck (32)
What is the drug class of Fentanyl?
synthetic phenylpiperidine opioid agonist, analgesic
What are the uses of Fentanyl?
-Analgesia intraop and postop
-administered as premed to blunt hemodynamic responses to airway manipulation and reduce inhalation agent dosage requirements
-provides GA either administered as sole anesthetic or in combo with IV sedatives/hypnotics
-administered in the epidural and subarachnoid spaces to augment the effectiveness of RA
What is the MOA of Fentanyl?
-Binds to mu opioid receptors in the brain, brainstem, spinal cord, and primary afferent peripheral terminals producing analgesia
-mimics the actions of enkephalins, endorphins, dynorphins causing the action of antinocioceptive systems resulting in cellular hyperpolarization and inhibition of NT release
How is Fentanyl metabolized?
primarily in the liver by N-dealkylation and Hydroxylation
-dependent on liver blood flow/ high hepatic extraction ratio
Does metabolism of Fentanyl produce metabolites?
-minimally pharmacologically active metabolites: Norfentanil, hydroxyproprionyl-fentanyl, and hydroxyproprionyl-norfentanyl
How is Fentanyl redistributed?
-Fentanyl is highly lipid soluble allowing rapid crossing of biological membranes and uptake by highly perfused tissue groups including the brain, heart, lungs
-Rapidly redistributed to inactive tissue sites such as fat and muscle
What is important about the lungs and Fentanyl?
The lungs serve as a large inactive storage site, with an estimated 75% of the initial dose undergoing 1st pass pulmonary uptake
What is the Volume of Distribution?
Vd is 4L/kg
What is the distribution time? redistribution time?
Distrib time: 1.7 minutes
Redistribution time: 13 minutes
What is the termination elimination 1/2 time of Fentanyl?
3.1 - 6.6 hours
How is Fentanyl eliminated?
Norfentanyl (principle metabolite) excreted by the kidneys and can be detected in the urine 48 - 72 hours after administration
Is Fentanyl protein bound?
approx 80% protein bound to plasma proteins
What are the CNS side effects of Fentanyl?
-increase in ICP in head injury patients if respiration is not controlled
-seizure like activity and muscle rigidity
-Dizziness, blurred vision
-Drowsiness, Sedation, Confusion
What are the CV effects of Fentanyl?
-Elevated CVP, PAP, and PVR associated with opioid induced muscle rigidity, hypotension, peripheral vasodilation, arrythmia
What are the respiratory effects of Fentanyl?
-depression of airway reflexes
-decreased lung compliance, FRC, hypercapnia, and hypoxemia associated with opioid induced muscle rigidity
What are the GI effects of Fentanyl?
-increased common bile duct pressure
-Delayed gastric emptying and intestinal transit
What are the endocrine/metabolic effects of Fentanyl?
What are the contraindications to use of Fentanyl?
-use with caution in patients with impaired hepatic and/or renal function, head trauma, elevated ICP, and bradyarrhythmias
What synergistic effect occurs with Fentanyl and ____________ and __________?
Benzodiazepines and other CNS depressants cause marked opioid synergism with respect to hypnosis and respiratory depression
What drug interaction can occur between Fentanyl and Nitrous Oxide?
Adminstration with _________ and Fentanyl may cause?
may cause hypotension or HTN
What is the anesthetic premedication dose of Fentanyl?
25 - 100 mcg
What is the analgesia (including post-op bolus) dose of Fentanyl?
1 - 2 mcg/kg (usually 0.5-1 mcg/kg)
What is the infusion dose of Fentanyl?
0.01 - 0.05 mcg/kg/min
What is the GA IV dose for a sole agent, for Fentanyl?
50 - 150 mcg/kg
What is the regional anesthesia dose for Fentanyl?
Epidural: 50 - 100 mcg (loading)
Spinal: 10 - 25 mcg
What is the reversal/ antagonist of Fentanyl and the dose of it?
Naloxone (Narcan) at 0.1 - 2 mg IV incremental doses; 10 mg max
Is Fentanyl more or less lipid soluble than morphine with a longer or shorter DOA?
MORE lipid soluble than Morphine with SHORTER DOA- 75% of initial dose undergoing first pass pulmonary uptake
_______ redistribution to _________ tissue sites as ______, _________ _________, and ________
rapid redistribution to inactive tissue sites as fat, skeletal muscle, and lungs