Opioids Flashcards
Mu 1
Supraspinal and spinal Analgesia - Main action Euphoria N/V, Pruritis Low Abuse Potential Bradycardia Endorphins, morphine, synthetic opioids
Mu 2
Spinal Hypoventilation Analgesia Euphoria, sedation Physical Dependence Constipation Endorphins, morphine, synthetic opioids
Kappa
Supraspinal, Spinal Analgesia Respiratory Depression <Mu Dysphoria, Diuresis Dynorphins Agonist-antagonists principally work here Resistant to high intensity pain Nabuphine (agonist at kappa, antagonist at mu)
Delta
Supraspinal, spinal Analgesia Respiratory Depression Physical Dependence Urinary Retention Enkephalins
Neuraxial Opioids
Pruritis
N/V
Urinary Retention
Ventilatory Depression
Opioid Cardiovascular Side Effects
Decrease Sympathetic Tone
Decrease Blood Pressure
Decrease Heart Rate
Meperidine (demerol) has antimuscarinic effects similar to atropine
Opioid Respiratory Effects
Respiratory Depression Increased PaCO2 Decreased Respiratory Rate Increased Tidal Volume Decreased Minute Ventilation Cough Suppression
Opioid CNS Effects
Sedation and analgesia
Reduces MAC
Decreased Cerebral Blood flow and metabolic rate
Increased ICP with hypoventilation
Seizures with meperedine use due to normeperedine accumulation
Morphine (IV/IM)
Potency 1
Onset 15-30 minutes
2-10 mg
Peak effect 45-90 minutes
Duration 3-4 hours
Metabolized via conjugation with glucuronic acid in hepatic, extrahepatic, and the kidneys
Morphine 6-glucaronide is active metabolite built up in kidney disease.
Meperidine (demerol) (IV/IM/PO)
0.1 Potency of morphine Peak effect 5-7 minutes Duration 2-4 hours Local/atropine like side effects (block sodium channels, tachycardia, dry mouth, mydriasis) 90% hepatic metabolism to normeperidine Treatment for post-op shivering
Fentanyl (IV, Transdermal, PO, intranasal)
75-125 x more potent than morphine Peak effect 3-5 minutes Duration 30-60 minutes 75% undergoes 1st pass pulmonary uptake Highly lipid soluble and protein bound hemodynamic stability drug interactions Induction 2-6 mcg/kg Maintenance: 25-50mcg 15-30 minutes or 0.5-5 mcg/kg/hr
Sufentanil
5-10x as potent as fentanyl Greater affinity for opioid receptor Peak 3-5 minutes Duration 30-60 minutes 0.3-1 mcg/kg 1-3 minutes b4 DL 0.5 mcg/kg followed by 0.5mcg/kg/hr
Alfentanyl
1/5 to 1/10 as potent as fentanyl Duration 10-20 minutes Peak effect 1.5-2 minutes Renal failure doesn't alter clearance Rapid on/off Good for RBB, DL 5-10 mcg/kg
Remifentanyl
Similar potency to fentanyl
Peak effect 1.5-2 minutes
Duration 6-12 minutes
Metabolized by plasma and tissue esterases
Good for RBB, continuous gtt, MAC vs general
Quick recovery cases
0.5-1mcg/kg for DL then 0.25-0.5mcg/kg/min
Codeine
Antitussive, analgesia for mild to moderate pain
