Opioid Agonist (Exam 2) *Quick Review* Flashcards
Hydromorphone: Potency
5x more potent than morphine
Alfentanil: Potency
1/5th potency of fentanyl
Fentanyl: Potency
75 to 125 x more potent than morphine
Remifentanil: Potency
15-20 x as potent as alfentanil
..Not sure about Fentanyl?..
Sufentanil: Potency
5-12 x more potent than Fentanyl
Meperidine: Potency
1/10th potency of morphine
Meperidine: Clinical Uses
-Post op shivering because of K and a2 receptors
Meperidine: Dose
post op shivering 12.5 mg IV
Meperidine: Onset
5-15 mins
Meperidine: Duration
2-4 hours
Meperidine: Metabolism
-90% in Liver
-Metabolite: Normeperidine
Meperidine: E 1/2 Time
3-5 hrs
35 hrs with Renal failure
Meperidine: Clearance
1.02 L/min
Meperidine: CNS
-Sedation,
-Euphoria
-SEROTONIN SYNDROME – careful with TCA’s and MAOI’s
Meperidine: Other Side Effects
-TOXICITY: Delirium (confusion and hallucinations, myoclonus and seizures)
-CROSSES PLACENTAL BARRIER!
Morphine:Clinical uses
- Relieves visceral, skeletal muscles, joints
- Integumental dull > sharp (better for post op c-fiber pain)
- Intermittent pain
Morphine: Dose (induction)
Intra Op: 1-10 mg IV
Morphine: Onset
10 - 20 mins
Morphine: Peak (IM & IV)
IM: 45-90
IV: 15-30 minutes
Morphine: Duration
4-5 hours
Morphine: Metabolism
- Glucoronic acid conjugation
-Morphine -3 glucorinide (75-95%) INACTIVE -Morphine -6-glucoride: ACTIVE
-Causes the late ventilatory depression
Morphine: E 1/2 Time
1.5-3.5 hrs
Morphine: Clinical Consideration
- Caution with use in renal and elderly patients.
-Metabolites stick around longer in renal patients
- Serum plasma concentrations increase with age.
-Women > men: analgesic potency and slower speed of offset
Hydromorphone: Dose (induction)
Intra Op: 1-4 mg
**Give 0.5 mg intermittently!
HAVE TO REDOSE Q 4 HOURS
Hydromorphone: Onset
5 - 15 mins.
Hydromorphone: Duration
2 - 4 hours
Hydromorphone: Metabolism
Has active metabolites!
Hydromorphone: Special consideration (Hint: gives it an edge on morphine)
No histamine release
Remember this is an issue with Morphine that we dont like
Alfentanil: Induction dose
-Induction Laryngoscopy: 15-30 µg/kg IV
**give 90 sec prior
-Induction alone: 150-300 µg/kg IV
Alfentanil: Maintenance Dose
25-150 µg/kg/hour w/ inhaled gas
Alfentanil : Onset
1.4 mins
Alfentanil: protein binding
92 % Binds to α1- acid glycoprotein
Alfentanil: Metabolism
-CYP 3A4
-Noralfentanil
Alfentanil: Special Considerations
USE IN PARKINSON’S = ACUTE DYSTONIA
Fentanyl: Dose (Induction)
1.5 - 3 𝝻g/ kg IV
**give 5 mins prior
Fentanyl: Other doses
-Analgesia: 1-2 𝝻g/kg IV
-Adjunct with inhaled gases: 2-20 µg/kg IV
-Surgical Anesthesia:(solo): 50-150 µg/kg
-Transdermal: 75-100 µg (18 hr steady state delivery
-Transmucosal (oral): 5-20 µg/kg
-Peds 2-8 yo: 15-20 µg/kg PO 45 min prior
***1 mg PO Fentanyl=5 mg PO morphine
Fentanyl: Onset
30 - 60 seconds
Fentanyl: Duration
1 - 1.5 hours
Fentanyl: Metabolism
-CYP3A
-Metabolite: Norfentanyl
Fentanyl: CNS
‣**Seizure like activity **on SSEP and EEG with **doses > 30 µg/kg IV **
‣ ↑ ICP (6-9 mmHg)
Remifentanil: Structure
Ester structure
Remifentanil: Doses (Induction)
0.5 - 1 µg/kg over 1 min
DOSE IN IBW
Remifentanil: Other Doses
Maitenance:
- 0.25-1 µg/kg n IV
OR
- 0.125-0.375 µg/kg/min IV
* before stopping give longer acting opioid*
Remifentanil: Onset
30 - 60 secs.
Remifentanil: Metabolism
Hydrolysis by plasma and tissue esterases allows for:
- Brief action,
- Rapid onset and offset,
-Lack of accumulation
-Rapid recovery when discontinued.
SIMILAR TO PROPOFOL AND KETAMINE
Remifentanil: Clearance
-Kidneys (unaffected by renal or liver dx)
-3L/min
8x faster than alfentanil
Sufentanil: Dose (Induction)
18.9 µg/kg IV
Sufentanil: Other doses
Analgesia: 0.1-0.4 µg/kg IV
Sufentanil: Onset
30 - 60 secs.
Sufentanil: Clearance
-Renal and fecal
-Caution with chronic renal failure
Sufentanil: Other Side Effects
CHEST WALL AND ABDOMINAL MUSCLE REIGIDITY.
