Morphine Flashcards
Please note that the drug card information is for Educational Use ONLY, and the source is from Carrie Bowman's glossary of drug cards permitted by use of Georgetown NAP students. No permission is given to use these cards for anything other than as a study resource for our program.
What is the class of Morphine?
naturally occurring Opioid agonist
Analgesic
What are the uses of Morphine?
- analgesia and used to supplement other agents during induction or maintenance of general anesthesia
- relief of moderate to severe acute and chronic pain
How is Morphine metabolized?
- Hepatic conjugation with glucuronic acid which converts morphine to its metabolites
- renal metabolism contributes significantly to the total metabolism of morphine and it explains the absence of decrease in systemic morphine clearance in patients with hepatic cirrhosis
What is the major metabolite of Morphine? is it active?
Morphine 3-glucuronide (M3G)
Inactive
What is the active metabolite of Morphone? What is special about it?
Morphine 6-glucuronide (M6G)
MORE potent producing analgesia and depression of ventilation, and can be longer lasting!
How is Morphine metabolized?
- Hepatic conjugation with glucuronic acid which converts morphine to its metabolites
- the kidneys also play a key role in extrahepatic metabolism
- renal failure will have effects due to M6G
How is Morphine eliminated?
principally in the urine as M3G
How is Morphine redistributed?
- After IV administration it is rapidly absorbed, with a mean redistribution half time btwn 1.5 - 4.4 minutes in awake and anesthetized patients
- only a small amt of morphine is distributed to the CNS ***this is due to poor lipid solubility, high degree of ionization at physiologic pH, protein binding and rapid conjugation with glucuronic acid
What is the Vd of Morphine?
large and about 3 - 4 L/kg in normal adults
Is morphine protein bound?
30 -35% protein bound
What are the CV effects of Morphine?
Decreases SNS tone in peripheral veins causing pooling, and decreasing venous return, decreasing BP- HISTAMINE RELEASE
What is a side effect of Morphine that most other opioids do NOT produce?
Histamine Relase
What are the CNS effects of Morphine?
Drowsiness Dizziness Confusion Headache Cognitive and fine motor impairment, euphoria, dysphoria and sleep disturbances Miosis
What are the respiratory effects of Morphine?
Respiratory and cough reflex depression
What are the dermatological effects of Morphine?
Pruritis
Flushing
Erythema at injection site
What are the GI effects of Morphine?
- N/V caused by DIRECT stimulation of CTZ of 4th ventricle
- Decreases peristaltic contractions which delays passage of GI content resulting in constipation
What is the GU effects of Morphine?
urinary retention
What are the skeletal muscle effects of Morphine?
- Weakness
- Increase muscle tone causing muscle rigidity
What are the contraindications to the use of Morphine?
- Increased ICP
- Severe respiratory depression
- Acute or Severe asthma
- known or suspected paralytic ileus and prolonged use or high doses at term during pregnancy
What is the IV analgesic dose of Morphine?
0.01 - 0.2 mg/kg; usually between 2.5 - 15mg IV in divided doses (titrate in small increments 1 - 4 mg q5 minutes) q 3 - 4hr
As a balanced anesthetic (with controlled ventilation) what is the dosage of Morphine?
up to 2 mg/kg can be used
What is the continuous IV infusion dose of Morphine?
0.8 - 1 mg/hr (may increase to 80 mg/hr with high opioid tolerance)
What is the Epidural dose of Morphine?
3 - 5 mg
In pharmacodynamics, Morphine has poor _______ _______, highly ________ _______ and highly _________
poor lipid solubility, highly protein bound and highly ionized
What does morphine produce?
- Analgesia
- Euphoria
- Sedation
- Nausea
- Pruritis
- Dry mouth
Does Morphine produce ventilatory depression?
yes (but it might not happen until 20 minutes after injection)
When is the IM peak effect of Morphine?
45 minutes
When is the IV peak effect of Morphine?
15 - 30 minutes
Why does morphine cause bradycardia?
because of DIRECT stimulation of VAGUS nerve
What direct effects does Morphine have that affect the heart?
- direct stimulation of vagus nerve
- inhibition of SA node
Where is Morphine metabolized?
the liver