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Flashcards in Morphine Deck (31):
1

What is the class of Morphine?

naturally occurring Opioid agonist
Analgesic

2

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

3

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

4

What is the major metabolite of Morphine? is it active?

Morphine 3-glucuronide (M3G)
Inactive

5

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!

6

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

7

How is Morphine eliminated?

principally in the urine as M3G

8

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

9

What is the Vd of Morphine?

large and about 3 - 4 L/kg in normal adults

10

Is morphine protein bound?

30 -35% protein bound

11

What are the CV effects of Morphine?

Decreases SNS tone in peripheral veins causing pooling, and decreasing venous return, decreasing BP- HISTAMINE RELEASE

12

What is a side effect of Morphine that most other opioids do NOT produce?

Histamine Relase

13

What are the CNS effects of Morphine?

Drowsiness
Dizziness
Confusion
Headache
Cognitive and fine motor impairment, euphoria, dysphoria and sleep disturbances
Miosis

14

What are the respiratory effects of Morphine?

Respiratory and cough reflex depression

15

What are the dermatological effects of Morphine?

Pruritis
Flushing
Erythema at injection site

16

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

17

What is the GU effects of Morphine?

urinary retention

18

What are the skeletal muscle effects of Morphine?

-Weakness
-Increase muscle tone causing muscle rigidity

19

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

20

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

21

As a balanced anesthetic (with controlled ventilation) what is the dosage of Morphine?

up to 2 mg/kg can be used

22

What is the continuous IV infusion dose of Morphine?

0.8 - 1 mg/hr (may increase to 80 mg/hr with high opioid tolerance)

23

What is the Epidural dose of Morphine?

3 - 5 mg

24

In pharmacodynamics, Morphine has poor _______ _______, highly ________ _______ and highly _________

poor lipid solubility, highly protein bound and highly ionized

25

What does morphine produce?

-Analgesia
-Euphoria
-Sedation
-Nausea
-Pruritis
-Dry mouth

26

Does Morphine produce ventilatory depression?

yes (but it might not happen until 20 minutes after injection)

27

When is the IM peak effect of Morphine?

45 minutes

28

When is the IV peak effect of Morphine?

15 - 30 minutes

29

Why does morphine cause bradycardia?

because of DIRECT stimulation of VAGUS nerve

30

What direct effects does Morphine have that affect the heart?

-direct stimulation of vagus nerve
-inhibition of SA node

31

Where is Morphine metabolized?

the liver