Pharmacology

Question 1

Tapentadol (Nucynta)

Answer 1

Mu-opioid receptor agonist and SNRI properties.
50-100mg q 4-6 hours
Can give additional dose as soon as 1 hour after 1st dose if needed.
Less potent than morphine.

Question 2

Methadone is better for this kind of pain than other opioids

Answer 2

Neuropathic or mixed nociceptive-neuropathic.

Question 3

When titrating from one opioid to another due to unacceptable side effects, you should decrease the new dose:

Answer 3

25-50%

Question 4

The increase opioid sensitivity seen when switching to a new opioid is called:

Answer 4

Incomplete-cross tolerance.

Question 5

If you are switching a patient because their pain was not controlled on the previous opioid:

Answer 5

You can consider using the calculated dose of the new opioid.

Question 6

In case of severe pain at the time of the switch:

Answer 6

You may have to increase the dose of the new drug from what it was converted to.

Question 7

When a patient has the previous drug left in their body or a long acting drug:

Answer 7

Consider the remaining drug in the body and time the dosing of the new drug appropriately.

Question 8

S/s of opioid toxicity

Answer 8

Constipation, nausea, sedation, itchiness, dizziness, confusion, hallucinations, vomiting, dry mouth, urinary retention, sweating, rash or hives.

Question 9

Rectal morphine has a bioequivalence to oral morphine of:

Answer 9

1:1

Question 10

Rectal hydromorphone has a ___ duration of action so its dosing is:

Answer 10

Longer; Q6H

Question 11

Rectal drugs should not be administered to:

Answer 11

Patient who are dehydrated (insufficient fluid in the rectal vault), through ostomies, patients with diarrhea, colostomy, hemorrhoids, anal fissures or neutropenia.

Question 12

Rectal drugs have a ___ amount of variability in absorption

Answer 12

high

Question 13

Medications administered via IV are ____ percent bioavailable.

Answer 13

100%

Question 14

Limit of SQ fluid:

Answer 14

2mL per injection or 1-2mL/hr with infusion.

Question 15

Morphine Equianalgesia Parenteral to Oral

Answer 15

10:30

Question 16

Oxycodone equianalgesia Parenteral to Oral

Answer 16

10:20

Question 17

Oxymorphine equanalgesia Parenteral to Oral

Answer 17

1:10

Question 18

What is the problem with Meperidine?

Answer 18

Short acting, repeat dosing causes metabolites that cause CNS excitation. Do not give with renal failure or elderly population.

Question 19

Normal Cr/CL

Answer 19

100 mL/min

Question 20

Better opioid drugs in renal failure

Answer 20

Hydromorphone, Oxymorphone, methadone, fentanyl.

Question 21

How to treat acute severe pain in the opioid naive patient.

Answer 21

Morphine 1mg IV q minute for 10 minutes, followed by a 5 minutes respite and repeated until pain is controlled.

Subcutaneous morphine 2mg q 5 min or fentanyl 40mcg or hydromorphine 0.4 mg.

Oral 5mg PO IR Morphine or 1 mg hydromorphone or 5mg oxycodone ever thirty min until pain recedes.

Question 22

What does controlled pain mean?

Answer 22

Initial 2-4 point drop in pain rating, not complete relief of pain.

Question 23

Another guideline for opioid naive patients with moderate to severe pain:

Answer 23

1-5mg morphine IV and reassess at 15 min, then if needed, double the dose and reassess after 15 min for 2-3 cycles.

Question 24

How to start ATC pain management

Answer 24

IR medication (Morphine) q 4 hours with same dose available for PRN 1-2 hours. Ask patient to keep pain diary. Increase opioid dose every 24 hours. Consider transitioning to oral sustained release.

Question 25

Methadone time of onset

Answer 25

10-15 min.

Question 26

How to deal with spontaneous pain

Answer 26

May be neuropathic. Give IR opioid as needed and consider co-analgesic.

Question 27

The more lipid soluble an opioid is:

Answer 27

The quicker the onset of action.

Question 28

Pharmacokinetic properities of morphine

Answer 28

Onset:30-40 min, Duration 4 hours

Question 29

Pharmacokinetic properties of oxycodone

Answer 29

Onset: 30 min, Duration 4 hours

Question 30

Pharmacokinetic properties of oxymorphone

Answer 30

30 min, 4-6 hours

Question 31

Pharmacokinetic properties of hydromorphone

Answer 31

30 min, 4 hours

Question 32

pharmacokinetic properties of methadone

Answer 32

10-15 min, 4-8 hours

Question 33

pharmacokinetic properties of transmucosal fentanyl

Answer 33

5-10 min, 1-2 hours.

Question 34

How do we dose rescue pain medication with long active opioids?

Answer 34

10-15% of TDD for rescue dose.

Question 35

How do we dose rescue meds for IR drugs ATC?

Answer 35

25-50% of scheduled q4hour dose q 1-2 hours.

Question 36

Rule of rescue dosing:

Answer 36

If less than 50 percent of the pain is relieved: double the dose.
If 50-100 percent of the pain is relieved: increase dose by half.
If close to 100% of the pain is relieved: no dose change.

Question 37

Oral transmucosal fentanyl

Answer 37

Cannot be dosed by rules.