Medication Assisted Therapy

Question 1

Important features of methadone

Answer 1

1. Full mu agonist
2. Weak affinity for mu receptor
3. Long half life (15-60hrs)

Question 2

Major features of buprenorphine

Answer 2

1. Partial agonist at mu recptor
2. High affinity for mu receptor (blocks and displaces other opioids)
3. Slow dissociation from mu receptor
4. Long half life (24-36 hrs)

Question 3

Buprenorphine administration

Answer 3

High first pass metabolism; need to use other routes such as SL to allow for suffient bioavailability.

Question 4

Buprenorphine mechanism of action

Answer 4

Has a high affinity and slow dissociation from mu receptor

• Prevents withdrawl
• Decreases cravings
• Decrease effect of other opioids
• Does not completely eliminate other opioid effects

Question 5

Buprenorphine/naloxone combination

Answer 5

• Created to decrease IV misuse (more likely to cause withdrawl if injected)
• Less euphoria
• Less likely to be diverted

Question 6

Naltrexone important features

Answer 6

1. Long acting
2. Full antagonist of mu receptor
3. High affinity for mu receptor (will block and displace other opioids; can cause withdrawl)

Question 7

Naltrexone administration

Answer 7

Fully blocks all opioid effects, preferred choice for pts who wish to avoid all opioids

• Poor adherence with oral formulation
• Monthly injection prevents issues with adherence

Question 8

Function at mu receptor

1. Full agonist
2. Partial agonist
3. Antagonist

Answer 8

Question 9

Specific concerns for:

Methadone

Buprenorphine

Naltrexone

Answer 9

Question 10

Buprenorphine adverse effects

Answer 10

Headache, constipation, xerostomia (dry mouth)

Question 11

Initiating Naltrexone

Answer 11

Patients should be opioid free for 7-10 days to avoid precipitated withdrawl. It can be difficult for patients to maintain abstience for this long a period d/t withdrawl.

Offer treatment for withdrawl while waiting for opioid to clear from system!