Lecture 13 - Addiction & Drugs of Abuse Flashcards
What are the 5 characteristics of addiction?
- ABCDE
1) Inability to consistently abstain
2) Impairment in behavioural control
3) Craving
4) Diminished recognition of significant problem’s w/ one’s behaviours and interpersonal relationships
5) Dysfunctional emotional response
What is the diagnostic criteria for opioid use disorder?
Problematic pattern of opioid use leading to clinically significant impairment or distress, as manifested by at least 2 of the 11 criteria, occurring w/in a 12 month period
What is the criteria for mild, moderate, or severe opioid use disorder?
- Mild = presence of 2-3 symptoms
- Moderate = presence of 4-5 symptoms
- Severe = present of 6 or more symptoms
What are the 11 symptoms of opioid use disorder?
1) Taken in larger amounts or over a longer period than was intended
2) Persistent desire or unsuccessful efforts to cut down or control opioid use
3) Lots of time spent in activities necessary to obtain or use the opioid and recover from the effects
4) Craving
5) Failure to fulfill major obligations
6) Continued use despite problems caused or exacerbated by the effects of opioids
7) Important activities given up or reduced b/c of opioid use
8) Recurrent use in situations where it is physically hazardous
9) Continued use despite knowledge of a persistent or recurrent physical/psychological problem
10) Tolerance
11) Withdrawal
What is the definition of tolerance?
1) Need for markedly increased amounts of opioids to achieve intoxication or desired effect
2) Markedly diminished effect w/ continued use of the same amount of opioid
When is the criteria for tolerance not met?
When the px is taking opioids solely under appropriate medical supervision
When is the criteria for withdrawal not met?
When the px is taking opioids solely under appropriate medical supervision
What is the purpose of harm reduction?
Attempts to decrease harmful consequences of illicit drug use to the individual, family, community, & society
What are the goals of the harm reduction program?
Reduce illicit opioid use, needle sharing, criminal activity, and mortality associated w/ addiction
What are the pharmacological options for opioid use disorder?
- Methadone
- Buprenorphine/naloxone or buprenoprhine alone
Is methadone structurally related to opiates?
No
Is methadone an agonist or antagonist and for which receptor?
- Agonist for Mu(u) opioid receptor
- NMDA antagonist
What are the uses of methadone?
Analgesia and withdrawal management in opioid dependent individuals
What is the duration of action for methadone and what does this mean for dosing?
- Long duration
- Once daily dosing
Can methadone cause tolerance?
Not normally
How long does it take to reach peak plasma level for methadone, and why is it good to know this?
- 2-4 hours
- When a patient is overdosing, it will likely be when it is peaking and you will see symptoms during this time period
How long does it take to reach steady state w/ methadone?
5-7 days
What is the half-life of methadone?
22 hours, but can be 15-40 hours
With therapeutic doses of methadone, how long can withdrawal symptoms be suppressed for?
24-36 hours
What is methadone metabolized by?
CYP 3A4
Methadone is a weak inhibitor of which CYP enzyme?
2D6
How is methadone excreted?
As an unchanged drug and as metabolites in urine and feces
Amount of methadone excreted in urine _____ as pH decreases
Increases
What are common persistent adverse effects of methadone?
- Constipation
- Dental (dry mouth)
- Insomnia
- Neuroendocrine
- Sexual changes
- Sweating
