Opioid and Opioid Tolerance Flashcards
Agonist
Strong agonist: morphine, hydromorphone, oxymorphone,
methadone, meperidine, fentanyl, levorphanol
Partial agonist
codeine, oxycodone, hydrocodone,
propoxyphrene
Antagonist
Nalorphine, naloxone, naltrexone
Mixed agonist-antagonist
Nalbuphine,burenorphine, butophenol, pentazocine
Short-acting
All medication released at once
Peaks and valleys effect
Acute or break through pain
Long-acting examples
MS Contin, Oxycontin, Kadian
long acting do not
crush you will get a bolus and overdose
long acting remember
Small amounts released over time, providing more stable
blood level
Good for chronic pain management
new recommendations are calling for
short acting
Clinical Indications for opioids
Acute and chronic pain, Acute pulmonary edema
Route and Onset
Parenteral 5-15 min Neuraxial 5 min Transdermal 16-24h Transmucosal (Oral and nasal) rapid-15min IM 60 min (erratic) PO 40-60min Intrathecal/epidural 5-15min
Opioid MOA
Bind to receptors in CNS (Mu, Kappa, Delta)
Supraspinal (medulla and midbrain) - MOA
Activation of post-synaptic neurons
Inhibition of neurons involved in pain transmission by
increased influx of K+
Spinal MOA/Activity
Activation of presynaptic receptors
Increased Ca++ influx and decreased release of
nociceptive neurotransmitters
Absorption/Distribution/ Metabolism/Elmination
Absorption First pass effect Distribution Lungs liver kidney spleen slow penetration of blood Lungs, liver, kidney, spleen, slow penetration of bloodbrain barrier; storage in fat, skeletal muscle Metabolism Elimination: renal
MU 1
Mu1: Supraspinal analgesia, euphoria, miosis, bradycardia,
urinary retention
MU 2
Mu2: Spinal analgesia, respiratory depression, decreased GI
KAPPA
Kappa: Supraspinal/spinal analgesia, sedation, miosis,
diuresis, hallucinations, respiratory depression
DELTA
Delta: supraspinal analgesia, respiratory depression, urinary
retention
Opioid Other effects
Other Effects: constipation, biliary colic, orthostatic
hypotension
opioid tolerance is dependent on
Dependent on dose, dosing frequency, duration and
consistency of use
opioid tolerance charcitresitics
Shorter duration of pain relief
Decrease in peak analgesic effect
Increasing amount needed to achieve relief
opioid tolerance managment
Lengthen time between doses
Increase dose to avoid shorter dosing interval
no more than ___ MME for acute pain
700
Opioid Dependence
3 or more of the following:
Drug tolerance Withdrawal symptoms Use of the drug in larger amounts or for longer i d th i d f Significant time spent obtaining the substance or recovering from its effects Foregoing of important activities or willingness to periods than required for medical necessity Repeated unsuccessful attempts to decrease or discontinue use Drug use to avoid withdrawal activities, or willingness to accept severe physical, social, or professional negative consequences, due to drug use
Physical Dependence
Repeated opioid use leads to physical adaptation
of body to drug and physical need for opioids
Withdrawal symptoms experienced when off
opioids for
36-72 h
duration of withdrawal
2 to 5 weeks
physical dependence resutls in
continued use of drug despite negative consequences
Psychological Dependence
Continued drug use for reasons other than tolerance
and withdrawal, such as the experience from a
drug’s pleasurable effects or to block out or to
escape from reality
Addiction
Addiction is a primary, chronic, neurobiologic disease,
with genetic, psychosocial, and environmental factors
influencing its development and manifestations. It is
characterized by behaviors that include one or more
of the following: impaired control over drug use,
compulsive use, continued use despite harm, and
craving.
American Pain Society
Opioid Addiction
Most severe form of dependence
Patient has uncontrollable cravings for the drug
Is willing to risk any adverse consequences to obtain
it
Requires ever-higher doses in order to ward off
withdrawal and/or to obtain the pleasurable
narcotic high associated with the drug
Drug interactions
CNS depressants
Sedative- hypnotics, alcohol, anesthetics, barbiturates
GI/GU effects (constipation, urinary retention)
Anticholinerg , ,p ics, TCAs, phenothiazines
MAOIs (coma, HTN)
Cimetidine enhances opioid effects
Diuretics (orthostatic hypotension)
Nicotine decreases effects of opioids
Contraindications and Precautions
Use in patient with head injuries Pregnancy Impaired pulmonary Hypersensitivity Abdominal pain Labor and Delivery Impaired pulmonary ETOH function Impaired hepatic or renal function ETOH Prostate disease Urinary strictures
