Pharmacology - Opioids (Exam 1) Flashcards
What are the 2 components of pain?
- specific sensation (physical)
- reaction to the sensation (psychological)
What are the two types of analgesics?
- Narcotic analgesics (opioid analgesics).
- Non-narcotic analgesics.
Opioid analgesics raise the threshold for _______ _______ and alter the ________ _________.
pain perception; affective response
What are the sites of opioid action?
- Thalamus
- Limbic system
- Brain stem
- Spinal cord
Where are opioid receptors and endogenous opioids located?
spinal cord
What are the 3 opioid receptors?
- Mu
- Kappa
- Delta
What are the pharmacological effects of morphine on specific body systems (7)?
- mood changes
- nausea and vomiting
- respiratory depression
- antitussive
- miosis
- urinary retention
- GI effects
What is associated with mood changes on morphine?
euphoria and mental clouding
Why does morphine cause nausea and vomiting?
opioids stimulate the chemoreceptor trigger zone (CTZ)
What are the 2 ways morphine causes respiratory depression?
- decreases response of brain stem respiratory neurons to CO2
- bronchoconstriction (release of histamine)
What are the GI effects of morphine?
constipation and antidiarrheal
All tolerance to opioids is ____________; there is NO _______ _________.
pharmacodynamic; metabolic tolerance
Opioid withdrawal is NOT life threatening
true
What are the general uses of opioid analgesics?
- analgesia
- antitussive
- antidiarrheal
Most opioids can relieve ___________ and are usually reserved for _______ to _______ pain.
all types of pain, moderate to severe
(T/F) not all opioids are equally effective and some are used only for moderate pain in combination with other analgesics.
true
we can compare opioid analgesics by
source and activity
what are some of the sources for comparison of opioid analgesics?
a. naturally occurring (morphine, codeine)
b. partial synthetic (heroin, naloxone)
c. synthetic (levorphanol, meperidine, methadone)
what are some of the activities for comparison of opioid analgesics?
a. agonist
b. antagonist
c. agonist/antagonist
What are the opioid agonists?
Morphine
Codeine
Oxycodone
Meperidine
Fentanyl
Methadone
What are the opioid antagonists?
Naloxone
Naltrexone
Naloxone is a pure, competitive _______ at all opioid receptors with NO opioid agonist activity
antagonist
What is the duration of action for naloxone?
1-4 hours (short)
Naltrexone is a pure, competitive ________ with a _____ hour duration of action.
antagonist; 24
How is naltrexone active?
orally active
What are the uses of pure antagonists?
- tx of opioid overdose
- diagnose addiction
- tx of compulsive use
What are the opioid mixed agonist-antagonists?
Pentazocine
Nalbuphine
Butorphanol
Buprenophrine
How is pentazocine used?
as an analgesic for mild to moderate pain
Pentazocine is a weak ______ antagonist. It blocks ______ ________ and induces opioid (mu) withdrawal in the physically dependent. Does NOT block _______ _______ ________.
mu; morphine analgesia; morphine respiratory depression
Pentazocine is an agonist at _____ and ______ receptors.
kappa; sigma
Pentazocine as an agonist at kappa and sigma receptors causes the following effects:
- _______ analgesia that is as effective as morphine analgesia
- _______ ________ of the limited type, not as severe as that of morphine.
- ________ and ________, especially with repeated high doses
- spinal
- respiratory depression
- dysphoria; hallucinations
How are Nalbuphine and Butorphanol used?
as an analgesic for moderate to severe pain
Nalbuphine and Butorphanol are _____ antagonists that can antagonize _______ ________ and induce abstinence syndrome in those who are physically dependent to morphine.
mu; morphine analgesia
Nalbuphine and Butorphanol are ______ agonists that:
- produce effective analgesia with limited ________ _______.
- ______ incidence of psychotomimetic effects.
- mild _________ ________.
- antagonized by ________.
kappa
- respiratory depression
- low
- abstinence syndrome
- naloxone
How is Buprenorphine used?
as an analgesic for moderate to severe pain
Buprenorphine is a partial ______ agonist. The effects it induces are ______ in onset and ______ lasting.
mu; slow; long
The effects of Buprenorphine as a partial agonist at mu receptors include what 5 things?
- analgesic
- respiratory depression (minor)
- euphoria
- miosis
- mild morphine type abstinence sundrome
Buprenorphine is a ________ antagonist. It is antagonized by _______.
kappa; naloxone
Why does heroin cross the BBB rapidly?
due to high lipid solubility
How is codeine active?
orally active
What is the potency and efficacy of codeine in comparison to morphine?
1/10th the analgesic potency
not as efficacious
What is codeine used for?
antitussant (cough)
analgesic (w/ aspirin or aceptaminophen)
What is the potency and efficacy of oxycodone in comparison to morphine?
same potency
same efficacy
(but oxycodone has higher oral activity)
What are the synthetic opioids?
Meperidine
Fentanyl
Methadone
How is meperidine active?
orally active
What is the potency and duration of action of meperidine in comparison to morphine?
1/10 the potency
shorter duration of action (used for shorter analgesia)
How is fentanyl active?
orally active, but used IV for anesthesia
What is the potency and duration of action of fentanyl in comparison to morphine?
80x the potency
shorter duration of action (serum half-life of 20 mins!)
Fentanyl is VERY _______ soluble, so it’s pharmacokinetics are similar to _______.
________ is the major means of termination of action.
lipid; thiopental; redistribution
What is fentanyl used for clinically?
- anesthetic induction
- sole anesthetic for cardiac surgery
- neuroleptic state (combined w/ droperidol in innovar)
Which 2 drugs are similar to fentanyl in action and use?
Alfentanil
Sufentanil
How is methadone active?
orally active
What is the potency and action of methadone in comparison to morphine?
same potency
same actions
Is the duration of action for methadone long or short?
LONG
What is the half-life for methadone?
15 hours (less severe side effects)
What are the uses of methadone?
- chronic pain
- methadone maintenance
What is the triad of symptoms for opioid overdose?
- coma
- depressed respiration
- miosis (pinpoint pupils)
How do you treat an opioid overdose?
- restore respiration
- administer naloxone (narcan)
- watch pt. (may have to administer naloxone again)
What is one opioid interaction?
neuroleptic analgesia
