Chapter 12 Opioids Used for Mild to Moderate Pain Flashcards
World Health Organization Analgesic Ladder- Step 1
Mild pain is usually treated with over-the-counter (OTC) analgesics such as aspirin, ibuprofen, or acetaminophen. These agents exert their effect by mitigating the “algogenic soup” that follows tissue injury.
World Health Organization Analgesic Ladder- Step 2
For mild to moderate pain, the WHO analgesic ladder
advocates the use of short-acting opioids (SAOs) either
alone or in conjunction with OTC analgesics. In addition,
adjunctive therapy such as acupuncture, transcutaneous
electrical nerve stimulation, and/or psychotherapy may be brought into play at this stage
World Health Organization Analgesic Ladder- Step 3
The third step, to relieve moderate to severe pain, entails the use of high-potency SAOs or long-acting opioids (LAOs), either alone or with adjunctive therapy
The duration of action of SAOs ranges from
2 to 4 hr, and they are available as single entity medication or in combination with a nonopioid, such as acetaminophen or a nonsteroidal anti-inflammatory drug (NSAID)
Advantages or Disadvantages of Combination therapy (nonopioid, such as acetaminophen or a nonsteroidal anti-inflammatory drug (NSAID) with opioid)
Combination therapy offers drug-sparing effects since a lower dose of each medication is used, avoiding side effects associated with higher doses. However, a potential problem is created by combining an opioid, which can produce tolerance and that has no dose ceiling, with acetaminophen or an NSAID, which may cause toxicity beyond a certain dosage
“Weak Opioids.”
When opioids are administered with aspirin, acetaminophen, or ibuprofen
Oxycodone
Oxycodone is a semisynthetic opioid processed from thebaine, an organic chemical found in opium.
Oxycodone compared to Morphine
oral administration has high bioavailability (60%); oxycodone is 1.5 to 2 times more as potent as morphine. High abuse potential
Oxycodone metabolism
Unlike morphine and hydromorphone, oxycodone
is metabolized by the cytochrome P450 enzyme
system in the liver, making it vulnerable to drug
interactions.
Federal Controlled Substance Schedule I
Have no currently accepted medical use and high potential for abuse, addiction, or physical dependence.
Ex: Heroin, lysergic acid, marijuana, mescaline, methaqualone
- Federal Controlled Substance Schedule II
Have accepted medical use and high potential for abuse, addiction, or physical dependence
Ex: Morphine, hydromorphone, methadone, oxycodone,
cocaine, amphetamine, methlphenidate
- Federal Controlled Substance Schedule III
Have accepted medical use and potential for abuse, addiction, or physical dependence less than drugs in Schedules I and II.
Ex: Opioids combined with non-narcotic drugs (e.g.,
hydrocodone/acetaminophen, codeine combination),
dronabinol, anabolic steroids, benzphetamine
Federal Controlled Substance Schedule IV
Have accepted medical use and potential for abuse, addiction, or physical dependence less than drugs in Schedules I–III.
Ex: Benzodiazepines, chloral hydrate, dextropropoxyphene, phenobarbital, fenfluramine
Federal Controlled Substance
Schedule V
Have accepted medical use and potential for abuse, addiction, or physical dependence less than drugs in Schedules I–IV.
Ex: Diphenoxylate in combination with atropine (antidiarrheals), antitussives with limited amounts of narcotics (e.g., codeine)
Hydrocodone
Hydrocodone is an opium derivative and is Schedule III
when in combination with acetaminophen or ibuprofen
and Schedule II when used as a single entity product
Hydrocodone vs. Morphine
Morphine Equivalent Conversion Factor
per Milligram of Opioid is 1.0
Hydrocodone metabolism
Hydrocodone is metabolized by the liver into several metabolites, and has a serum half-life of 3.8 hr
CODEINE
Codeine is an opioid metabolized to active analgesic compounds, including morphine.
How is Codeine administered?
This opioid is frequently administered in combination with acetaminophen, butalbital, and caffeine intended for the treatment of headache and commonly employed as an antitussive
Codeine vs. Morphine
Morphine Equivalent Conversion Factor per Milligram of Opioid is 0.15
Metabolism of Codeine
Unlike morphine and hydromorphone, oxycodone
Is metabolized by the cytochrome P450 enzyme
system in the liver, making it vulnerable to drug interactions
*Tramadol (Ultram) mechanisms of action
agonist activity at the mu opioid receptor as well as Inhibition of the reuptake of norepinephrine and serotonin. (SNRI)
How is Tramadol (Ultram) used in children?
Tramadol 1 to 2 mg/kg is an effective oral agent in
the postoperative period in children ready to be transitioned from patient-controlled analgesia
Adverse events with Tramadol (Ultram)
Nausea, dizziness, somnolence, and headache
association of seizure activity (This risk is increased by a history of alcohol abuse, stroke, head injury, or renal compromise.)
Avoid combining Tramadol with what medication? Why?
patients receiving serotonin selective reuptake inhibitors should avoid taking tramadol due to the risk of producing the serotonin syndrome. The excess serotonin activity produces a spectrum of specific symptoms including cognitive, autonomic, and somatic effects. mild (shivering and diarrhea) to severe (muscle rigidity, fever and seizures). Severe serotonin syndrome can be fatal if not treated.
Tapentadol
a centrally acting analgesic with dual mechanisms of action: μ-opioid receptor: agonist activity and norepinephrine reuptake inhibition
Tapentadol dosage
Currently, it is not recommended to exceed more than 700 mg/day of tapentadol on the first day of therapy and no more than 600 mg/day on subsequent days with most patients taking 50 to 100 mg every 4 to 6 hr as needed for pain
Federal Controlled Substance Schedules for Tapentadol
Tapentadol is a Schedule II controlled substance with abuse potential similar to other potent opioid analgesic
Tapentadol adverse effects
nausea, vomiting, constipation,
dizziness, and somnolence
Propoxyphene
Propoxyphene hydrochloride is an odorless, white crystalline powder with a bitter taste that is freely soluble in water.
What is Propoxyphene analgesic effect due to?
Although propoxyphene is no stronger than acetaminophen, it remains a relatively popular analgesic with increased interest spurred by the finding that the d-isomer, dextropropoxyphene, is a noncompetitive NMDA receptor antagonist
Propoxyphene adverse effects
Are dizziness, sedation, nausea, and vomiting. more
serious potential problems including seizures, cardiac dysrhythmias, and even heart block if taken in excessive amounts, either accidentally or because of suicidal intent
Risk factor for accidental overdose
Concomitant use of alcohol, sedatives, tranquilizers, muscle relaxants, or antidepressants
NSAIDs should be considered possible first-line agents for
Most acute injuries and minor surgical procedures
In postoperative pain management, the basis for using nonopioid analgesic adjuvants is to reduce
Opioid consumption and lessen opioid-related adverse effects
In what cases is Opioid analgesics might be advantageous over NSAIDs?
Low platelet count: NSAIDs cause platelet dysfunction,(relatively contraindication) patient with a low threshold for bronchospasm. pregnancy (increase the risk of miscarriage) NSAIDs as a group tend to exacerbate reflux esophagitis and peptic ulcer. also are patients with CHF, intrinsic renal disease, liver failure with ascites, and those receiving diuretics. Opioid analgesics used with caution because most are excreted by the kidneys and metabolized by the liver
When analgesia is poorly controlled with acetaminophen, salicylates, or an NSAID add…
A weak opioid (e.g., codeine, oxycodone, tramadol, or hydrocodone) can be added to bring about additional pain relief
LAOs are believed to be preferable for chronic pain because they
Provide less variation in blood levels and possibly promote a lower propensity for the development of abusive behaviors
