Analgesic Agents Flashcards
What are A-fibers?
Nerve fibers that carry perceptions of vibration, stretch, and pressure.
There are four types: alpha,beta, gamma, and delta
What are A-delta fibers?
Fibers that carry the sensation of pain to the spinal cord (usually acute sharp pain)
What are C fibers?
Are un-myelinated nerve fibers (the fact that they’re un-myelinated means the conduction is slower)
- They also carry pain sensation to the spinal cord, but they carry more of a slow, dull aching pain
What are ergot derivatives?
Drugs that help with migraines by causing vasoconstriction in the brain and peripheral areas
Have lots of adverse effects
What is gate control theory?
The concept that pain is not just about how much damage tissues receive, but about how pain is transmitted through the nerve fibers, and that there are ways that we can close the pain gate with alternative means.
What is a migraine headache?
Severe unilateral pain in the head that leads to other effects such as nausea, vomiting, and photophobia and is usually caused by arterial dilation.
Whats nociception?
The transmission of unpleasant stimuli to the brain
What’s Triptan?
Selective serotonin blocker that cause vasoconstriction in the brain and is used as treatment for migraines.
What are opioid receptors responsible for?
- CNS
- nerves in the periphery
- cells in the GI tract
- chemo trigger zone (controls nausea, vomiting, breathing, and cough)
Use of opioids across the lifespan: CHILDREN
- Opioids in children have not proven to be effective or safe for use.
- Dosage should be carefully calculated
- Monitor closely for ADE
Methadone should NOT be used in children
What is the antidote for an opioid overdose?
Naloxone aka narcan
When should patients take opioids for pain?
Take them before the pain is unbearable
If they wait until the pain is unbearable that can increase breakthrough pain and it will take longer to get the pain back under control.
Opioid use across the lifespan for adults:
- encouraged to request pain meds before pain is out of control.
- caution in pregnancy and lactation (opioids can be used during the labor process, but only to a certain point in labor)
- narcotics used during labor, monitor and closely for adverse effects
- babies who were exposed to narcotic use while still in the womb can start to show withdrawal symptoms around 24 to 74 hours after delivery.
Use of opioids across the lifespan: OLDER ADULTS
- before just giving them opioids when their ordered, ask them first if they want pain meds.
- more likely to experience adverse effects
- implement safety measures (fall risk)
- if older adults have renal or hepatic problems are more likely to accumulate the drug and develop toxic levels.
Opioid agonists:
- Drugs that react with opioid receptors
- Cause analgesia, sedation or euphoria
- Potential for physical dependence
- They are controlled substances
- Rising problem of addiction
Drug class: Opioid agonists
What are the drug names or suffixes?
Morphine
Hydromorphone
Codeine
Oxycodone
Fentanyl
Hydrocodone
Drug class: Opioid agonists
What is the action?
- act at specific opioid receptor sites in the central nervous system, and produce analgesic sedation and a sense of well-being.
Drug class: Opioid agonists
What is the indication?
-relief of severe, acute or chronic pain and analgesia during anesthesia.
Can be used: during procedures or surgery for moderate sedation, general anesthesia, pain control after surgery, or chronic pain.
Drug class: Opioid agonists
What are the contraindications?
- Known allergy
- Diarrhea caused by poisons
^ A strict contraindication of opioid antagonist is when patients have diarrhea caused by poisons.
This is because the opioid agonist will cause decreased GI motility, which will increase poison absorption (the poison sits in the G.I. tract for longer, allowing more of it to enter the bloodstream)
Drug class: Opioid agonists
What are the cautions?
-respiratory dysfunction, asthma, emphysema (patients that already have respiratory problems can become worse because of the respiratory depression that comes with opioids)
-pregnancy, lactation, labor
-G.I. or GU surgery (Will complicate recovery by retaining urine and excrement)
-acute abdomen or ulcerative colitis (opioids can mask important symptoms of acute abdomen, which is short term for sudden onset of severe abdominal pain)
-head injuries, alcoholism, delirium tremens, or stroke (CVA).
(Opioids can exacerbate confusion and agitation, which makes management of delirium tremens more challenging, and they can impair consciousness and and cognitive function, which complicates the assessment of neurological status and head injury patients)
Drug class: Opioid agonists
What are the adverse effects?
- Respiratory center depression can lead to apnea cardiac arrest or shock.
- G.I. motility and CTZ stimulation can lead to nausea, vomiting, and constipation.
- CNS: dizziness, fear, anxiety, and hallucinations.
- Orthostatic hypotension.
- to avoid sedative effects try using the extended release forms of the medication instead*
Drug class: Opioid agonists
What are the drug-drug interactions?
- barbiturate general anesthetics ( combined with opioids, there is an increased risk of respiratory depression, hypotension, sedation, and coma)
- SSRIs ( combined with opioids, there is an increased risk of serotonin syndrome)
- caution should be taken when using opioid agonist with colic agents and antihypertensive agents as this could cause an increase in GI effects and hypotension.
Drug class: Opioid agonists- antagonists
What are the drugs or suffixes in this class?
-Buprenorphine
-Butorphanol
-Nalbuphine
Drug class: Opioid agonists- antagonists
What is the action?
Act as partial agonist at the mu-opioid, receptors and antagonist at the Kappa-opioid receptor in the CNS to produce analgesia, sedation, euphoria and hallucinations.
they can treat pain like opioid agonist, but unlike opioid agonist, they can be used as treatment for people with an opioid addiction
