Chapter 10: Analgesic Drugs Flashcards
Analgesics
- Medications that relieve pain without causing loss of consciousness
- “Painkillers”
- Opioid analgesics
- Adjuvant analgesic drugs
Pain
An unpleasant sensory and emotional experience associated with actual or potential tissue damage
* A personal and individual experience
* Whatever the patient says it is
* Exists when the patient says it exists
* Pain involves:
* Physical factors
* Psychologic factors
* Cultural factors
Pain Management Approach
No single approach to effective pain management
* Tailored to each patient’s needs
* Consider:
* Cause of pain
* Existence of concurrent medical conditions
* Characteristics of pain
* Psychological and cultural characteristics
* Requires ongoing reassessment of pain and the effectiveness of treatment
Pain Threshold
Level of stimulus needed to produce the perception of pain
* A measure of the physiologic response of the nervous system
Pain Tolerance
The amount of pain a person can endure without it interfering with normal function
* Varies from person to person
* Subjective response to pain, not a physiologic function
* Varies by attitude, environment, culture, ethnicity
Acute pain
- Sudden onset
- Usually subsides once treated
Chronic pain
- Persistent or recurring
- Lasts 3 to 6 months
- Often difficult to treat
- Tolerance
- Physical dependence
Pain Transmission
- The nerve impulses enter the spinal cord and travel up to the brain.
- The point of spinal cord entry or the “gate” is the dorsal horn.
- This gate regulates the flow of sensory impulses to the brain.
- Closing the gate stops the impulses.
- If no impulses are transmitted to higher centers in the brain, there is no pain perception
- Body has endogenous neurotransmitters.
- Enkephalins
- Endorphins
- Produced by body to fight pain
- Bind to opioid receptors
- Inhibit transmission of pain by closing gate
- Rubbing a painful area with massage or liniment stimulates large sensory fibers.
- Result
- Closes gate
- Reduces pain sensation
Treatment of Pain in Special Situations
- PCA and “PCA by proxy”
- Patient comfort vs. fear of drug addiction
- Opioid tolerance
- Use of placebos
- Recognizing patients who are opioid tolerant
- Breakthrough pain
- Synergistic effect
Adjuvant Drugs
- Assist primary drugs in relieving pain
- NSAIDs
- Antidepressants
- Anticonvulsants
- Corticosteroids
- Example: adjuvant drugs for neuropathic pain
- Amitriptyline (antidepressant)
- Gabapentin or pregabalin (anticonvulsants)
Opioid Drugs
- Synthetic drugs that bind to the opiate receptors to relieve pain
- Mild agonists: codeine, hydrocodone
- Strong agonists: morphine, hydromorphone, oxycodone, meperidine,
fentanyl, and methadone - Meperidine: not recommended for long- term use because of the accumulation of a neurotoxic metabolite, normeperidine, which can cause seizures
MOA: binds to opioid receptors in the body
Equianalgesia
- Ability to provide equivalent pain relief by calculating dosages of different drugs or routes of administration that provide comparable analgesia
- Hydromorphone (Dilaudid): seven times more potent than morphine
- Example: if morphine 10 mg was given to a patient followed 1 hour later by hydromorphone 1 mg, then the patient would have received an equivalent of 17 mg of morphine.
A patient diagnosed with cholecystitis reports pain in the back and scapular areas. The nurse infers that the patient has which type of pain?
Referred pain
what is the PRIMARY indication for the administration of morphine?
to relieve acute and chronic pain
Medication used to treat patient experiencing severe adverse effects of an opioid analgesic.
Naloxone
which characteristic aligns with chronic pain?
Persistent
Which opioid is used to relieve coughing?
Codeine sulfate
Transdermal fentanyl is indicated for which type of pain?
severe pain resulting from cancer metastasis
pain from ulcers of the mouth is an example of _________ pain.
superficial pain
which condition is a contraindication for the administration of acetaminophen?
severe liver disease
A patient admitted to the ER with diagnosis of “acetaminophen overdose”. Which lab value is essential for the nurse to assess?
AST & ALT levels
Acetylcysteine
helps to prevent acetaminophen toxicity
fentanyl patch needs to be changed once every ____
72 hours
adverse effect of Levorphanol
constipation
gallstones produce which type of pain?
Visceral pain
Non Opioid (nsaids)
Examples: ibuprofen, aspirin, naproxen, ketorolac
Indication: pain, fever, anti platelet
MOA: they block the COX enzyme, which prevents the prostaglandin from producing inflammation that causes pain.
Adjuvant drugs
Example: Gabapentin
Indication: drugs added to an existing pain regimen to improvement pain control. Used for chronic pain. Also used for Neuropathic pain (nerve related pain).
ASA/ Aspirin is contraindicated in _____.
Children w/ fever and flu like symptoms . They can develop Reyes Syndrome.
Gabapentin (adjuvant)
A neurotransmitter in the Nervous System. Causes inhibitory effects for neuropathic pain. It limits the release of excitatory neurotransmitters (helps with pain and seizures by calming the neurons down).
Hydromorphone
(Dilaudid)
Given for pain reliever.
It also decreases BP, Respiration and heart rate
Considerations before giving Opioids
A (respiratory) : respiratory depression
B : birth defects / neonatal abstinence syndrome
C : bradycardia & hypotension
D (disability) : drowsiness, memory impairment, sedation. Euphoria and convulsions
E (eyes) : miosis which is pupil constriction
Cns depressants causes eye constriction
F (GI) : slows GI causes constipation & n/v
G (GU) : urinary retention due to depression of urinary sphincter
H : hypersensitive reaction (mild to severe)
P: (itching) pruritis from histamine release
Before giving meds: know Basic Needs!
A : airway
B: breathing
C : circulation
D: disability (neuro status) LOC
Nursing process:
- Assess
- Intervene
- Reassess
Malignant Hyperthermia
A genetic disorder of severe reaction from medications during general anesthesia causing life threatening complications.
Caused by using Anesthetic gases and succinylcholine (a muscle relaxant).
S/sx: muscle rigidity, high fever, tachycardia, hyperkalemia.
Treatment: Dantrolene (stops release of calcium going to muscles).
Antidote for local anesthesia
Phentolamine
Which drugs are Opioid agonist-antagonist ?
Nalbuphine
Butorphanol
Buprenorphine
(Opioid) Lortab adverse effects:
Urinary retention
Itching
Constipation
Drowsiness
Antidote for Acetaminophen
Acetylcysteine
Max dose of Acetaminophen in 24hr
3,000mg in 24 hr period
Antidote for Malignant Hyperthermia
Dantrolene
