Analgesics Part 1 Flashcards
Steps of Nociception
Transduction, Transmission, Perception of pain, Modulation
Definition of Pain
An unpleasant sensory and emotional experience associated with actual or potential tissue damage
Pain Threshold
Level of stimulus needed to produce a perception of pain. (Measure of the physiological response of the nervous system)
Pain Tolerance
Amount of pain a person can endure without it interfering with normal function.
Pain tolerance is always:
Subjective and Patient-specific
What are the 2 classifications of pain?
Acute and Chronic
What is acute pain
Sudden onset that is limited (It can end)
What is Chronic pain?
Persistent or recurring; 3 - 6 months.
What are the other types of pain?
Referred, Neuropathic, Phantom, Cancer, Central and Vascular
What is Transduction
Transformation of stimuli into electrochemical energy
What is the point of spinal cord entry?
Dorsal horn
What pain-mediating chemicals are released during transduction?
Bradykinin, Histamine, Prostaglandins, Potassium, Serotonin, Substance P
What happens if no impulses are transmitted to the brain?
There is no pain perception
What are the two types of nociceptor fibers?
Small C fibres
Large A-delta fibres
The larger number of mu receptors :
The less the pain is perceived
What is Modulation
Neural Activity that controls pain transmission to neurons
What are the ways to treat pain in special situations?
Patient-controlled analgesia(PCA)
Patient comfort vs fear of drug addiction
Opioid tolerance
Use of placebos
Recognizing opioid tolerant patients, Breakthrough pain
Synergistic effects
What are Adjuvant drugs
Drugs from chemical categories other than opioids
What is the purpose of adjuvant drugs
Assisting primary drugs in relieving pain
What are some examples of adjuvant drugs?
NSAIDs
Antidepressants (Amitriptyline)
Anticonvulsants (Gabapentin)
Corticosteroids
Describe the WHO Analgesic Ladder
1: Nonopioids with or without adjuvant meds.
2: Opioids with or without nonopioids and with or without adjuvants
3: Opioids for more severe pain with or without nonopioids or adjuvant medications
What are opioids
Synthetic Drugs that bind to opiate receptors to relieve pain
What is the Opioid ceiling effect?
When it reaches its maximum analgesic effect
What are the 3 classifications of opioids
Agonists
Agonists-antagonists
Antagonists
What is another name for agonists-antagonists?
Partial or weak agonists
What is another name for antagonists?
Competitive antagonists
What are the 3 types of opioid receptors
Mu, Kappa, Delta
What are equianalgesia
The ability to provide equivalent pain relief by calculating dosages of different drugs or routes of admin that provide comparable analgesia
What are the indications for opioids
Moderate to severe pain
Often given with adjuvants to assist primary drugs with pain relief
Cough Centre suppression (codeine)
Treatment of diarrhea
What are the contraindications for opioids?
Allergies, severe asthma
In what cases do you exercise extreme caution when giving opioids
Respiratory insufficiency
Elevated intracranial pressure
Morbid obesity or sleep apnea
Paralytic ileus
Pregnancy
What are the adverse effects of opioids?
CNS and respiratory depression
Constipation
Urinary retention
Hypotension
Itching
rash
Constricted pupils indicating possible OD.
