How does the International Association for Study of Pain define pain?
As an unpleasant sensory and emotional experience associated with actual or potential tissue damage.
p.1
Subjective Nature of Pain Experience
What factors influence the pain experience?
Behavioral, physiologic, sensory, emotional, and cultural factors.
p.1
Subjective Nature of Pain Experience
What is the pain threshold?
The point at which an individual first acknowledges or interprets a sensation as being painful.
p.1
Subjective Nature of Pain Experience
What does pain tolerance refer to?
An individual’s ability to endure pain.
p.2
Classification of Pain: Acute vs Chronic
What is acute pain?
Short-term pain that arises from sudden injury to body structures.
p.12
Narcotic Analgesics and Their Mechanism
What do narcotics bind to in the body?
Opioid receptors in the CNS and peripheral nervous system (PNS).
p.8
Nociceptive Pain Mechanisms
What is transduction in the context of nociception?
The process by which nociceptors are stimulated, though the exact mechanism is not fully understood.
p.3
Pathophysiological Classification of Pain
What is phantom limb pain?
Neuropathic pain felt in the area where an arm or leg has been amputated.
p.29
Acetaminophen: Uses and Risks
What occurs in the minor pathway of acetaminophen metabolism?
Acetaminophen is oxidized by cytochrome P450-containing enzymes into a highly reactive metabolite, N-acetyl-p-benzoquinoneimine.
How can analgesics be categorized?
Into three categories: Narcotic (opioid) analgesics, Non-narcotic analgesics, and Adjuvant analgesics.
p.23
Adverse effects of Aspirin
What symptoms are associated with Salicylism?
Tinnitus, headache, dizziness, and respiratory alkalosis.
p.10
Narcotic Analgesics and Their Mechanism
What happens when opiates stimulate opiate receptors?
They block the pain sensation.
p.14
Narcotic Analgesics and Their Mechanism
Where does morphine primarily act to suppress pain?
In the brain, activating the descending pain suppression pathway.
p.18
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)
What do Non-Steroidal Anti-Inflammatory Drugs (NSAIDs) inhibit?
Cyclooxygenase (COX) enzymes.
How does Celecoxib reduce pain sensation?
By reducing prostaglandins (PGs) as inflammatory mediators.
p.5
Nociceptive Pain Mechanisms
What is transduction in the context of nociceptive pain?
The release of chemical mediators following tissue injury.
p.23
Adverse effects of Aspirin
What are the hepatic effects of Aspirin?
Dose-dependent hepatic damage.
In what situation is Celecoxib used for severe pain?
When combined with opioids for surgical and cancer pain.
p.17
Narcotic Analgesics and Their Mechanism
What limits the use of narcotics for chronic pain?
Tolerance and physical dependence.
p.12
Narcotic Analgesics and Their Mechanism
What is the effect of narcotics on pain perception?
They decrease the perception of pain, decrease reaction to pain, and increase pain tolerance.
p.12
Narcotic Analgesics and Their Mechanism
What type of chemical are narcotics considered?
Psychoactive chemicals with analgesic effects.
p.19
Nociceptive Pain Mechanisms
What is the primary function of COX-2?
To mediate inflammation and pain at the site of inflammation.
p.15
Narcotic Analgesics and Their Mechanism
What is the primary function of agonist drugs?
They occupy receptors and activate them.
p.15
Narcotic Analgesics and Their Mechanism
How do antagonists affect receptor activation by agonists?
Antagonists block receptor activation by agonists.
What type of pain is Celecoxib used for?
Mild to moderate pain associated with inflammation.
p.29
Acetaminophen: Uses and Risks
What are the two pathways for acetaminophen metabolism?
Major pathway and minor pathway.
What conditions can Celecoxib be used to treat?
Rheumatoid arthritis and osteoarthritis.
p.18
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)
What type of drugs are corticosteroids in relation to inflammation?
They are anti-inflammatory drugs that inhibit different inflammatory mediators.
p.23
Adverse effects of Aspirin
What is Reye’s Syndrome and its associated risks?
A condition in children that can lead to 20% death, characterized by hypoglycemia, rash, vomiting, and liver damage.
What is the role of corticosteroids in pain management?
They decrease inflammation.
p.10
Narcotic Analgesics and Their Mechanism
How many types of opiate receptors are there?
Four types: mu (μ), delta (δ), kappa (κ), and epsilon (ε) receptors.
p.30
Acetaminophen: Uses and Risks
What happens during an acetaminophen overdose?
A larger than normal amount is processed via the minor pathway, producing a large quantity of the toxic metabolite.
p.3
Pathophysiological Classification of Pain
What is neuropathic pain?
Pain that results from injury to the peripheral or central nervous system (PNS or CNS).
p.18
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)
What is the role of COX enzymes in inflammation?
They catalyze the conversion of arachidonic acid into prostaglandins, which are main inflammatory mediators.
p.23
Adverse effects of Aspirin
What gastrointestinal effects are associated with Aspirin?
Gastric distress, gastric ulceration, perforation, and bleeding leading to iron-deficiency anemia.
What are the main effects of Aspirin?
Anti-inflammatory, analgesic, and antipyretic effects.
p.31
Acetaminophen: Uses and Risks
Why do chronic alcohol abusers have a reduced ability to tolerate acetaminophen injury?
They often have preexisting liver damage.
p.27
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)
What does pregnancy category D indicate for Celecoxib?
There is positive evidence of human fetal risk, but potential benefits may warrant use in pregnant women.
p.12
Narcotic Analgesics and Their Mechanism
What are some common side effects of narcotics?
Respiratory depression, euphoria, dependence, tolerance, sedation/drowsiness, constipation, nausea, and vomiting.
p.17
Narcotic Analgesics and Their Mechanism
How can narcotics be used for dyspnea?
They can help alleviate shortness of breath.
p.30
Acetaminophen: Uses and Risks
What happens to acetaminophen at therapeutic doses?
Practically all of the drug is converted to nontoxic metabolites via the major pathway.
p.8
Nociceptive Pain Mechanisms
What role do prostaglandins play in the body?
They promote inflammation, act as potent vasodilators, and can lower blood pressure.
p.13
Narcotic Analgesics and Their Mechanism
What are the three major categories of opioid receptors?
Mu (μ), delta (δ), and kappa (κ) receptors.
p.3
Pathophysiological Classification of Pain
What psychological factors are often associated with idiopathic pain?
Anxiety, depression, and stress.
p.6
Nociceptive Pain Mechanisms
What is the function of the Reticular Activating System (RAS)?
Regulates motor function, emotions, wakefulness, and memories.
p.7
Pathophysiological Classification of Pain
What is the function of the anterolateral sensory pathway?
It transmits pain and temperature sensations.
p.30
Acetaminophen: Uses and Risks
What happens to glutathione during an acetaminophen overdose?
Glutathione is depleted, and further detoxification stops.
p.31
Acetaminophen: Uses and Risks
What happens to glutathione levels in chronic alcohol consumers?
Glutathione is depleted, impairing the liver's ability to convert toxic metabolites into nontoxic forms.
p.27
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)
What does pregnancy category C indicate for Celecoxib?
Animal studies show adverse effects on the fetus, but potential benefits may warrant use in pregnant women.
p.3
Pathophysiological Classification of Pain
What is idiopathic pain?
Nonspecific pain of unknown origin.
p.13
Narcotic Analgesics and Their Mechanism
Where are mu (μ) receptors primarily located?
In the pain-modulating centers of the CNS, mostly at supraspinal sites.
p.24
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)
What can aspirin displace in drug interactions?
Other protein-bound drugs.
p.31
Acetaminophen: Uses and Risks
What is the main risk associated with regular alcohol consumption and acetaminophen?
Increased risk of liver injury from acetaminophen, especially with excessive dosage.
p.21
Narcotic Analgesics and Their Mechanism
How does Aspirin affect COX enzymes?
It irreversibly inactivates both COXs.
p.6
Nociceptive Pain Mechanisms
What are primary sensory neurons responsible for?
Detecting stimuli that threaten the integrity of innervated tissues and transmitting sensory information from the periphery to the CNS.
p.21
Narcotic Analgesics and Their Mechanism
What is the effect of Aspirin on platelet function?
It reduces platelet function and blood clotting.
p.6
Nociceptive Pain Mechanisms
What do tertiary neurons do?
Relay information from the thalamus to the cerebral cortex where pain is integrated and modulated.
What do anticonvulsants do in the context of analgesics?
They suppress neuronal firing.
p.13
Narcotic Analgesics and Their Mechanism
Where are delta (δ) receptors located?
In the basal ganglia, neocortical regions of the brain, and dorsal horn of the spinal cord.
p.13
Narcotic Analgesics and Their Mechanism
Where are kappa (κ) receptors concentrated?
In the cerebral cortex and dorsal horn of the spinal cord.
p.2
Classification of Pain: Acute vs Chronic
How is the intensity of acute pain related to tissue damage?
The intensity of pain is proportional to the extent of tissue damage.
p.2
Classification of Pain: Acute vs Chronic
What role does acute pain serve?
It serves a protective physiologic purpose that warns of potential or actual tissue damage.
p.22
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)
What is the therapeutic dose of Aspirin that gives plasma salicylate levels?
300 mg gives plasma salicylate levels of 30–100 mg/L.
What is Celecoxib (Celebrex) classified as?
A second-generation NSAID.
p.23
Adverse effects of Aspirin
How does Aspirin affect hematology?
It inhibits platelet aggregation and prolongs bleeding time.
How does Celecoxib help with headaches?
By reducing cerebral vasodilation through decreasing PGE2.
p.17
Narcotic Analgesics and Their Mechanism
What are major therapeutic indications for narcotics in chronic pain?
Cancer pain, trigeminal neuralgia, low back pain, and palliative care for chronic pain from terminal illness.
p.5
Nociceptive Pain Mechanisms
What is modulation in the context of pain?
Signals from the brain modifying incoming pain impulses.
p.8
Nociceptive Pain Mechanisms
How does histamine contribute to pain and inflammation?
It is involved in the inflammatory response and increases the permeability of capillaries to white blood cells.
p.13
Narcotic Analgesics and Their Mechanism
What effects do mu (μ) receptors induce?
Central analgesia, euphoria, physical dependence, and respiratory depression.
p.19
Nociceptive Pain Mechanisms
Where is COX-1 primarily found?
In most tissues (constitutive).
p.19
Nociceptive Pain Mechanisms
How does COX-1 inhibition affect gastric health?
It can lead to gastric erosion and ulceration.
p.28
Acetaminophen: Uses and Risks
How are Acetaminophen and its metabolites excreted?
They are excreted in the urine.
What are the therapeutic uses of Aspirin?
Suppression of inflammation, analgesia, dysmenorrhoea, reduction of fever, suppression of platelet aggregation, reducing the risk of TIA/stroke or MI/heart attack, and prevention of colorectal cancer.
p.15
Narcotic Analgesics and Their Mechanism
What do antagonist drugs do?
They occupy receptors but do not activate them.
p.29
Acetaminophen: Uses and Risks
What happens in the major pathway of acetaminophen metabolism?
Acetaminophen undergoes conjugation with glucuronic acid and other compounds to form nontoxic metabolites.
p.27
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)
What effect does Celecoxib have on warfarin?
It increases the anticoagulation effect.
p.16
Narcotic Analgesics and Their Mechanism
What is naloxone used for?
Reversing opioid overdose.
p.3
Pathophysiological Classification of Pain
What can phantom limb pain lead to?
A lifelong battle with chronic pain.
p.21
Narcotic Analgesics and Their Mechanism
How does Aspirin contribute to cardiovascular protection?
By reducing the development of acute arterial thrombosis.
p.17
Narcotic Analgesics and Their Mechanism
What are some therapeutic indications for narcotics in acute pain?
Post-operative pain, diagnostic procedures, and myocardial infarction.
p.3
Pathophysiological Classification of Pain
What are common areas affected by idiopathic pain?
Pelvis, neck, shoulders, abdomen, and head.
p.12
Narcotic Analgesics and Their Mechanism
Can narcotics cause loss of consciousness?
Yes, they can cause sleep or loss of consciousness (narcosis).
p.12
Narcotic Analgesics and Their Mechanism
What are examples of narcotics?
Morphine, pethidine, and codeine.
What is a contraindication for using NSAIDs related to peptic ulcer disease?
Recent or current peptic ulcer disease increases the risk of GI bleeding.
p.19
Nociceptive Pain Mechanisms
What happens when COX-2 is inhibited?
It reduces inflammation, pain, and fever.
p.2
Classification of Pain: Acute vs Chronic
How is chronic pain categorized?
It is often divided into malignant (cancer) and nonmalignant (other causes).
p.30
Acetaminophen: Uses and Risks
What occurs to a small fraction of acetaminophen?
It is converted into toxic metabolites via the minor pathway.
p.24
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)
Which drugs increase the risk of gastric bleeding when taken with aspirin?
Warfarin, glucocorticoids, and alcohol.
What is the chemical name for Aspirin?
Acetylsalicylic acid (ASA).
p.31
Acetaminophen: Uses and Risks
How does alcohol affect the metabolism of acetaminophen?
Alcohol induces synthesis of the P450-containing enzyme, increasing production of acetaminophen’s toxic metabolite.
p.5
Nociceptive Pain Mechanisms
What does transmission refer to in nociceptive pain?
The conduction of action potentials from the injury site to the spinal cord and then to the brain.
p.29
Acetaminophen: Uses and Risks
What is the highly reactive metabolite formed from acetaminophen in the minor pathway?
N-acetyl-p-benzoquinoneimine.
What are the two subcategories of non-narcotic analgesics?
Anti-inflammatory (NSAIDs) and Non anti-inflammatory (antipyretic).
p.4
Nociceptive Pain Mechanisms
What is nociceptive pain?
It is the result of stimulus (e.g. chemical, thermal, mechanical) to pain receptors.
What are the brand names for Acetaminophen in the UK and USA?
Panadol (UK; HK) and Tylenol (USA; Canada).
How does Acetaminophen affect prostaglandin synthesis?
It inhibits PG synthesis in the brain (CNS) but not in the periphery.
What are some GI effects of NSAIDs?
Gastric distress, ulceration, perforation, and bleeding, which can lead to iron-deficiency anemia.
p.22
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)
What adverse effect can Aspirin induce in some individuals?
Angioedema (swelling of skin tissues).
p.24
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)
What are some contraindications for aspirin?
Peptic ulcer disease, bleeding disorder, hypersensitivity, pregnancy, children and teenagers suspected of influenza or chicken pox, elderly, history of heart failure, liver failure, and alcoholism.
p.8
Nociceptive Pain Mechanisms
Where is bradykinin primarily found?
In the gastrointestinal tract (95%), central nervous system, and blood platelets.
p.18
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)
What is the effect of tissue injury on phospholipids?
It triggers their breakdown due to the activation of phospholipase A2.
p.12
Narcotic Analgesics and Their Mechanism
What are the medical uses of narcotics?
Analgesics and suppressing cough.
p.20
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)
What distinguishes first-generation NSAIDs from second-generation NSAIDs?
First-generation NSAIDs inhibit both COX-1 and COX-2, while second-generation NSAIDs only inhibit COX-2.
p.13
Narcotic Analgesics and Their Mechanism
How does morphine produce analgesia?
Through interaction with mu (μ) receptors in the brain.
p.4
Nociceptive Pain Mechanisms
What are the four steps involved in nociception?
Transduction, transmission, perception, and modulation.
p.10
Pain Modulation and Neurotransmitters
What is the function of the descending inhibitory pathway in pain modulation?
It helps to block the pain sensation.
p.30
Acetaminophen: Uses and Risks
How does the toxic metabolite of acetaminophen get converted under normal conditions?
It undergoes rapid conversion by glutathione to a nontoxic form.
p.27
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)
What is a common adverse effect of Celecoxib (Celebrex)?
Dyspepsia and abdominal pain.
p.14
Narcotic Analgesics and Their Mechanism
In addition to the brain, where else does morphine exert its effects?
In the spinal cord, inhibiting the ascending pain pathway.
p.8
Nociceptive Pain Mechanisms
What are sensitizing chemicals?
Chemicals released from the degradation of cell membranes during tissue damage or inflammation that sensitize nociceptors.
p.18
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)
What triggers the breakdown of cell membranes during tissue injury?
The activation of the enzyme phospholipase A2.
p.5
Nociceptive Pain Mechanisms
What is perception in relation to pain?
The conscious awareness of pain.
p.20
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)
What is a ceiling effect in NSAIDs?
They have a limit to their effectiveness and do not cause physical dependence.
p.5
Nociceptive Pain Mechanisms
What are endogenous opioids?
Opioid peptides like β-endorphin, enkephalins, and dynorphins that mediate pain reduction.
p.17
Narcotic Analgesics and Their Mechanism
What is a pre-anesthetic medication?
A therapeutic indication for narcotics used before anesthesia.
p.4
Classification of Pain: Acute vs Chronic
What are the two types of nociceptive pain?
Somatic pain and visceral pain.
p.17
Narcotic Analgesics and Their Mechanism
What are the uses of narcotics in gastrointestinal issues?
They can be used to treat diarrhea and dysentery.
What medications increase the risk of GI bleeding when taken with NSAIDs?
Antiplatelets, anticoagulants, glucocorticoids, and alcohol.
p.19
Nociceptive Pain Mechanisms
What is the difference between COX-1 and COX-2 in terms of presence?
COX-1 is constitutive in most tissues, while COX-2 is inducible at the site of inflammation.
p.7
Pathophysiological Classification of Pain
What is the role of the dorsal column–medial lemniscal pathway?
It transmits signals for proprioception.
What are the therapeutic actions of Celecoxib?
Anti-inflammatory, analgesic, and antipyretic.
p.27
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)
Who should avoid taking Celecoxib?
Patients with heart diseases, stroke, or sulfa allergy.
p.3
Pathophysiological Classification of Pain
Why does phantom limb pain occur?
Because nerve endings at the site of amputation continue to send pain signals to the brain.
p.8
Nociceptive Pain Mechanisms
What functions does serotonin serve?
Acts as a neurotransmitter and neuromodulator, regulating mood, appetite, and sleep, and is involved in immediate defense and repair.
p.8
Nociceptive Pain Mechanisms
What is the role of substance P?
Involved in local immune response and acts as a neurotransmitter in the brain, spinal cord, and uterus, increasing capillary permeability.
p.20
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)
What actions do NSAIDs have?
Anti-inflammatory, antipyretic, and analgesic.
What are the generic names for Acetaminophen?
Acetaminophen and Paracetamol.
p.6
Nociceptive Pain Mechanisms
What are the three types of neurons involved in nociception?
Primary sensory neurons, secondary sensory neurons, and tertiary neurons.
p.13
Narcotic Analgesics and Their Mechanism
What effects do delta (δ) receptors induce?
Analgesia and respiratory depression.
p.4
Nociceptive Pain Mechanisms
What is nociception?
The process that a person becomes aware of the presence of pain.
p.2
Classification of Pain: Acute vs Chronic
What physiological responses are activated by acute pain?
Increased heart rate, respirations, and blood pressure due to sympathetic nervous system activation.
What is the effect of NSAIDs on patients with active bleeding disorders?
NSAIDs can decrease thromboxane A2 production, leading to reduced platelet activation and increased bleeding tendency.
p.6
Nociceptive Pain Mechanisms
What is the role of secondary sensory neurons?
To process nociceptive information and communicate with reflex networks and sensory pathways in the spinal cord.
p.23
Adverse effects of Aspirin
What is the pregnancy category of Aspirin?
Category D, which can cause premature closure of the ductus arteriosus.
p.4
Subjective Nature of Pain Experience
How do patients typically describe nociceptive pain?
As sharp, pricking, or shock-like to dull, aching, or burning.
p.19
Nociceptive Pain Mechanisms
How does COX-2 affect renal function?
It alters sodium and water handling, potentially leading to fluid retention.
What are the signs and symptoms of salicylism?
Tinnitus, headache, dizziness, and respiratory alkalosis.
What therapeutic actions does Acetaminophen have?
Analgesic and antipyretic actions, but weak anti-inflammatory effects.
Who might benefit from using Acetaminophen instead of NSAIDs?
Patients with gastric complaints/risks and those who do not require anti-inflammatory action.
p.13
Narcotic Analgesics and Their Mechanism
What effects are produced by stimulation of kappa (κ) receptors?
Analgesia, sedation, and dysphoria.
What is the risk associated with NSAID use in pregnant women?
Premature closure of the ductus arteriosus, leading to pulmonary hypertension in the newborn.
p.19
Nociceptive Pain Mechanisms
What is a consequence of inhibiting COX-1?
Reduced platelet aggregation leading to a bleeding tendency.
p.19
Nociceptive Pain Mechanisms
What role does COX-1 play in kidney function?
It helps maintain renal perfusion and function.
p.28
Acetaminophen: Uses and Risks
What is the primary site of metabolism for Acetaminophen?
The liver, with significant first-pass metabolism.
p.4
Classification of Pain: Acute vs Chronic
What is an example of visceral pain?
Deep squeeze, pressure, or aching.
What condition is linked to aspirin use in children and teenagers with viral infections?
Reye's syndrome, which is life-threatening and involves swelling of the brain and liver.
p.4
Pathophysiological Classification of Pain
Where does somatic pain originate?
From the skin, bones, joints, muscles, or connective tissues.
Does Acetaminophen affect platelet function?
No, it does not affect platelet function or increase bleeding time.
p.2
Classification of Pain: Acute vs Chronic
What defines chronic pain?
Long-term pain that lasts longer than 3 months beyond the healing process.
How does aspirin affect patients with heart failure?
Aspirin may interfere with the beneficial effects of heart failure medications like ACE inhibitors and ARBs.
p.4
Pathophysiological Classification of Pain
Where does visceral pain originate?
From the abdominal and thoracic organs.
What mechanism leads to GI effects when COX-1 is inhibited?
Inhibition of COX-1 in gastric mucosa compromises the gastric mucosal barrier against acid and pepsin.
p.2
Classification of Pain: Acute vs Chronic
What are the effects of poorly treated chronic pain?
It can affect physical, mental, social, financial, and spiritual aspects of a patient's life, causing stress, anger, chronic fatigue, and depression.
p.22
Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)
What plasma salicylate levels indicate severe toxicity?
Levels greater than 700–1400 mg/L.
