Module 2 Drugs that Treat Pain and Inflammation

Analgesic (Pain) Medications

Opioid agonist: (Morphine)

Antidote: Opioid antagonist (naloxone)

Pain

Assessing Pain

Monitoring Pain

Pharmacological vs Non-pharmacological Pain Treatment

Gate Theory of pain

your spinal cord acts like a “gate” that controls how much pain information reaches your brain.

• Gate open → more pain signals reach the brain → more pain

• Gate closed → fewer pain signals reach the brain → less pain

Types of Pain

Acute- Recent tissue damage or injury

Chronic- constant or intermittent pain that keeps occurring long past the expected healing

Nociceptive- direct stimulus to a pain receptor; characterized by sharp, aching, throbbing that improves as injury heals

• examples- cuts, fractures, inflammation, surgery

• Somatic (skin, muscles, bones, joins

• Visceral (internal organs)

Neuropathic- nerve injury; characterized by tingling, numbness “pins and needles’, shooting sensations

• examples: shingles, diabetic neuropathy

Psychogenic- pain that is associated with emotional, psychological, or behavioral stimuli

• stomach pain linked to anxiety

Nociceptors

Transduction- injury triggers chemical signals at the site

Transmission- signal travels via nerves to the brain

modulation- brain adjusts the intensity of signal

Perception- person consciously feels the pain

Importance of Assessment of Pain before intervention

OLDCARTS

Onset

Location

Duration

Characteristics

Aggravating factors

Relieving factors

TIming

Severity

pharmacological comfort measures

Heat/Cold therapy, Counter pressure, Walking, Music, Message etc

Controlled substances

Recall role of the DEA

Scheduled medications and the nurse’s responsibilities for administering, monitoring, and wasting

Addiction/Dependency

Abstinence Syndrome (withdraws)

• Cramping, hypertension, vomiting, fever, and anxiety

• Physically dependent on that substance

Sites of action

Narcotic medication- occupy opioid receptors (agonist) to block pain response

Ergot derivatives- constrict cranial blood vessels, and triptans bind serotonin receptors to cause vasoconstriction

Triptans- bind to serotonin receptors to cause cranial vasoconstriction

Common adverse effects and toxicities associated with narcotics, antimigraine agents

CNS system effects- dizziness, anxiety, impaired mental processes, weakness

Respiratory effects- apnea, suppressed cough reflex

CV (cardiovascular)- (migraine agents): hypertension, chest pressure vasoconstriction

GI effects: Nausea, vomiting, constipation

GU effects: ureteral spasm, urinary retention

Opioid Receptors

Mu receptor-

• Analgesia (Pain)

• Euphoria (Happiness, excitement)

• Respiratory depression

• Addiction

Kappa Receptor

• Analgesia

• Sedation

• Dysphoria

• Addiction

Delta receptor

• Analgesia

• Modulates mood

Therapeutic/Pharmacologic Class: Opioid agonists/ Opioid Analgesia

Prototype: morphine

Indications: moderate of severe pain

Mechanism of Action (MOA): Opioid (receptor) agonist; binds to opioid receptor to alter the perception and response to painful stimuli; produces CNS depression (sedative effects)

Side effects: sedation, GI complications (constipation), hypotension, urinary retention

• Life threatening: respiratory depression, addiction, abuse, neonatal opioid withdrawal/abstinence syndrome

Nursing Care: Monitor pain, vital signs, respiratory status

Interactions: Avoid using with alcohol or other CNS depressants

Antidote: naloxone (competitive antagonist)-immediate withdrawal (hypertension, tachycardia, agitation)

Patient teaching: increase fluid, fiber intake to prevent contipation

Black Box Warning

Ingestion or alcohol with morphone may increase overdose

Risk of addiction, abuse, misuse

serious, life-threatnening, or fatal respiratory depression

Prolong use during pregnacy may result in neonatal opioid withdrawal/abstinence syndrome

Therapeutic/Pharmacologic Class: Opioid Antagonist

Prototype: Naloxone

Indications: antidote for opioid overdose; reversal of CNS depression and respiratory depression

Mechanism of Action (MOA): competitively blocks the effects of opioids

Side effects: hypertension, ventricular fibrillation, nausea, vomiting

Nursing Care: monitor and treat withdrawal symptoms; naloxone has a shorter duration than most opioids; repair dosing may be needed

Interactions: Avoid using with alcohol or other CNS depressants

Anti-migraine Medications

Triptans (sumatriptan)

Ergot alkaloids (ergotamine)

MIgraine Headaches

Migraine pain (is thought to come from)

• trigeminal nerve activation → chemical release → blood vessel dilation → inflammation → pain signals to the brain

May occur with or without an aura

Unilateral, throbbing, severe, worsening with movement, sound, or light

Therapeutic/Pharmacologic Class: 5-HT₁ Agonosits (Triptans)

Prototype: Sumatriptan

Indications: migraine and cluster headaches

Mechanism of Action (MOA): intracranial vasoconstriction; acts as an agonist at 5HT₁ (a serotonin) receptor sites in intracranial blood vessels and sensory trigeminal nerves

Side effects: dizziness/vertigo, warm tingling sensation

Contraindications: peripheral vascular disease, coronary artery disease, uncontrolled hypertension

Nursing Care: Vascular medication- assess/monitor for signs that vasoconstriction is a problem (linked to peripheral ischemia)

Interactions: antidepressants that are 5-HT₁ agonist- may lead to serotonin syndrome

Patient teaching: use during a migraine as symptoms appear; lying down in a dark/quiet room will help; Report palpations or chest pain

Therapeutic/Pharmacologic Class; Ergot Alkaloids

Prototype: ergotamine

Indications: migraine and cluster headaches

Mechanism of action (MOA): intracranial vasoconstriction of dilated blood vessels by stimulating alpha-adrenergic and serotonergic (5-HT0 receptors

Side effects: GI Upset, hypertension

Contraindications: peripheral vascular disease, coronary artery disease, uncontrolled hypertension

Nursing care: Vascular medication- assess/monitor for signs that vasoconstriction is a problem (linked to peripheral ischemia)

Interactions: Interactions may occur with serotinergic antidepressants- increase the risk for serotonin syndrome

Patient teaching: report palpations or chest pain

Serotonin Syndrome

Mild to Moderate

• agitation, tremor, sweating, confusion, diarrhea

• Resolved with stopping medication and supportive care

Severe

• Hyperthermia

• Severe muscle rigidity

• Seizures

• Dangerous blood pressure/heart rate

• Multi-organ failure

• Death

Triptans vs Ergot Alkaloids

Triptans

• new medication with more specific action

• better safety profile

• Route: oral, nasal, subcutaneous

Ergot alkaloids

• reserved for patients that do not response to triptans

• Have longer lasting migraines (half-line is longer)

• Parenteral (IV) options for impatient use

Alternative/Integrative substances for pain

Cannabis

• varying legality by state

• Medial Marijuana terminology is used when referring to the treatment of manifestations of illness or other conditions using the whole, unprocessed marijuana plant or the basic extracts

• Routes- inhalation, tropical, ingestion

• schedule 1 substance under federal law; natural form is not FDA-approved; state medical programs vary

• Current legislature may change to a scheduled 3 substance

• Not recognized by the FDA- two FDA synthetic derivatives are recognized

Cannabis

Reason for use

• cachexia

• chemotherapy related nausea and vomiting

• Pain

• Neuropathies

• Spasticity

Adverse effects

• increased in heart rate

• increased appetite

• sleepiness, dizziness

• decreased blood pressure

• Hallucinations

• Dependencies

Anti-inflammatory

Corticosteroids (prednisone)

Salicylates (aspirin)

NSAIDs (Ibuprofen)

COX-2 Inhibitors (celecoxib)

Acetaminophen

Cyclooxygenase Enzymes

the enzyme responsible for converting arachidonic acid in prostaglandins which are chemical messengers involved in pain, inflammation, fever, and normal body function

Therapeutic/Pharmacologic Class: corticosteroids/glucocorticoids

Prototype: Prednisone

Indications: treats inflammatory illness/ disorders or a replacement for patients who do not naturally make enough of the naturally occurring hormone (adrenal insufficiency)

Mechanism of Action (MOA) decrease inflammation, suppresses immune response by inhibitng the release of arachidonic acid

Side effects: bone loss, weight gain/ fluid retention, hyperglycemia, hypokalemia, infection, peptic ulcer disease, adrenal gland suppression, delayed would healing, insomnia

Nursing care: do not discontinue medication suddenly. Monitor infections

Patient teaching: do not stop medication suddenly; taper off

If given too much corticosteroids

• Addisons disease, Cushing disease

Therapeutic/Pharmacologic Class: Salicylates (antipyretic; nonopioid analgesic)

Prototype: Aspirin

Indications: treats inflammatory illness/disorders; mild to moderate pain, and fever. Prophylaxis of
transient ischemic attacks (TIAs) and myocardial infarction (MI)

Mechanism of Action (MOA): inhibits the production of prostaglandins and decreases platelet
aggregation

Side effects: bleeding (blood thinning properties), GI bleeding, GI upset, rash

Salicylism- tinnitus (ringing in ears), difficulty hearing (cranial nerve VIII), vomiting, diarrhea,
respiratory alkalosis, dizziness, confusion

Salicylate toxicity- Hyperpnea, tachypnea, hemorrhage, excitement, confusion, pulmonary edema,
metabolic acidosis, respiratory, cardiac, or renal failure

Contraindications: Avoid in pregnancy unless specifically prescribed, children, PUD, bleeding
disorders

Nursing Care: Do not discontinue medication suddenly. Monitor for infections, PUD.

Patient Teaching: take with food or milk to prevent GI upset, report tinnitus, avoid taking NSAIDs
with this, do not give to < 16 yrs of age (Reye’s Syndrome)

Reye’s syndrome

occurs when aspirin interacts with a viral infection, such as influenza or chickenpox

believed that aspirin interferes with the body's ability to process fatty acids in the liver

This leads to an accumulation of fat in the liver and brain, which can cause swelling and damage

NSAID (Nonsteroidal Anti-inflammatory drugs)

Not as many side effects as corticosteroids

very commonly used

all have some level of cardiovascular, gastrointestinal, clotting, and sodium/fluid retention capabilities

Therapeutic/Pharmacologic Class: nonsteroidal anti-inflammatory agents (NSAIDs)

Prototype: ibuprofen

Indications: treatment of mild-to-moderate musculoskeletal pain or dysmenorrhea. Treatment of
inflammatory disorders, fever, pain in adults and children

Mechanism of Action: inhibits prostaglandin synthesis by blocking/inhibiting COX-1 and
COX-2; analgesia by decreasing inflammation

Side effects: GI Upset, nephrotoxicity

Contraindications: pregnancy, PUD, bleeding disorders.

Nursing Care: GI risk (bleeding ulcers, perforation)

Patient Teaching: alcohol increases stomach irritation; may cause drowsiness/dizziness report
dark or red stools

Therapeutic/Pharmacologic Class: cyclooxygenase-2 (COX-2) inhibitor

Prototype: Celecoxib

Indications: relieves signs and symptoms of osteoarthritis synthesis by inhibiting COX-2 with no inhibition of COX-1; analgesia by decreasing inflammation

Side effects: Monitor stools for bleeding, skin for rash (Stevens-Johnson syndrome)

Contraindications: allergies to NSAIDs or sulfonamides

Nursing Care: Linked to cardiovascular thrombotic events (MI, strokes) GI risk (bleeding ulcers,
perforation)

Patient teaching -do not take if HTN or heart failure (HF), Stomach Ulcers or GI bleeding,
Report rash, jaundice/flu-like symptoms