pain, cancer pain & headaches

Chapter 28: 

Chapter 28 Opioid (Narcotic) Analgesics, Opioid Antagonists, and Nonopioid Centrally Acting Analgesics

Analgesics and Opioids: 

Analgesics and Opioids Analgesics are drugs that relieve pain without causing loss of consciousness. Opioids are the most effective pain relievers available.

Introduction to the Opioids : 

Introduction to the Opioids Terminology Action Classification of drugs that act as opioid receptors Pure Opioid agonists Agonist-Antagonist Opioids Pure Opioid antagonists

Morphine: 

Morphine Source Seedpod of the poppy plant Overview of pharmacologic actions Receptors involved Pain relief Drowsiness Mental clouding Anxiety reduction Sense of well-being

Morphine: 

Morphine Adverse effects Respiratory depression Infants and elderly are especially sensitive Onset: IV 7 min; IM 30 min; subQ up to 90 min, may persist 4-5 hr Spinal injection – response may be delayed hours Tolerance to respiratory depression can develop Increased depression with concurrent use of other drugs that have CNS depressant actions ( eg , alcohol, barbiturates, benzodiazepines) Euphoria/ dysphoria Sedation Miosis Neurotoxicity Adverse effects from prolonged use Can compromise patients with impaired pulmonary function Asthma, emphysema, kyphoscoliosis , chronic cor pulmonale , bariatric

Morphine: 

Morphine Tolerance and physical dependence Tolerance Increased doses needed to obtain same response Develops with analgesia, euphoria, sedation, respiratory depression Cross-tolerance to other opioid agonists No tolerance to miosis or constipation develops

Morphine: 

Morphine Tolerance and physical dependence Physical dependence Abstinence syndrome with abrupt discontinuation About 10 hours after last dose: Initial reaction (yawning, rhinorrhea, sweating) Progresses to: Violent sneezing, weakness, nausea, vomiting, diarrhea, abdominal cramps, bone and muscle pain, muscle spasm, kicking movements Lasts 7-10 days if untreated Withdrawal unpleasant, but not lethal like potential with CNS depressants or alcohol

Morphine: 

Morphine Abuse liability Precautions Decreased respiratory reserve Pregnancy Labor and delivery Head injury Other precautions

Morphine: 

Morphine Drug interactions CNS depressants Anticholinergic drugs Hypotensive drugs Monoamine oxidase inhibitors Agonist-antagonist opioids Opioid antagonists Other interactions

Morphine: 

Morphine Toxicity Clinical manifestations Classic triad Coma Respiratory depression Pinpoint pupils Treatment Ventilatory support Antagonist – naloxone General guidelines Monitor full vitals before giving Give on a fixed schedule

Other Strong Opioid Agonists: 

Other Strong Opioid Agonists Fentanyl 100 times the potency of morphine Five formulations in three routes Parenteral Surgical anesthesia Transdermal Patch – h eat acceleration Iontophoretic system – n eedle-free Transmucosal Lozenge on a stick Buccal tablets

Other Strong Opioid Agonists: 

Other Strong Opioid Agonists Alfentanil and sufentanil Remifentanil Meperidine Short half-life Interacts adversely with several other drugs Toxic metabolite accumulation Methadone Tx for pain and opioid addicts

Other Strong Opioid Agonists: 

Other Strong Opioid Agonists Heroin Used legally in Europe to relieve pain High abuse liability Not more effective than other opioids See Figure 28-2 Hydromorphone, oxymorphone, and levorphanol Basic pharmacology Preparations, dosage, and administration

Moderate to Strong Opioid Agonists: 

Moderate to Strong Opioid Agonists Similar to morphine in most respects Produce analgesia, sedation, euphoria Can cause: Respiratory depression, constipation, urinary retention, cough suppression, and miosis Can be reversed with naloxone Different from morphine Produce less analgesia and respiratory depression than morphine Somewhat lower potential for abuse

Moderate to Strong Opioid Agonists: 

Moderate to Strong Opioid Agonists Codeine Actions and uses 10% converts to morphine in liver Pain and cough suppression Preparations, dosage, and administration Usually PO (formulated alone or with aspirin or acetaminophen) 30 mg produces same effect as 325 mg acetaminophen

Moderate to Strong Opioid Agonists: 

Moderate to Strong Opioid Agonists Oxycodone Analgesic actions equivalent to those of codeine A long-acting analgesic Immediate release Controlled release (OxyContin) Abuse: crushes and snorts or injects medication

Moderate to Strong Opioid Agonists: 

Moderate to Strong Opioid Agonists Hydrocodone Most widely prescribed drug in the United States Combined with aspirin, acetaminophen, or ibuprofen Propoxyphene Analgesic effect equal to that of aspirin Combined with aspirin or acetaminophen

Agonist-Antagonist Opioids: 

Agonist-Antagonist Opioids Pentazocine ( Talwin ) Actions and uses Preparations, dosage, and administration Butorphanol ( Stadol )

Clinical Use of Opioids : 

Clinical Use of Opioids Pain assessment Essential component of management Based on patients description Evaluate: Pain location, characteristics, duration, things that improve/worsen pain Status prior to drug and 1 hour after

Dosing Guidelines: 

Dosing Guidelines Assessment of pain Pain status should be evaluated prior to opioid administration and about 1 hour after. Dosage determination Opioid analgesics must be adjusted to accommodate individual variation. Dosing schedule As a rule, opioids should be administered on a fixed schedule. Avoiding withdrawal

Clinical Use of Opioids : 

Clinical Use of Opioids Physical dependence A state in which an abstinence syndrome will occur if the dependence-producing drug is abruptly withdrawn – NOT equated with addiction Abuse Drug use that is inconsistent with medical or social norms Addiction A behavior pattern characterized by continued use of a psychoactive substance despite physical, psychologic, or social harm

Clinical Use of Opioids: 

Clinical Use of Opioids Balance the need to provide pain relief with the desire to minimize abuse Minimize fears about: Physical dependence Abuse Addiction

Clinical Use of Opioids: 

Clinical Use of Opioids Patient-controlled analgesia PCA devices Drug selection and dosage regulations Comparison of PCA with traditional intramuscular therapy Patient education

Clinical Use of Opioids: 

Clinical Use of Opioids Using opioids in specific settings Postoperative pain Obstetric analgesia Myocardial infarction Head injury Cancer-related pain Chronic noncancer pain

Slide 25: 

Fig. 28-3. Fluctuation in opioid blood levels seen with three dosing procedures. Note that with PRN dosing, opioid levels can fluctuate widely, going from subtherapeutic to excessive and back again. In contrast, when opioids are administered with a PCA device or on a fixed schedule, levels stay within the therapeutic range, allowing continuous pain relief with minimal adverse effects.

Opioid Antagonists: 

Opioid Antagonists Drugs that block the effects of opioid agonists Principal uses: Treat opioid overdose, relief of opioid-induced constipation Reversal of post-op opioid effects Management of opioid addiction

Opioid Antagonists: 

Opioid Antagonists Naloxone ( Narcan ) Mechanism of Action

Nonopioid Centrally Acting Analgesics : 

Nonopioid Centrally Acting Analgesics Relieve pain by mechanisms largely or completely unrelated to opioid receptors Do not cause respiratory depression, physical dependence, or abuse Not regulated under the Controlled Substances Act

Nonopioid Centrally Acting Analgesics: 

Nonopioid Centrally Acting Analgesics Tramadol (Ultram) Clonidine ( Duraclon ) Ziconotide ( Prialt )

Some Final Key Thoughts: 

Some Final Key Thoughts Cross-tolerance exists among the various opioid agonists, but not between opioid agonists and general CNS depressants Use of meperidine should not exceed 48 hours – avoid toxic metabolite accumulation Opioid dosage must be individualized Administer on fixed schedule Evaluate your personal thoughts on abuse/addiction and give opioids based on patient’s need to relieve pain and suffering

Chapter 29: 

Chapter 29 Pain Management in Patients with Cancer

Management Strategy: 

Management Strategy ASK about pain regularly. Assess pain systematically BELIEVE the patient and family in their reports of pain and what relieves it. CHOOSE pain control options appropriate for the patient, family, and setting. DELIVER interventions in a timely, logical, coordinated fashion. EMPOWER patients and their families. Enable patients to control their treatment to the greatest extent possible

Assessment and Ongoing Evaluation: 

Assessment and Ongoing Evaluation Comprehensive initial assessment Intensity and character of pain Physical and neurologic exam Diagnostic tests Psychosocial assessment Pain intensity scales Ongoing evaluation Barriers to assessment

Comprehensive Initial Assessment: 

Comprehensive Initial Assessment The primary objective – to characterize the pain and identify its cause Assessment of pain intensity and character – the patient self-report Onset and temporal pattern Location Quality Intensity Modulating factors Previous treatment Impact

Slide 35: 

Fig. 29-1. Flow chart for pain management in patients with cancer. NSAID = nonsteroidal anti-inflammatory drug.

Comprehensive Initial Assessment: 

Comprehensive Initial Assessment Physical and neurologic examinations Diagnostic tests Psychosocial assessment Directed at both the patient and family Pain intensity scales

Slide 37: 

Fig. 29-2. Linear pain intensity scales. * If used as a graphic rating scale, a 10-cm baseline is recommended.

Slide 38: 

Fig. 29-3. Wong-Baker FACES pain rating scale. Explain to the patient that the first face represents a person who feels happy because he or she has no pain, and that the other faces represent people who feel sad because they have pain, ranging from a little to a lot. Explain that face 10 represents a person who hurts as much as you can imagine, but that you don ’ t have to be crying to feel this bad. Ask the patient to choose the face that best reflects how he or she is feeling. The numbers below the faces correspond to the values in the numeric pain scale shown in Figure 29–2.

Ongoing Evaluation: 

Ongoing Evaluation Reassess frequently. Evaluate after sufficient time has elapsed. Be alert for the development of new pain.

Barriers to Assessment: 

Barriers to Assessment Inaccurate reporting by patient Under-reporting by patient Language and cultural barriers

Drug Therapy: 

Drug Therapy Nonopioid analgesics Opioid analgesics Adjuvant analgesics

Drug Therapy: 

Drug Therapy WHO analgesic ladder Step 1 – mild to moderate pain Nonopioid analgesic NSAIDs and acetaminophen Step 2 – more severe pain Add opioid analgesic, oxycodone, hydrocodone Step 3 – severe pain Substitute powerful opioid – morphine, fentanyl

Slide 43: 

Fig. 29-4. The WHO analgesic ladder for cancer pain management. Note that steps represent pain intensity. Accordingly, if a patient has intense pain at the outset, then treatment can be initiated with an opioid (step 2), rather than trying a nonopioid first (step 1).

Drug Selection: 

Drug Selection Pure opioid agonists are preferred for all cancer patients Opioid rotation Dosage should be individualized Use with caution Methadone (Dolophine), levorphanol (Levo-Dromoran), codeine Avoid Meperidine (Demerol)

Managing Breakthrough Pain: 

Managing Breakthrough Pain Patients may experience transient episodes of moderate to severe breakthrough pain Access to rescue medication Strong opioid with rapid onset and short duration

Managing Side Effects: 

Managing Side Effects Respiratory depression Constipation Sedation Nausea and vomiting Other side effects

Adjuvant Analgesics: 

Adjuvant Analgesics Used to complement the effects of opioids – not used as substitutes Tricyclic antidepressants Amitriptyline (Elavil) Antiseizure drugs Local anesthetics/ antidysrhythmics CNS stimulants Antihistamines Hydroxyzine ( Vistaril ) Glucocorticoids Bisphosphonates

The Elderly: 

The Elderly Heightened drug sensitivity Undertreatment of pain Misconceptions Belief that elderly patients are insensitive to pain Belief that elderly patients can tolerate pain well Belief that elderly patients are highly sensitive to opioid side effects Increased risk of side effects and adverse interactions

Young Children: 

Young Children Assessment Verbal children Preverbal and nonverbal children Treatment

Chapter 30: 

Chapter 30 Drugs for Headache

Headache: 

Headache Common symptom Triggered by a variety of stimuli Stress, fatigue, acute illness, sensitivity to alcohol Mild episodes Relieved by OTCs (aspirin, acetaminophen) Severe headaches Migraine, cluster, tension-type

Headaches: 

Headaches Identifiable underlying causes Severe hypertension, hyperthyroidism, tumors, infection, and disorders of the eye, nose, sinuses, and throat No identifiable cause Migraine Cluster

Headaches: 

Headaches Migraine headache I: Characteristics and overview of treatment Migraine headache II: Abortive therapy Migraine headache III: Preventive therapy Cluster headaches Tension-type headache

Migraine Headache I: 

Migraine Headache I Characteristics Throbbing head pain of moderate to severe intensity Nausea and vomiting Sensitivity to light and sound Highly debilitating Hormonal component Family history typical Two primary forms Migraine with aura Preceded by visual symptoms Migraine without aura More common than with aura Pathophysiology Neurovascular disorder that involves dilation and inflammation of intracranial blood vessels Vasodilation leads to pain Neurons of the trigeminal vascular system

Migraine Headache I: 

Migraine Headache I Overview of treatment Aborting an ongoing attack Nonspecific analgesics Aspirin-like drugs and opioid analgesics Migraine-specific drugs Ergot alkaloids, serotonin 1B/1D receptor agonists (triptans) Preventing attacks from occurring Beta blockers, tricyclic antidepressants, antiepileptic drugs

Migraine Headache I: 

Migraine Headache I Non-drug measures Adequate sleep Exercise Avoiding triggers Once headache begins Dark room with ice pack to neck

Migraine Headache II: Abortive Therapy: 

Migraine Headache II: Abortive Therapy Objective: to eliminate headache pain and suppress associated nausea/vomiting Earliest treatment possible Route of administration Oral not effective due to GI distress Injection, inhalation, rectal suppository may be more effective

Selection of Drugs: 

Selection of Drugs Mild-moderate headache Aspirin-like drugs Aspirin, acetaminophen, ibuprofen, and other aspirin-like analgesics Moderate-severe Migraine-specific drug Opioid analgesics Antiemetics

Ergot Alkaloids: 

Ergot Alkaloids Ergotamine Mechanism of antimigraine action Exact mechanism unknown Therapeutic uses Drug of choice to stop an ongoing migraine Pharmacokinetics Oral, sublingual, rectal, or inhalation Adverse effects N/V, weakness in the legs, myalgia, numbness and tingling in fingers or toes, angina-like pain, tachycardia or bradycardia

Ergot Alkaloids: 

Ergot Alkaloids Dihydroergotamine Therapeutic uses Drug of choice for terminating migraine and cluster headaches Pharmacologic effects Similar to ergotamine Pharmacokinetics Only parenteral or nasal spray administration – not oral

Serotonin1B/1D Receptor Agonists: 

Serotonin 1B/1D Receptor Agonists Sumatriptan (Imitrex) Mechanism of action Binds to receptors on intracranial blood vessels and causes vasoconstriction Diminishes perivascular inflammation Therapeutic use Aborting an ongoing migraine attack to relieve headache and associated symptoms Pharmacokinetics Oral or intranasal administration

Serotonin1B/1D Receptor Agonists: 

Serotonin 1B/1D Receptor Agonists Sumatriptan (cont ’ d) Adverse effects Chest symptoms Transient “ heavy arms ” or “ chest pressure ” experienced by 50% of users Coronary vasospasm Rare angina secondary to vasospasm Teratogenesis Others Vertigo, malaise, fatigue, tingling sensations Very bad taste when taken in intranasal form

Serotonin1B/1D Receptor Agonists: 

Serotonin 1B/1D Receptor Agonists Drug interactions Ergot alkaloids, sumatriptan, other triptans (all cause vasoconstriction) Preparations, dosage, and administration Oral Nasal spray

Migraine Headache III: 

Migraine Headache III Beta blockers Preferred drugs for migraine prevention Tricyclic antidepressants Antiepileptic drugs Divalproex Topiramate Estrogens (for menstrual migraine)

Migraine Headache III: 

Migraine Headache III Other drugs for prophylaxis Calcium channel blockers Candesartan, an angiotensin II receptor blocker (ARB) Supplements Riboflavin Coenzyme Q-10 Feverfew Butterbur

Cluster Headaches: 

Cluster Headaches Characteristics Occur in a series or “ cluster ” of attacks Each attack lasts 15 minutes to 2 hours Severe, throbbing, unilateral pain near the eye Lacrimation, conjunctival redness, nasal congestion, rhinorrhea, ptosis, miosis on the same side of the headache 1-2 attacks every day for 2-3 months An attack-free interval of months to years separates each cluster Treatment Primary therapy directed at prophylaxis

Tension-Type Headache: 

Tension-Type Headache Characteristics Most common form of headache Moderate, nonthrobbing pain Usually located in a “ head band ” distribution May be episodic or chronic Treatment Nonopioid analgesics Patient teaching on how to manage stress