Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Chapter 4: Drugs for Pain, Fever, and Inflammation

Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Conditions Commonly Treated by Pain, Fever, and Inflammation Drugs Mild-to-moderate pain caused by injury or surgery Fever, headaches, & painful menstruation Rheumatoid arthritis Osteoarthritis Chronic pain associated with cancer, AIDS, multiple sclerosis, or sickle cell disease

Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Nonopioid Analgesics, Antipyretics, and NSAIDs Analgesics: drugs that control pain without causing patient to lose consciousness –Nonopioid: not derived from opium plant; do not cause physical dependence in patients –Opioid: synthetic or derived from opium plan; may cause physical dependence Nonsteroidal Anti-Inflammatory Drugs (NSAIDs) –Reduce redness, swelling, pain, & heat of inflammation

Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Nonopioid Analgesics, Antipyretics, and NSAIDs (cont’d) Nonopioid analgesics & NSAIDs –Stop body from producing prostaglandin, which has 2 effects: Analgesic effect: reduce pain response Anti-inflammatory effect: reduce inflammation –Are antipyretics, meaning they can reduce body temperature to control fever –Four main groups: Salicylates Nonsalicylate analgesics NSAIDs Urinary tract analgesic phenazopyridine hydrochloride

Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Nonopioid Analgesics, Antipyretics, and NSAIDs (cont’d) Salicylates –Among most commonly used medications for controlling pain, fever, & inflammation –Mainly used for following: Relieving mild-to-moderate pain Reducing fever Reducing inflammation from rheumatic fever, rheumatoid arthritis, & osteoarthritis –Relieve headache & muscles at same time –Not effective for relieving pain of organs or smooth muscles or controlling severe pain from trauma

Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Nonopioid Analgesics, Antipyretics, and NSAIDs (cont’d) Salicylates –Acetylsalicylic acid –Choline magnesium trisalicylate –Choline salicylate –Diflunisal & salsalate Adverse Reactions –Gastric distress –Nausea –Vomiting –Bleeding tendencies

Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Nonopioid Analgesics, Antipyretics, and NSAIDs (cont’d) Acetaminophen –Belongs to a group of drugs called para-aminophenol (APAP) derivatives –An OTC drug with analgesic & antipyretic properties –Affects central nervous system –Relieves fever by acting on hypothalamus –Does not have an anti-inflammatory effect –Does not affect way blood platelets work to form clots –Used to treat fever, headache, muscle ache, & general pain

Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Nonopioid Analgesics, Antipyretics, and NSAIDs (cont’d) Nonsteroidal Anti-Inflammatory Drugs –Typically used to combat inflammation –Have analgesic & antipyretic effects –May affect blood platelets, but effects are temporary –Are absorbed through GI tract –Two types Nonselective: block both COX-1 & COX-2 enzymes Selective: block only COX-2 enzymes –May cause higher risk for heart attack, stroke, or kidney problems

Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Nonopioid Analgesics, Antipyretics, and NSAIDs (cont’d) Nonselective Nonsteroidal Anti-Inflammatory Drugs –Diclofenac –Etodolac, fenoprofen, & flurbiprofen –Ibuprofen –Indomethacin –Ketoprofen, ketorolac, & meloxicam –Nabumetone –Naproxen –Oxaprozin, piroxicam, & sulindac –Misoprostol

Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Nonopioid Analgesics, Antipyretics, and NSAIDs (cont’d) Adverse Reactions to Nonselective Nonsteroidal Anti-Inflammatory Drugs –Constipation –Diarrhea –Dizziness –Drowsiness –GI upset or pain –GI bleeding –Ulcers –Headache –Nausea –Rash –Visual disturbances –Vomiting

Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Nonopioid Analgesics, Antipyretics, and NSAIDs (cont’d) Selective Nonsteroidal Anti-Inflammatory Drugs –Reduce possibility of some adverse GI effects, such as ulcers, compared with nonselective NSAIDs –Celecoxib (Celebrex) is only COX-2 inhibitor currently available –Used to relieve pain & inflammation associated with following: Osteoarthritis Rheumatoid arthritis Ankylosing spondylitis

Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Nonopioid Analgesics, Antipyretics, and NSAIDs (cont’d) Selective Nonsteroidal Anti-Inflammatory Drugs –Celecoxib (Celebrex) Adverse Reactions –Dyspepsia –Nausea –Vomiting –GI ulcers –Hypertension –Fluid retention –Peripheral edema –Dizziness –Headache

Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Nonopioid Analgesics, Antipyretics, and NSAIDs (cont’d) Phenazopyridine Hydrochloride –A dye used in commercial coloring that helps relieve symptoms associated with urinary tract infections, including: Pain Burning Urgency Frequency –Adverse reactions Yellow tinge to patient’s skin & whites of eyes Acute renal or hepatic failure

Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Opioid Agonist and Antagonist Drugs Opioid Agonists –Controlled substances used to relieve or decrease pain without causing patient to lose consciousness –Sometimes called narcotic agonists Opioid Antagonists –Drugs that work against opioid agonists to block their effects and reverse adverse reactions, such as respiratory & CNS depression Mixed Opioid Agonist-Antagonists –Act like agonists & antagonists by relieving pain & reducing risk of adverse reactions

Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Opioid Agonist and Antagonist Drugs (cont’d) Opioid Agonists –Mainly used to manage moderate-to-severe acute & chronic pain –Bind with opiate receptors in central, peripheral nervous systems –Mimic effects of endorphins, body’s natural opiates –Binding process has following effects: Antidiarrheal action Contraction of bladder & ureters Constriction of bronchial muscles Dilation of blood vessels Slowing of intestinal peristalsis & suppression of cough center

Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Opioid Agonist and Antagonist Drugs (cont’d) Opioid Agonists –Codeine –Fentanyl citrate –Hydrocodone –Hydromorphone –Levorphanol –Meperidine –Methadone –Morphine –Oxycodone –Oxymorphone –Propoxyphene –Remifentanil –Sufentanil Adverse Reactions –Constipation –Flushing –Orthostatic hypotension –Pupil constriction

Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Opioid Agonist and Antagonist Drugs (cont’d) Mixed Opioid Agonist-Antagonists –Relieve pain while reducing toxic effects & dependency –Affect CNS –Act in 2 ways at same time: At some receptor sites, they bind with receptor & produce pain relief effect similar to other opioids At other sites, they block agonist action, reducing adverse effects –Used for pain relief during childbirth & after surgery –Sometimes prescribed instead of opioid agonists because of lower risk of drug dependence

Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Opioid Agonist and Antagonist Drugs (cont’d) Mixed Opioid Agonist- Antagonists –Buprenorphine –Butorphanol & nalbuphine –Pentazocine Adverse Reactions –Euphoria –Lightheadedness –Nausea –Vomiting –Sedation

Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Opioid Agonist and Antagonist Drugs (cont’d) Opioid Antagonists –Counteract effects of opioids –Have strong attraction for opiate receptors –Don’t stimulate receptors, but fill up receptor sites so that opioids can’t bind with them (competitive inhibition) –2 most common opioid antagonists: Naloxone Naltrexone

Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Opioid Agonist and Antagonist Drugs (cont’d) Adverse Reactions –Naloxone Nausea Vomiting Hypertension Tachycardia –Naltrexone Edema, hypertension, palpitations, phlebitis, shortness of breath Anxiety, depression, disorientation, dizziness, headache, mood changes, or nervousness Anorexia, diarrhea, constipation, nausea, thirst, GI pain, cramps, vomiting Urinary frequency Liver toxicity

Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Anesthetic Drugs Block perception of pain or cause a loss of feeling Allow individual to undergo surgery or other medical procedures without distress & pain Three classes –General anesthetics Inhalation Intravenous –Local anesthetics –Topical anesthetics

Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Anesthetic Drugs (cont’d) Inhalation Anesthetics –Used for surgery –Allow precise & quick control of depth of anesthesia –Most are liquid & volatile –Move from lungs to blood; are eliminated by lungs or liver –Work by depressing CNS –Effects Loss of consciousness Loss of responsiveness to sensory stimulation Muscle relaxation

Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Anesthetic Drugs (cont’d) Inhalation Anesthetics –Desflurane –Enflurane, isoflurane, & sevoflurane –Nitrous oxide Adverse Reactions –Ataxia –Confusion –Depressed breathing & circulation –Hypothermia –Nausea –Sedation –Vomiting

Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Anesthetic Drugs (cont’d) Intravenous Anesthetics –Typically used when patient needs general anesthesia for a short period, such as outpatient surgery –Used to help induce general anesthesia more rapidly or supplement inhalation anesthetics –Different types of drugs are used as intravenous anesthetics: Barbiturates Benzodiazepines Dissociatives Hypnotics Opiates

Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Anesthetic Drugs (cont’d) Intravenous Anesthetics (& associated adverse reactions) –Methohexital & Sufentanil –Thiopental: respiratory depression; hiccups, coughing, muscle twitching; depressed cardiac function & peripheral dilation –Midazolam: CNS & respiratory depression, hypotension, dizziness –Ketamine: irrational behavior, excitement, disorientation, delirium, hallucinations, increased heart rate, hypertension –Etomidate: hiccups, coughing, muscle twitching –Propofol: respiratory depression –Fentanyl: CNS & respiratory depression, hypoventilation, cardiac arrhythmias, muscle rigidity

Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Anesthetic Drugs (cont’d) Local Anesthetics –Administered to prevent or relieve pain in a specific area of body –Often used as an alternative to general anesthesia for elderly or debilitated patients –Two main groups: “amide” drugs & “ester” drugs –Uses To prevent & relieve pain from procedures, disease, injury To treat severe pain that topical anesthetics or analgesics can’t relieve As an alternative to general anesthetics in surgery for older patients & patients with respiratory disorders

Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Anesthetic Drugs (cont’d) Local Anesthetics –Amide drugs Bupivacaine Lidocaine Mepivacaine Prilocaine Ropivacaine –Ester drugs Adverse Reactions –Shivering –Positional headache –Pain –Bradycardia –Hypotension –Anxiety –Restlessness –Palpitations –Tachycardia

Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Anesthetic Drugs (cont’d) Topical Anesthetics –Are applied directly to unbroken skin or mucous membranes to prevent or relieve minor pain –Most produce little systemic absorption –Many work by blocking nerve signals –Aren’t well absorbed into systemic circulation

Copyright © 2010 Wolters Kluwer Health | Lippincott Williams & Wilkins Anesthetic Drugs (cont’d) Topical Anesthetics –Lidocaine –Tetracaine –Benzocaine –Cocaine –Dyclonine & dibucaine –Pramoxine –Aromatic compounds –Cooling effect Adverse Reactions –A rash –Itching –Hives –Swelling of mouth & throat –Breathing difficulty