1	Pain Management Pharmacology
2	Objectives After completing this chapter, the student should be able to: Discuss the history of pain management in prehospital care Explain the characteristics of the ideal analgesic agent for prehospital care Define the terms analgesic and narcotic Describe the analgesics available for use in prehospital care Describe and list the indications, contraindications, and dosages for the following medications used in pain management: morphine sulfate, meperidine, fentanyl citrate, nitrous oxide, nalbuphine, butorphanol tartrate, and ketorolac
3	Analgesics Morphine sulfate Meperidine (Demerol) Fentanyl citrate (Sublimaze) Nitrous oxide (Nitronox, Entonox) Nalbuphine (Nubain) Butorphanol tartrate (Stadol) Ketorolac (Toradol)
4	Morphine Sulfate
5	Class Narcotic analgesic
6	Description CNS depressant and a potent analgesic One of the most potent analgesics known to humans Has hemodynamic properties that make it extremely useful in emergency medicine
7	Mechanism of Action CNS depressant, providing both analgesia and sedation ↑ peripheral venous capacitance and ↓ venous return ↓ myocardial oxygen demand Important drug used in the treatment of pulmonary edema
8	Pharmacokinetics Onset Immediate (IV), 15-30 minutes (IM) Peak effects 20 minutes (IV), 30-60 minutes (IM) Duration 2-7 hours Half-life 1-7 hours
9	Indications Severe pain associated with: MI Kidney stones Pulmonary edema with or without pain
10	Contraindications Hypersensitivity Hypovolemia Hypotension Head injury Undiagnosed abdominal pain
11	Naloxone (Narcan) should be available in case respiratory depression occurs
12	Narcotics cross the placenta
13	Precautions Use with caution in elderly, asthma, and those who may already have or be susceptible to CNS depression
14	Side Effects Nausea Vomiting Abdominal cramps Blurred vision Constricted pupils Altered mental status Headache Respiratory depression
15	Drug Interactions CNS depression can be enhanced when administered with: Antihistamines Antiemetics Sedatives Hypnotics Barbiturates
16	Dosage – Adult Moderate to severe pain Standard dose 2-10 mg IV 5-15 mg IM
17	Meperidine Demerol
18	Class Narcotic analgesic
19	Description CNS depressant and a potent analgesic Less potent than morphine; 60-80 mg of meperidine roughly equivalent to 10 mg of morphine
20	Mechanism of Action CNS depressant, providing both analgesia and sedation
21	Mechanism of Action (cont.) Does not have the same hemodynamic properties as morphine but has the same tendency for physical dependence and abuse
22	Mechanism of Action (cont.) Because it causes respiratory depression, naloxone should be available when administered
23	Pharmacokinetics Onset 5 minutes (IV), 10 minutes (IM) Peak effects 1 hour Duration 2 hours (IV), 2-4 hours (IM) Half-life 3-5 hours
24	Indications Moderate to severe pain
25	Contraindications Hypersensitivity Undiagnosed abdominal pain Head injury MAO inhibitors
26	Precautions Respiratory depression:
27	Interactions Should not be administered to patients who are receiving or have recently received MAO inhibitors
28	Dosage Severe pain 25-50 mg IV 50-100 mg IM
29	Fentanyl Citrate Sublimaze
30	Class Narcotic analgesic
31	Description Chemically unrelated to morphine 50-100 times more potent than morphine
32	Mechanism of Action Principle actions are analgesic and sedation Alterations in respiratory rate and alveolar ventilation may last longer than analgesic effect Large doses may produce apnea
33	Pharmacokinetics Onset Immediate Peak effects 3-5 minutes (IV) Duration 30-60 minutes Half-life 6-8 hours
34	Indications Maintenance analgesia Adjunct in RSI intubation Severe pain
35	Contraindications Severe hemorrhage Shock Hypersensitivity
36	Precautions Monitor V/S May produce bradycardia Patients with liver and kidney dysfunction
37	Side Effects Respiratory depression Apnea Muscle rigidity Bradycardia
38	Interactions Additive effect with other CNS depressants Potentiation by MAOIs
39	Dosage Adult 25-100 µg (0.025-0.1 mg); direct IV slowly over at least 1 minute, preferably 2-3 minutes Pediatric 1.7-3.3 µg/kg for children 2-12 years
40	Nitrous Oxide Nitronox, Entonox
41	Class Gas
42	Description Blended mixture of 50% O₂ and 50% N₂O that has potent analgesic effects
43	Mechanism of Action CNS depressant with analgesic properties Effects last only 2-5 minutes after administration ceases
44	Pharmacokinetics Onset 2-5 minutes Peak effect 2-5 minutes Duration 2-5 minutes Half-life Unknown
45	Indications Pain of musculoskeletal origin Fractures Burns Ischemic chest pain Severe anxiety
46	Contraindications Patients that cannot comprehend verbal instructions or who are intoxicated
47	Contraindications (cont.) Possible bowel obstruction Pneumothorax COPD Head injury Altered mental status Drug intoxication
48	Precautions Use in well-ventilated area May cause nausea and vomiting
49	Side Effects Dizziness Light-headedness Altered mental status Hallucinations Nausea Vomiting
50	Interactions Can potentiate the effects of other CNS depressants
51	Dosage Self-administered until the pain is relieved or the patient discontinues the administration
52	Nalbuphine Nubain
53	Class Synthetic analgesic
54	Description Synthetic analgesic Potency equivalent to morphine on a mg to mg basis
55	Mechanism of Action Centrally acting analgesic that binds to the opiate receptors in the CNS Can cause respiratory depression in doses up to 10 mg Has antagonistic effects similar to naloxone
56	Mechanism of Action (cont.) Not regulated under Controlled Substances Act of 1970 Minimal tendency for physical dependence and abuse
57	Pharmacokinetics Onset 2-3 minutes (IV), 15 minutes (IM) Peak effects 30 minutes Duration 3-6 hours Half-life 5 hours
58	Indications Moderate to severe pain
59	Contraindications Patients with a head injury or undiagnosed abdominal pain
60	Precautions Primary precaution: Patients with impaired respiratory function Administer with caution in patients dependent on narcotics
61	Side Effects Headache Altered mental status Hypotension Bradycardia Blurred vision Respiratory depression Nausea Vomiting
62	Interactions Can potentiate the CNS depression associated with narcotics, sedatives, hypnotics, and alcohol Can cause withdrawal symptoms in patients addicted to narcotics
63	Dosage 5 mg IV initially May be augmented with additional 2-mg doses if necessary Often administered with an antiemetic agent to prevent nausea and vomiting
64	Butorphanol Tartrate Stadol
65	Class Synthetic analgesic
66	Description Synthetic analgesic used frequently in emergency medicine Is quite potent Analgesic effects of 2 mg are roughly equivalent to 10 mg of morphine
67	Mechanism of Action Centrally acting analgesic that binds to the opiate receptors Has antagonistic effects similar to naloxone, which minimizes the abuse potential
68	Pharmacokinetics Onset 2-3 minutes (IV), 10-15 minutes (IM) Peak effects 4-5 minutes (IV), 0.5-1 hour (IM) Duration 3-4 hours Half-life 3-4 hours
69	Indications Moderate to severe pain
70	Contraindications Hypersensitivity Administer with caution in patients dependent on narcotics Patients with a head injury or undiagnosed abdominal pain
71	Precautions Causes marked respiratory depression Patient with a head injury, because it may cause an increase in cerebrospinal pressure
72	Side Effects Headache Altered mental status Hypotension Bradycardia Blurred vision Respiratory depression Nausea Vomiting
73	Interactions Because of its antagonistic properties, can cause withdrawal symptoms in patients addicted to narcotics
74	Dosage Standard dose 1 mg IV every 3-4 hours 2 mg IM
75	Ketorolac Toradol
76	Class Nonsteroidal anti-inflammatory agent
77	Description The first injectable nonsteroidal anti-inflammatory drug to become available in the United States
78	Mechanism of Action Nonsteroidal anti-inflammatory drug (NSAID) Has analgesic, anti-inflammatory, and antipyretic effects Peripherally acting analgesic Does not have the sedative properties of the narcotics
79	Pharmacokinetics Onset 30 minutes Peak effects 45-60 minutes Duration Varies Half-life 4-6 hours
80	Indications Mild to moderate pain
81	Contraindications Hypersensitivity Patients with allergies to aspirin or NSAIDs, or patients currently taking aspirin or NSAIDs
82	Precautions GI irritation and hemorrhage can result from therapy with NSAIDs. Long-term use increases the incidence of serious GI side effects Is cleared through the kidneys Long-term use can result in renal impairment
83	Side Effects Edema Hypertension Rash Itching Nausea Heartburn Constipation Diarrhea Drowsiness Dizziness
84	Interactions When administered with other NSAIDs (including aspirin), can worsen the side effects IM administration has been found to reduce the diuretic response to furosemide (Lasix)
85	Dosage Typical dose 30-60 mg IM Half the original dose can be repeated every 6 hours 30 mg IV (Some practitioners use 60 mg IV)
86	Questions???