Pain Killers and Anesthetics

Question 1

Types of Pain

Answer 1

• acute pain (associated with anxiety)
• chronic pain (associated with depression)
• cancer pain

Question 2

benzodiazepines and barbituates in anesthesia

Answer 2

• both of these drugs are used to facilitate anesthesia
• Barbituates are used to induce anesthesia
• Benzodiazepines facilitate amnesia while providing sedation

Question 3

Lidocane

Answer 3

• most widely used local anesthetic
• can be topical or injectable
• supresses pain by blocking sodium channels, thereby blocking impulse conduction along the axon
• selectivity of anesthetic effects
• suppresses pain without generalized depression of nervous system

Question 4

Opioids

Answer 4

• the most effective pain relievers available
• a general term defined as any drug, natural or synthetic, that has actions similar to those of morphine
• there are 3 main classes of opioid receptors: Mu, Kappa, and Delta

Question 5

Mu Receptors

Answer 5

• activation of mu receptors causes analgesia, respiratory depression, euphoria, and sedation

Question 6

Kappa Receptors

Answer 6

• activation of kappa receptors causes analgesia and sedation

Question 7

Classification of Opioid Receptors

Answer 7

• Pure Opioid Agonist (Morphine): produces analgesia, euphoria, sedation, respiratory depression, physical dependance, and constipation
• Agonist-Antagonist Opiods (talwin): produce analgesia
• Pure opioid Antagonists (narcan): reversal of respiratory & CNS depression

Question 8

Morphine

Answer 8

• strong opioid analgesic
• produces analgesia, sedation, euphoria, respiratory depression, cough suppression, and suppression of bowel motility
• relieves pain without affecting other senses
• MOA: mimics the actions of endegenous opioid peptides, primarily at the MU site: drowsiness, pain
• can cause tolerance, and dependance, as well as abuse and addiction

Question 9

Adverse Effects of Morphine

Answer 9

• respiratory depression, constipation, orthostatic hypotension, urinary retention, cough suppresion, biliary colic, emesis, elevation of ICP, euphoria/dysphoria, sedation, miosis, and neurotoxicity

Question 10

Other Strong Opioid Agonists

Answer 10

• Fentanyl (100 times the potency of morphine)
• Oxycodone
• hydrocodone
• Tapentadol
• Propoxyphene
• Hydromorphine (Dilaudid)

Question 11

Codeine

Answer 11

• prototype for weak opioids
• mild to moderate pain control
• used for pain and cough suppression
• causes nausea and constipation

Question 12

Meperidine (Demerol)

Answer 12

• weak Mu agonist
• 10% efficiency of morphine
• causes significant anticholinergic effects
• treats postanesthetic shivering

Question 13

Tramadol

Answer 13

• nonopioid centrally acting analgesic

- combination of opioid and nonopioid mechansims, 30% binds on mu receptor and 70% increases norepiniephrine

Question 14

Opioid Reversal Agents

Answer 14

• Nalaxone (Narcan)

- Flumanzenil (Romazicon)

Question 15

Cyclooxygenase Inhibitors

Answer 15

• drugs with antiinflammatory properties
• NSAIDs
• Aspirin, ibuprofen, naproxen
• used to suppress inflammation, relieve pain, reduce fever
• adverse effects include gastric ulceration, bleeding, and renal impairment

Question 16

Aspirin

Answer 16

• underutilized and underappreciated
• MOA: nonselctive inhibitor of COX (reduces inflammation, pain and fever, and protects from MI and stroke)
• adverse effects include GI effects, bleeding, renal impairment, and Reyes’ syndrome

Question 17

COX inhibitors (ibuprofen, Naproxen)

Answer 17

• COX1 is the first generation which causes reversible inhibition
• COX 2 is the second generation which has little or no risk of gastric ulceration

Question 18

Acetaminophen

Answer 18

• Tylenol
• Does not inhibit COX, lacks anti inflammatory effects, does not inhibit platelet aggregation, and does not promote gastric ulceration
• can interact with ETOH and Warfarin
• overdose is lethal