Pain Medications: Module 4

Question 1

The 4 drug classes of pain meds:

Answer 1

Non-opioid analgesic, anti-pyretics, NSAIDs (non-steroidal Anti-Inflammatory Drugs): pain control, antipyretic (fever control), anti-inflammatory; DO NOT cause physical dependence

• salicylates
• Acetaminophen
• NSAIDs (Non-Steroidal Anti-Inflammatory Drugs)

Opioid agonists

Opioid antagonists

Anesthetic drugs: general, local, topical

Question 2

Non-opioid analgesic

-Salicylates:

Mechanism:

Adverse effects:

Caution for children:

Answer 2

pain control, antipyretic (fever control), anti-inflammatory; DO NOT cause physical dependence

• common pain medication (asprin); cheap; OTC (over-the-counter)
• inhibits synthesis of prostaglandin (chemical that sensitizes nerve cells to pain); permanently inhibits platelet aggregation (for entire life of platelet) by interfering with thromboxane A2
• GI distress, bleeding
• risk of Reye’s syndrome when given to children with flu-like symptoms or chickenpox

Question 3

Non-opioid analgesic

-Acetaminophen

Mechanism

Adverse effects

Answer 3

• Analgesic, anti-pyretic drug; OTC
• reduces pain-possibly by inhibiting prostaglandin synthesis in CNS; reduces fever by action on hypothalamus; DOES NOT affect inflammation or platelet function

rarely causes GI distress or bleeding as salicylates do; may cause severe liver toxicity

Question 4

Non-opioid analgesic

NSAIDs: 2 types

• Non-selective NSAIDs: caution in?
• Selective NSAIDs:

Mechanism:

Answer 4

• Decrease inflammation
• block COX-1 (causes GI adverse effects) and COX-2 (decreases inflammation) [ibuprofen]. Caution in children, elderly, pregnant women.
• block only COX-2
• 2 isoenzymes of cyclooxygenase (COX-1 maintains stomach lining; COX-2 causes inflammation) convert arachidonic acid to prostaglandins

Question 5

Opioid (Narcotic) Agonists:

• Adverse effects:
• Drug interactions:

Answer 5

• reduce pain by binding opiate receptors in PNS, CNS➡ mimic effects of endorphins➡ analgesia, coug suppression [codeine, hydrocodone, methadone, morphine sulfate, oxycodone]
• respiratory depression, constipation (affect smooth muscle, slowing intestinal peristalsis)
• alcohol, sedatives, hypnotics

Question 6

Opioid Agonists and Pain

In ______ _______ of spinal cord, pain neurotransmitter substance ___ ( ), released into _______ ➡ bind receptors on _____ neuron, transferring pain impulse to ______

Brain sends message stimulating ______ _______ to release endogenous _____ ( ) that bind _____ receptors on ____- neuron, inhibiting release of substance ___ and pain _____.

Synthetic opiates (Syn) help ________ opiaes (Op) by binding free ______ receptors, thus inhibiting release of substance ____ and transmission of _____ signals to brain

Answer 6

• In dorsal horn of spinal cord, pain nerostransmitter substance P (P), released into synapse ➡ binds receptors on CNS neuron, transferring pain impulse to brain.
• brain sends message stimulating spinal interneurons to release endogenous on peripheral neuron, inhibiting release of substance P and pain impulses
• Synthetic opiates (Syn) help endogenous opiates (Op) by binding free opiate receptors, thus inhibiting release of substance P and transmission of pain signals to brain.

Question 7

Opioid Antagonists

Use:

Drug abuse:

Answer 7

• Greater attraction to opiate receptors than opioids, but don’t stimulate receptors, simply displace opioids (competitive inhibition).
• opioid overdose; reverses respiratory depression/sedation, stabilizes vital signs within seconds [naloxone, naltrexone]
• if opioids still in body when take naltrexone acute withdrawal symptoms may occur.

Question 8

Opioid Antagonists: Adverse effects

• Naloxone adverse effects:
• Naltrexone adverse effects:

Answer 8

• nausea, vomiting, hypertension, tachycardia; an unconscious patient returned to consciousness abruptly after administration may hyperventilate and experience tremors.
• edema, hypertension, palpitation, shortness of breath; anxiety, depression, disorientation, headache; diarrhea, constipation, nausea, thirst, vomiting; urinary frequency; liver toxicity.

Question 9

Anesthetic Drugs: 3 groups

-General:
Inhalation-
IV-

-Local:

-Topical:
Clove oil-

Answer 9

• more precise, rapid control of control of depth of anesthesia; depress CNS ➡ loss of consciousness, muscle relaxation [nitrous oxide, halothane]
• for short term anesthesia [methohexital, midazolam, detamine, etomidate, fentanyl]

-to relieve pain in specific area [lidocaine, prilocaine, etomidate, fentanyl]

-for minor pain relief; applied directly to intact skin, mucous membrane; blocks nerve impulse transmission [dibucaine, lidocaine, tetracaine]
Clove oil: stimulates’ nerve endings, causing counter irritation that interferes with pain perception.

Question 10

Anesthetic drugs adverse effects:

Answer 10

Serious and common inhalation anesthetics adverse effect:

-Malignant hyperthermia, characterized by sudden and often lethal increase in body temperature; occurs in genetically susceptible patients and may result from a failure in calcium uptake by muscle cells