VHS330 Exam 2 Pt. 1

Chapters 7-12

Define Opiates vs. Opioids

OpiATES: native alkaloids of the poppy plant (morphine, codeine, thebaine); OpiOIDS: opiates PLUS [semi-]synthetic derivatives

How do opioids provide the wanted effect?

Activate the endorphin receptors of the brain.

Define Agonists, Partial agonists, and Antagonists

Agonists: produce same action as endogenous substances; Partial Agonists: produce only part of the action of the endogenous substance; Antagonists: prevent action of endogenous substance

Define Narcotic

Sleep-induding substances; legally usually means illicit drugs such as CNS stimulants.

Define scheduled drug

A “controlled substance,” meaning it has the potential for abuse & is regulated by the FDA. Schedule I = highest abuse potential & Schedule V = lowest abuse potential

Define Tolerance

Desensitization of a signal pathway to stimulus/blocking by a substance; need larger dose for same effect

Define Dependence

Once tolerance develops, an individual requires the substance to maintain normal function. Can occur WITHOUT addiction.

Define Withdrawal

Symptoms that occur upon abrupt cessation of substance use upon which an individual is physiologically dependent

Define Addiction

Substance seeking behavior/continued misuse despite negative outcomes that stem from misuse.

What are the 2 pain categories?

Physiologic (in response to noxious stimul, protective/adaptivei); Pathologic (from abnormal firing of neurons in absence of stimulus, nonprotective/maladaptive).

Describe the mechanism of peripheral pain perception.

Exposure to harmful stimuli activates inflammation. Inflammatory “soup” sensed by nociceptors. Transduced to electrical signals carried by dorsal horn - spinal column. Nociceptors desensitize to signal.

Describe the mechanism for ascending pain pathways.

Nociceptors form synapses with ascending neurons in dorsal horn - spinal cord. A-fibers send sharp “first pain” signal; C-fibers send “second pain” signals (slower). [Opioids work to slow down this ascending transduction].

Describe the mechanism for descending pain pathways.

Signal reaches brain, evoking emotional response. Reward center (nucleus accumbens) responsible for aversive/rewarding behaviors; pain = aversive & opioid = reward. Reward causes habitual drive for taking opioids that activate descending pathways - desensitize to pain.

What are 2 types of chronic pain?

Allodynia (due to stimulus - atypically produces pain); Hyperalgesia (increased pain level from noxious stimuli).

What systems do opioids work with?

CNS, HEENT, Cardiovascular, GI

How do opioids affect the CNS?

Analgesia, Eu/Dysphoria, Sedation (inhibit respiratory center).

How do opioids affect the HEENT?

Miosis (pinpoint pupils), Loss of balance (disrupted vestibular apparatus)

How do opioids affect the cardiovascular system?

Descreased BP

How do opioids affect the GI system?

Decreased peristalsis & secretion

Symptoms of opioid withdrawal?

Increased pain, dysphoria, diarrhea/cramping, yawning, SNS activation (dilated pupils, goosebumps).

Symptoms of opioid overdose?

Pinpoint pupils, unconsciousness, diminished bowel sounds, respiratory depression (primary cause - death).

What should one do in the event of someone experiencing an opioid overdose?

Administer narcan, call 911, and attempt rescue breathing/chest compressions if necessary.

What are the 3 waves of the opioid epidemic?

Wave 1 (1990s): overprescription; Wave 2 (2000s): rise in heroin-related overdose; Wave 3 (2010s): rise in synthetic opioid use easier to overdose with (Fentanyl = 10x more lethal - heroin & 100x more lethal - morphine).

Which state has the highest overdose mortality rate due to opioid abuse?

West Virginia, @ 91/100k people in 2021.

What risks are associated with drug use?

HIV, Hep. C

What are One Health impacts of the opioid epidemic?

Vets’ ability to prescribe = hampered by restrictions → Schedule II-IV drugs; may experience drug seeking/diversion by both employees and clients.

Define Antimicrobial

Capable of destroying/inhibiting growth → disease-causing microbes

Define Antibiotic

An antibiotic is a medication that slowly destroys or slows the growth – bacteria

Define Empiric therapy

select an antiobiotic based upon most likely cause of infection without identifying the specific organism

Define Definitive therapy

Identify the specific organism and its sensitivity to select the most targeted antibiotic

Define prophylaxis

use of antibiotics to PREVENT infection

Define Bactericidal

Drugs kill the organism

Define Bacteriostatic

Drugs – inhibit growth, allows the hosts immune system to overcome infection

Which antibiotics inhibit bacterial cell wall synthesis?

Penicillins, Cephalosporins, Carbapenems, and the glycopeptide Vancomycin

Which antibiotics inhibit protein synthesis?

[Binding – 30 ribosomal subunits]: Aminoglycosides

Which antibiotics inhibit DNA synthesis/damage DNA?

Fluoroquinolones

What antibiotics inhibit metabolic pathways?

[via dihydrofolate reductase inhibition]: Trimethoprim/Sulfa

Compare/Contrast Gram positive and gram negative bacteria

Positive: larger/thicker membrane (easy – stain) & circular; Negative: smaller/thinner membrane (hard – stain) & ovular

Define intrinsic resistance

Resistance that is inherent and always present; EX) pathogen doesn’t contain target used by drug to exert AM effect

What are the 3 mechanisms for becoming resistant to drugs etc?

1. Mutational resistance

2. Efflux pumps

3. Resistance genes