Analgesics Overview

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Questions and Answers

What is the primary reason for hypotension occurring in patients stressed by opioids?

Peripheral arterial and venous dilation (correct)

Increased cardiac output due to depression of the CNS

Direct cardiac depressant effects of opioids

Increased blood volume from fluid retention

Which opioid effect does NOT diminish with continued use?

Respiratory depression

Nausea and vomiting

Analgesia

Opioid-induced constipation (correct)

What effect do opioids have on the levels of hydrochloric acid in the stomach?

They increase gastric secretion of hydrochloric acid

They stimulate excessive hydrochloric acid production

They have no effect on gastric acid secretion

They decrease gastric secretion of hydrochloric acid (correct)

What is the primary mechanism through which opioids induce constipation?

Increased tone and decreased peristalsis in the large intestine (C) Signup and view all the answers

What effect might opioids have on the sphincter of Oddi?

Contraction and possible biliary colic (A) Signup and view all the answers

Which opioid is reported to have the most pronounced anti-shivering properties?

Meperidine (C) Signup and view all the answers

Which synthetic compound is currently used to control diarrhea with fewer CNS effects?

Diphenoxylate (C) Signup and view all the answers

What is a major concern when combining full agonists with weak partial agonists?

Diminishing analgesia (C) Signup and view all the answers

Which condition must be managed when opioids are used in cardiovascular surgeries?

Mechanical respiratory assistance (B) Signup and view all the answers

What is one of the common neuroexcitatory effects associated with opioid use?

Restlessness (C) Signup and view all the answers

What type of dependence can occur with opioid use?

Physical and psychological (C) Signup and view all the answers

Which type of opioid is contraindicated for use in patients with head injuries?

Full agonists (B) Signup and view all the answers

What is a common effect of all inhaled anesthetics on respiratory function?

Decreased tidal volume (C) Signup and view all the answers

What physiological response is decreased by inhaled anesthetics in relation to carbon dioxide?

Response to hypoxia (C) Signup and view all the answers

Which statement is true regarding the renal effects of inhaled anesthetics?

They decrease effective renal plasma flow. (D) Signup and view all the answers

What impact do inhaled anesthetics have on hepatic blood flow?

Decrease hepatic blood flow significantly. (A) Signup and view all the answers

Which of the following inhaled anesthetics is noted for its bronchodilating effects?

Halothane (A) Signup and view all the answers

How do volatile anesthetics affect cerebral blood flow?

They increase cerebral blood flow. (A) Signup and view all the answers

What is a potential concern when administering volatile anesthetics to patients with head injuries?

Increased intracranial pressure. (D) Signup and view all the answers

What is the key negative effect inhaled anesthetics have on mucociliary function?

Depression of mucociliary function. (D) Signup and view all the answers

Which inhaled anesthetic is noted for having the least effect on cerebral blood flow?

Nitrous oxide (A) Signup and view all the answers

Which of the following early symptoms are associated with hepatic damage?

Diarrhea (B) Signup and view all the answers

What is the primary antidote used for acetaminophen overdose?

N-acetylcysteine (NAC) (A) Signup and view all the answers

During general anesthesia, which of the following is NOT considered a usual effect?

Euphoria (D) Signup and view all the answers

Which physiological states are NOT typical of general anesthesia?

Increased blood pressure (A) Signup and view all the answers

In cases of renal damage from acetaminophen, which of the following is most true?

It can occur after usual doses. (D) Signup and view all the answers

What is the ideal characteristic of an anesthetic drug?

Ensures quick recovery after discontinuation (C) Signup and view all the answers

Which of the following statements about the properties of a good anesthetic is incorrect?

Should be highly flammable. (D) Signup and view all the answers

What is the effect of blocking normal reflexes during anesthesia?

It ensures the safety of the surgical procedure. (D) Signup and view all the answers

N-acetylcysteine detoxifies NAPQI by forming what type of compound?

Complex with sulfhydryl group (C) Signup and view all the answers

Study Notes

Analgesics

Analgesics are drugs that relieve pain.
They work in the central nervous system (CNS) or on peripheral pain mechanisms.
They do not significantly alter consciousness.
Types of pain:
- Chronic pain lasts longer than 1 month, examples include rheumatoid arthritis, peripheral neuropathy, cancer, and idiopathic pain.
- Acute pain resolves quickly, lasting less than 30 days.
Types of pain fibers:
- A-alpha fibers
- A-beta fibers
- A-gamma fibers
- A-delta fibers
- B-fibers
- C-fibers (most important)
Pain pathway: Pain signals travel from the periphery to the spinal cord and then to higher brain centers.
Neospinothalamic tract: Fast pain travels via Aδ fibers.
Paleospinothalamic tract: Slow pain travels via C fibers.
Slow pain is poorly localized and described as an aching, throbbing, or burning sensation.

Types of Analgesics

Class 1 (Strong Opioids/Narcotic Analgesics):
- Morphine is a prototype.
- These drugs act centrally.
- Used for severe pain (burns, tumors).
- Carry the disadvantage of addiction.
Class 2 (Weak Analgesics/NSAIDs):
- Aspirin is a prototype.
- Primarily used for musculoskeletal pain.
- Some have anti-inflammatory/anti-pyretic properties.

Opioids Receptors

Opioids interact with specific protein receptors in the CNS, peripheral nerves, and gastrointestinal tract.

Endogenous Opioids

Discovered in 1975.
Also called endorphins and are internally derived ligands.
There are three main families of endogenous opioid peptides:
- Pro-enkephalin: including Met-enkephalin and Leu-enkephalin (selective to Delta and μ receptors).
- Pro-opiomelanocortin (POMC) : endorphins (selective to Delta and μ receptors).
- Preprodynorphin: dynorphins (selective to Kappa receptors).

Opioid Classification

Strong agonists (morphine, codeine, hydromorphone)
Partial agonists (butorphanol, nalbuphine)
Antagonists (naloxone, naltrexone)

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Description

This quiz covers the fundamentals of analgesics, focusing on how they relieve pain and their workings in the central nervous system. It explores the different types of pain, pain fibers, and the pain pathway, as well as classifying various analgesics, including opioids and their mechanisms. Test your knowledge on this essential aspect of pharmacology.