Pharmacology of Analgesics

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Questions and Answers

What is the primary effect of acetaminophen?

Analgesia and antipyrexia (correct)

Strong anti-inflammatory effects

Cardioprotection similar to aspirin

Stimulation of opioid receptors

Which opioid receptor subtypes are involved in modulating pain perception?

Alpha and beta receptors

Histamine and serotonin receptors

Mu, delta, and kappa receptors (correct)

Sigma and omega receptors

What is the primary function of anti-inflammatory analgesics?

To change the brain's perception of pain

To enhance the formation of blood clots

To increase blood flow to affected areas

To reduce inflammation at the site of pain (correct)

What is a consequence of using long-term NSAIDs like acetaminophen?

Increased risk of myocardial infarction Signup and view all the answers

Which of the following drugs is classified as a COX-2 inhibitor?

Celecoxib Signup and view all the answers

How do opioid receptors modulate nociceptive transmission?

By inhibiting Ca++ influx and opening K+ channels Signup and view all the answers

What is the mechanism by which NSAIDs relieve pain and inflammation?

By inhibiting cyclo-oxygenase enzymes Signup and view all the answers

What are the effects of activating mu opioid receptors?

Enhanced analgesic effects and reduced neuronal activity Signup and view all the answers

Which neurotransmitters are primarily involved in nociceptive transmission that opioids inhibit?

Substance P and glutamate Signup and view all the answers

Which analgesic is commonly used in small doses to reduce the risk of heart attacks or strokes?

Aspirin Signup and view all the answers

What potential side effect is associated with NSAIDs that favor COX-1 enzymes?

Gastrointestinal side effects Signup and view all the answers

What should be used alongside long-term NSAID therapy to protect against gastrointestinal issues?

GI cytoprotectives Signup and view all the answers

What is the role of endogenous ligands in relation to opioid receptors?

They bind to opioid receptors and produce analgesia Signup and view all the answers

Opioids work primarily by affecting which aspect of the body?

Changing the perception of pain Signup and view all the answers

Which of the following is a potential issue with higher dosages of NSAIDs?

Increased risk of gastrointestinal bleeding Signup and view all the answers

Which opioid is known for its use in treating severe pain and is derived from opium?

Morphine Signup and view all the answers

Study Notes

Analgesics Pharmacology

Analgesics are medications that reduce pain.
Two major groups of analgesics: anti-inflammatory analgesics and opioid analgesics.

Anti-inflammatory Analgesics

These drugs reduce inflammation at the pain site.
Examples include: acetaminophen, aspirin, COX-2 inhibitors, and NSAIDs (such as ibuprofen and naproxen).
NSAIDs work by blocking cyclo-oxygenase (COX) enzymes. COX enzymes create prostaglandins. Prostaglandins control various processes, including inflammation, blood flow, and blood clot formation.
Nonselective NSAIDs inhibit both COX-1 and COX-2. Selective NSAIDs (COX-2 inhibitors) primarily inhibit COX-2, reducing gastrointestinal side effects but possibly increasing cardiovascular risk.
Aspirin is an NSAID that, in small doses, reduces the risk of heart attacks and strokes.
Acetaminophen primarily inhibits brain COX, is good for mild to moderate pain, and is generally well-tolerated.

Opioid Analgesics

Also called narcotics, they change the brain's perception of pain.
Examples include: morphine, codeine, fentanyl, hydrocodone, meperidine, methadone, naloxone, and naltrexone.
Opioid analgesics work on three major receptor classes: μ, δ, and κ.
Each receptor has endogenous ligands like endorphin (μ) and dynorphin (κ).
μ, κ, and δ receptors modulate pain perception.
μ receptors have subtypes (μ1 and μ2).
δ receptors have subtypes (δ1 and δ2).
κ receptors have subtypes (κ1, κ2, and κ3).
Activation of opioid receptors affects nociceptive transmission in the following ways:
- Inhibits calcium influx into presynaptic terminals to reduce neurotransmitter release.
- Opens potassium channels to hyperpolarize postsynaptic neurons, making them less responsive.
Common side effects of opioid analgesics include euphoria, dysphoria, sedation, respiratory depression, constipation, suppression of endocrine systems, cardiovascular issues (like bradycardia), convulsions, nausea, vomiting, pruritus (itching), and miosis (pinpoint pupils).
Repeated exposure to opioids can lead to tolerance, requiring higher doses for the same analgesic effect.

Cautions and Contraindications

Opioid analgesics should be used with caution in patients with bronchial asthma, heavy pulmonary secretions, convulsive disorders, biliary obstruction, head injuries, and a history of allergies to the drugs.
Opioid analgesics should also be used with caution in elderly patients and pregnant women.

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Description

This quiz explores the pharmacology of analgesics, focusing on both anti-inflammatory and opioid analgesics. Learn about different medications, their functions, and the mechanisms behind pain relief. Test your knowledge on NSAIDs, COX inhibitors, and the role of opioids in pain management.