Analgesics Flashcards
What are some medical uses of Opioids?
Treat moderate to severe pain. Suppress cough. Suppress diarrhea.
What is an opiate?
A drug present in opium extract.
What is an Opioid?
Any drug that acts as an opiate receptor agonist.
What drug remains the benchmark for Opioids?
Morphine
Which Opioid is believed to be the most commonly used drug in the world?
Codeine.
What is a pain sensing neuron called?
Nociceptive Neuron
Where does pain come from?
Any tissue-damaging stimulus.
How can the analgesic (pain-relieving) effects come about? (3)
- Reduced Sensation. 2. Reduced process of recognition. 3. Altered process of discrimination, memory, or judgement that follow recognition.
How do NSAIDs produce analgesic effects?
They reduce the sensation of pain mostly through changes in the peripheral sites of pain stimulus.
How do Opioids produce analgesic effects?
They reduce pain via multiple actions in the CNS.
What are the steps of the pain pathway? (2)
- Noxious (painful) stimuli activate nociceptors. 2. These activate neurons to release NT, Substance P in the dorsal horn of spinal cord.
What does substance P do?
Relays pain signal to rest of nervous system.
How does the pain signal get inhibited?
Some descending neurons release serotonin and NE to inhibit pain response. Endorphin neurons can also be triggered.
What is Fentanyl?
A very lipid-soluble Opioid. Short-acting.
What is an endorphin?
A generic term that applies to any endogenous substance that exhibits the properties of morphine.
What are Opioid receptors?
Bind endogenous endorphins and exogenous opioids.
They are widely distributed throughout CNS. G protein-coupled receptors.
What are the 3 main types of Opioid receptors?
- Mu. The best and strongest analgesic action; highest abuse liability. 2. Delta: Poor analgesia. 3. Kappa: Modest analgesic effects.
What are two examples of Pure antagonist drugs?
Naltrexone and Naloxone.
What is one example of a Partial agonist drug?
Buprenorphine.
Where and How is morphine metabolized?
In the Liver. The metabolite is 10-20x more potent.
What is the half-life of morphine?
3-5 hours.
What Opioid receptor is thought to produce the euphoric effects associated with Opiods?
The Mu receptors in the limbic dopamine reward system.
How can Opiods produce respiratory depression?
It decreases the respiratory center’s sensitivity to higher levels of CO2 in the blood.
Is acute withdrawal of Opioids lethal?
No.
What are the medical uses of Codeine?
Cough Suppressant. Combined with acetaminophen for relief of mild-moderate pain.
How much more potent is Heroin in reference to morphine?
3 times more potent.
What is Meperidine (Demerol)?
1/10th as potent as morphine.
What is Methadone?
Synthetic mu agonist.
What is Remifentanil?
10-20 minute half-life. Iv to control brief intense pain during surgery.
What is Oxycodone (Oxycontin)?
Oral agent used to treat pain.
How does methadone help those recovering from Heroin addiction?
They are given a high enough dose to relieve craving and withdrawal symptoms, but not high enough to produce euphoric effects. It has a long half-life: 24 hours.
How can Buprenorphine help those recovering from Heroin addiction?
It can relieve craving and withdrawal symptoms. Less potential for dependence than methadone.
