PS452 Unit 8 Opioid Pharmacology Paper Example

The Sickness Ends in a Week and the Pull Does Not: A PS452 Unit 8 Opioids Paper

[Student Name]

Purdue University Global

PS452: Psychopharmacology of Alcohol and Drugs

Unit 8 Opioids Paper

[Instructor Name]

[Date]

The writer, the unit, the patient and every detail are composite and illustrative; the sources cited are real.

Dominic

Dominic, thirty-three, came to our Albuquerque withdrawal unit in March after two overdoses in a month. He had been smoking fentanyl, sold locally as blue pills or powder, every few hours for a year, after starting with prescription opioids following a back injury at a construction job. He wanted to stop. He also told me, on his first night, that he was more afraid of withdrawal than of dying.

How Opioids Act

Opioids act mainly at mu-opioid receptors, which are found in pain pathways, in reward circuits and in the brainstem regions that control breathing (Meyer & Quenzer, 2019). Activation of mu receptors reduces pain, produces euphoria and calm, and slows breathing. In the reward system, opioids increase dopamine release partly by inhibiting the GABA neurons that normally restrain dopamine neurons.

Fentanyl is a synthetic mu agonist many times more potent than morphine, so a very small amount produces strong effects. It also enters the brain quickly. Lee et al. (2024) describe how fentanyl and related synthetic compounds have come to dominate the illicit supply in the United States and driven overdose deaths to record levels. The danger lies in the brainstem: at high enough receptor activation, breathing slows and stops. Because the amount in a pill or a pinch of powder varies, a user can take a fatal dose without knowing it, which is what nearly happened to Dominic twice in a single month.

Withdrawal

With daily use, the body adapts to constant mu-receptor activation, and when opioids are withdrawn, the systems they suppressed rebound. Withdrawal brings anxiety, restlessness, yawning, sweating, runny nose, muscle aches, stomach cramps, diarrhea, goosebumps and dilated pupils. Opioid withdrawal is rarely life-threatening in healthy adults, but it is miserable, and fear of it keeps many people using. With fentanyl, the timeline can be less predictable than with heroin.

Dominic's withdrawal was managed with buprenorphine, started once he showed clear withdrawal signs on a standard scale, which relieved his symptoms within hours.

Why Buprenorphine Had to Wait

Dominic asked why the nurse would not give him buprenorphine the moment he arrived, when he was already anxious and sweating. The answer lies in the drug's pharmacology. Buprenorphine is a partial agonist at mu receptors: it activates them, but less fully than fentanyl. It also binds very tightly, with higher affinity than most other opioids, so it pushes them off the receptors. Give buprenorphine while fentanyl still fills most receptors, and strong activation is swapped for weaker activation in one stroke, which can throw the person into sudden, severe withdrawal, called precipitated withdrawal. Waiting until withdrawal has clearly begun means that fewer receptors are occupied by fentanyl, so buprenorphine relieves symptoms instead of causing them. Fentanyl complicates this, because it is stored in fatty tissue and released slowly in heavy users, which can stretch the wait. Some programs now use very small, gradually increasing starting doses to avoid the problem. Dominic waited about twenty hours, which he called the longest night of his life, but his first dose brought relief within an hour.

Tolerance, Smoking and Overdose

Smoking fentanyl delivers the drug to the brain within seconds, like smoking crack cocaine, and lets users take many small doses through the day. Dominic's tolerance had climbed accordingly. Tolerance to euphoria and pain relief develops faster and further than tolerance to respiratory depression, so as people raise their doses to feel an effect, the margin between the dose they need and a dose that stops breathing narrows. Both of his overdoses came after short breaks, when his tolerance had dropped.

Why the Pull Outlasts the Sickness

Five days later, Dominic's physical symptoms had passed. But three weeks after discharge, when I saw him at an outpatient appointment, he said the craving was "like a voice that never shuts up," worse at night and when he felt stressed or lonely.

Kaplan and Thompson (2023) reviewed how the extended amygdala, a set of connected brain regions involved in stress and negative emotion, changes during opioid withdrawal and prolonged abstinence. Repeated cycles of use and withdrawal recruit stress systems in these regions, including signaling by corticotropin-releasing factor, norepinephrine and dynorphin. These changes produce a persistent negative emotional state, with anxiety, irritability and low mood, that can last long after physical withdrawal ends. In that state, opioids promise relief, which drives craving and relapse.

Withdrawal leaves through the body in a week; the stress it built into the brain stays much longer.

The review emphasized that much of the detailed evidence comes from animal research, where the neural changes can be measured directly, and that human studies support the broad picture of persistent negative affect during abstinence.

What It Means for Treatment

The persistence of these changes explains why detoxification alone, without ongoing treatment, so often ends in relapse, and why relapse after a period of abstinence is particularly dangerous: tolerance falls quickly, but craving does not. Lee et al. (2024) describe current treatments, including methadone, buprenorphine and extended-release naltrexone, along with approaches under study. Medications that occupy mu receptors steadily, such as buprenorphine, reduce craving and protect against overdose while the brain's stress systems recover.

Dominic left the unit on buprenorphine with an outpatient prescriber, counseling and naloxone. At his three-week visit, despite his cravings, he had not used. He said the buprenorphine made the voice "quieter, but not gone," which is about what the research would predict. He has started walking each evening with his younger brother, his counselor's suggestion for the restless hours when craving peaks.

What I Watch For on the Unit

For opioid patients, I watch vital signs for signs of oversedation in the first hours after admission, since some arrive with fentanyl still active, and for the objective signs of withdrawal the nurse scores. I also make sure every opioid patient leaves with naloxone, because the days after discharge carry high overdose risk.

Conclusion

Dominic's withdrawal followed the course mu-receptor pharmacology predicts and ended within a week with buprenorphine. His craving did not. Kaplan and Thompson's review explains how stress systems in the extended amygdala change and persist, Meyer and Quenzer explain why fentanyl stops breathing, and Lee and colleagues describe treatments that support recovery while those systems slowly heal.

References

Kaplan, G. B., & Thompson, B. L. (2023). Neuroplasticity of the extended amygdala in opioid withdrawal and prolonged opioid abstinence. Frontiers in Pharmacology, 14, Article 1253736. https://doi.org/10.3389/fphar.2023.1253736

Lee, Y. K., Gold, M. S., Blum, K., Thanos, P. K., Hanna, C., & Fuehrlein, B. S. (2024). Opioid use disorder: Current trends and potential treatments. Frontiers in Public Health, 11, Article 1274719. https://doi.org/10.3389/fpubh.2023.1274719

Meyer, J. S., & Quenzer, L. F. (2019). Psychopharmacology: Drugs, the brain, and behavior (3rd ed.). Oxford University Press.